From: Keith Randall Date: Tue, 8 Sep 2015 22:42:53 +0000 (-0700) Subject: [dev.ssa] Merge remote-tracking branch 'origin/master' into mergebranch X-Git-Tag: go1.7beta1~1623^2^2~186 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=0ec72b6b9dcf0ffee1eca400deb4867010c45c6e;p=gostls13.git [dev.ssa] Merge remote-tracking branch 'origin/master' into mergebranch Semi-regular merge of master into dev.ssa. Change-Id: I48aa17700096a14f2a20ad07491ebfcd7529f6d5 --- 0ec72b6b9dcf0ffee1eca400deb4867010c45c6e diff --cc src/cmd/compile/internal/gc/ssa.go index a554a1dfd9,0000000000..96d62041d6 mode 100644,000000..100644 --- a/src/cmd/compile/internal/gc/ssa.go +++ b/src/cmd/compile/internal/gc/ssa.go @@@ -1,3799 -1,0 +1,3799 @@@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gc + +import ( + "bytes" + "fmt" + "html" + "math" + "os" + "strings" + + "cmd/compile/internal/ssa" + "cmd/internal/obj" + "cmd/internal/obj/x86" +) + +// buildssa builds an SSA function +// and reports whether it should be used. +// Once the SSA implementation is complete, +// it will never return nil, and the bool can be removed. +func buildssa(fn *Node) (ssafn *ssa.Func, usessa bool) { + name := fn.Func.Nname.Sym.Name + usessa = strings.HasSuffix(name, "_ssa") || name == os.Getenv("GOSSAFUNC") + + if usessa { + fmt.Println("generating SSA for", name) + dumplist("buildssa-enter", fn.Func.Enter) + dumplist("buildssa-body", fn.Nbody) + } + + var s state + s.pushLine(fn.Lineno) + defer s.popLine() + + // TODO(khr): build config just once at the start of the compiler binary + + var e ssaExport + e.log = usessa + s.config = ssa.NewConfig(Thearch.Thestring, &e) + s.f = s.config.NewFunc() + s.f.Name = name + + if name == os.Getenv("GOSSAFUNC") { + // TODO: tempfile? it is handy to have the location + // of this file be stable, so you can just reload in the browser. + s.config.HTML = ssa.NewHTMLWriter("ssa.html", &s, name) + // TODO: generate and print a mapping from nodes to values and blocks + } + defer func() { + if !usessa { + s.config.HTML.Close() + } + }() + + // If SSA support for the function is incomplete, + // assume that any panics are due to violated + // invariants. Swallow them silently. + defer func() { + if err := recover(); err != nil { + if !e.unimplemented { + panic(err) + } + } + }() + + // We construct SSA using an algorithm similar to + // Brau, Buchwald, Hack, Leißa, Mallon, and Zwinkau + // http://pp.info.uni-karlsruhe.de/uploads/publikationen/braun13cc.pdf + // TODO: check this comment + + // Allocate starting block + s.f.Entry = s.f.NewBlock(ssa.BlockPlain) + + // Allocate exit block + s.exit = s.f.NewBlock(ssa.BlockExit) + + // Allocate starting values + s.vars = map[*Node]*ssa.Value{} + s.labels = map[string]*ssaLabel{} + s.labeledNodes = map[*Node]*ssaLabel{} + s.startmem = s.entryNewValue0(ssa.OpArg, ssa.TypeMem) + s.sp = s.entryNewValue0(ssa.OpSP, Types[TUINTPTR]) // TODO: use generic pointer type (unsafe.Pointer?) instead + s.sb = s.entryNewValue0(ssa.OpSB, Types[TUINTPTR]) + + // Generate addresses of local declarations + s.decladdrs = map[*Node]*ssa.Value{} + for d := fn.Func.Dcl; d != nil; d = d.Next { + n := d.N + switch n.Class { + case PPARAM, PPARAMOUT: + aux := &ssa.ArgSymbol{Typ: n.Type, Node: n} + s.decladdrs[n] = s.entryNewValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sp) + case PAUTO: + // processed at each use, to prevent Addr coming + // before the decl. + case PFUNC: + // local function - already handled by frontend + default: + str := "" + if n.Class&PHEAP != 0 { + str = ",heap" + } + s.Unimplementedf("local variable with class %s%s unimplemented", classnames[n.Class&^PHEAP], str) + } + } + // nodfp is a special argument which is the function's FP. + aux := &ssa.ArgSymbol{Typ: Types[TUINTPTR], Node: nodfp} + s.decladdrs[nodfp] = s.entryNewValue1A(ssa.OpAddr, Types[TUINTPTR], aux, s.sp) + + // Convert the AST-based IR to the SSA-based IR + s.startBlock(s.f.Entry) + s.stmtList(fn.Func.Enter) + s.stmtList(fn.Nbody) + + // fallthrough to exit + if b := s.endBlock(); b != nil { + b.Kind = ssa.BlockRet + b.AddEdgeTo(s.exit) + } + + // Finish up exit block + s.startBlock(s.exit) + s.exit.Control = s.mem() + s.endBlock() + + // Check that we used all labels + for name, lab := range s.labels { + if !lab.used() && !lab.reported { + yyerrorl(int(lab.defNode.Lineno), "label %v defined and not used", name) + lab.reported = true + } + if lab.used() && !lab.defined() && !lab.reported { + yyerrorl(int(lab.useNode.Lineno), "label %v not defined", name) + lab.reported = true + } + } + + // Check any forward gotos. Non-forward gotos have already been checked. + for _, n := range s.fwdGotos { + lab := s.labels[n.Left.Sym.Name] + // If the label is undefined, we have already have printed an error. + if lab.defined() { + s.checkgoto(n, lab.defNode) + } + } + + if nerrors > 0 { + return nil, false + } + + // Link up variable uses to variable definitions + s.linkForwardReferences() + + // Main call to ssa package to compile function + ssa.Compile(s.f) + + // Calculate stats about what percentage of functions SSA handles. + if false { + fmt.Printf("SSA implemented: %t\n", !e.unimplemented) + } + + if e.unimplemented { + return nil, false + } + + // TODO: enable codegen more broadly once the codegen stabilizes + // and runtime support is in (gc maps, write barriers, etc.) + return s.f, usessa || localpkg.Name == os.Getenv("GOSSAPKG") +} + +type state struct { + // configuration (arch) information + config *ssa.Config + + // function we're building + f *ssa.Func + + // exit block that "return" jumps to (and panics jump to) + exit *ssa.Block + + // labels and labeled control flow nodes (OFOR, OSWITCH, OSELECT) in f + labels map[string]*ssaLabel + labeledNodes map[*Node]*ssaLabel + + // gotos that jump forward; required for deferred checkgoto calls + fwdGotos []*Node + + // unlabeled break and continue statement tracking + breakTo *ssa.Block // current target for plain break statement + continueTo *ssa.Block // current target for plain continue statement + + // current location where we're interpreting the AST + curBlock *ssa.Block + + // variable assignments in the current block (map from variable symbol to ssa value) + // *Node is the unique identifier (an ONAME Node) for the variable. + vars map[*Node]*ssa.Value + + // all defined variables at the end of each block. Indexed by block ID. + defvars []map[*Node]*ssa.Value + + // addresses of PPARAM and PPARAMOUT variables. + decladdrs map[*Node]*ssa.Value + + // starting values. Memory, frame pointer, and stack pointer + startmem *ssa.Value + sp *ssa.Value + sb *ssa.Value + + // line number stack. The current line number is top of stack + line []int32 +} + +type ssaLabel struct { + target *ssa.Block // block identified by this label + breakTarget *ssa.Block // block to break to in control flow node identified by this label + continueTarget *ssa.Block // block to continue to in control flow node identified by this label + defNode *Node // label definition Node (OLABEL) + // Label use Node (OGOTO, OBREAK, OCONTINUE). + // Used only for error detection and reporting. + // There might be multiple uses, but we only need to track one. + useNode *Node + reported bool // reported indicates whether an error has already been reported for this label +} + +// defined reports whether the label has a definition (OLABEL node). +func (l *ssaLabel) defined() bool { return l.defNode != nil } + +// used reports whether the label has a use (OGOTO, OBREAK, or OCONTINUE node). +func (l *ssaLabel) used() bool { return l.useNode != nil } + +// label returns the label associated with sym, creating it if necessary. +func (s *state) label(sym *Sym) *ssaLabel { + lab := s.labels[sym.Name] + if lab == nil { + lab = new(ssaLabel) + s.labels[sym.Name] = lab + } + return lab +} + +func (s *state) Logf(msg string, args ...interface{}) { s.config.Logf(msg, args...) } +func (s *state) Fatalf(msg string, args ...interface{}) { s.config.Fatalf(msg, args...) } +func (s *state) Unimplementedf(msg string, args ...interface{}) { s.config.Unimplementedf(msg, args...) } + +// dummy node for the memory variable +var memvar = Node{Op: ONAME, Sym: &Sym{Name: "mem"}} + +// startBlock sets the current block we're generating code in to b. +func (s *state) startBlock(b *ssa.Block) { + if s.curBlock != nil { + s.Fatalf("starting block %v when block %v has not ended", b, s.curBlock) + } + s.curBlock = b + s.vars = map[*Node]*ssa.Value{} +} + +// endBlock marks the end of generating code for the current block. +// Returns the (former) current block. Returns nil if there is no current +// block, i.e. if no code flows to the current execution point. +func (s *state) endBlock() *ssa.Block { + b := s.curBlock + if b == nil { + return nil + } + for len(s.defvars) <= int(b.ID) { + s.defvars = append(s.defvars, nil) + } + s.defvars[b.ID] = s.vars + s.curBlock = nil + s.vars = nil + b.Line = s.peekLine() + return b +} + +// pushLine pushes a line number on the line number stack. +func (s *state) pushLine(line int32) { + s.line = append(s.line, line) +} + +// popLine pops the top of the line number stack. +func (s *state) popLine() { + s.line = s.line[:len(s.line)-1] +} + +// peekLine peek the top of the line number stack. +func (s *state) peekLine() int32 { + return s.line[len(s.line)-1] +} + +func (s *state) Error(msg string, args ...interface{}) { + yyerrorl(int(s.peekLine()), msg, args...) +} + +// newValue0 adds a new value with no arguments to the current block. +func (s *state) newValue0(op ssa.Op, t ssa.Type) *ssa.Value { + return s.curBlock.NewValue0(s.peekLine(), op, t) +} + +// newValue0A adds a new value with no arguments and an aux value to the current block. +func (s *state) newValue0A(op ssa.Op, t ssa.Type, aux interface{}) *ssa.Value { + return s.curBlock.NewValue0A(s.peekLine(), op, t, aux) +} + +// newValue0I adds a new value with no arguments and an auxint value to the current block. +func (s *state) newValue0I(op ssa.Op, t ssa.Type, auxint int64) *ssa.Value { + return s.curBlock.NewValue0I(s.peekLine(), op, t, auxint) +} + +// newValue1 adds a new value with one argument to the current block. +func (s *state) newValue1(op ssa.Op, t ssa.Type, arg *ssa.Value) *ssa.Value { + return s.curBlock.NewValue1(s.peekLine(), op, t, arg) +} + +// newValue1A adds a new value with one argument and an aux value to the current block. +func (s *state) newValue1A(op ssa.Op, t ssa.Type, aux interface{}, arg *ssa.Value) *ssa.Value { + return s.curBlock.NewValue1A(s.peekLine(), op, t, aux, arg) +} + +// newValue1I adds a new value with one argument and an auxint value to the current block. +func (s *state) newValue1I(op ssa.Op, t ssa.Type, aux int64, arg *ssa.Value) *ssa.Value { + return s.curBlock.NewValue1I(s.peekLine(), op, t, aux, arg) +} + +// newValue2 adds a new value with two arguments to the current block. +func (s *state) newValue2(op ssa.Op, t ssa.Type, arg0, arg1 *ssa.Value) *ssa.Value { + return s.curBlock.NewValue2(s.peekLine(), op, t, arg0, arg1) +} + +// newValue2I adds a new value with two arguments and an auxint value to the current block. +func (s *state) newValue2I(op ssa.Op, t ssa.Type, aux int64, arg0, arg1 *ssa.Value) *ssa.Value { + return s.curBlock.NewValue2I(s.peekLine(), op, t, aux, arg0, arg1) +} + +// newValue3 adds a new value with three arguments to the current block. +func (s *state) newValue3(op ssa.Op, t ssa.Type, arg0, arg1, arg2 *ssa.Value) *ssa.Value { + return s.curBlock.NewValue3(s.peekLine(), op, t, arg0, arg1, arg2) +} + +// newValue3I adds a new value with three arguments and an auxint value to the current block. +func (s *state) newValue3I(op ssa.Op, t ssa.Type, aux int64, arg0, arg1, arg2 *ssa.Value) *ssa.Value { + return s.curBlock.NewValue3I(s.peekLine(), op, t, aux, arg0, arg1, arg2) +} + +// entryNewValue0 adds a new value with no arguments to the entry block. +func (s *state) entryNewValue0(op ssa.Op, t ssa.Type) *ssa.Value { + return s.f.Entry.NewValue0(s.peekLine(), op, t) +} + +// entryNewValue0A adds a new value with no arguments and an aux value to the entry block. +func (s *state) entryNewValue0A(op ssa.Op, t ssa.Type, aux interface{}) *ssa.Value { + return s.f.Entry.NewValue0A(s.peekLine(), op, t, aux) +} + +// entryNewValue0I adds a new value with no arguments and an auxint value to the entry block. +func (s *state) entryNewValue0I(op ssa.Op, t ssa.Type, auxint int64) *ssa.Value { + return s.f.Entry.NewValue0I(s.peekLine(), op, t, auxint) +} + +// entryNewValue1 adds a new value with one argument to the entry block. +func (s *state) entryNewValue1(op ssa.Op, t ssa.Type, arg *ssa.Value) *ssa.Value { + return s.f.Entry.NewValue1(s.peekLine(), op, t, arg) +} + +// entryNewValue1 adds a new value with one argument and an auxint value to the entry block. +func (s *state) entryNewValue1I(op ssa.Op, t ssa.Type, auxint int64, arg *ssa.Value) *ssa.Value { + return s.f.Entry.NewValue1I(s.peekLine(), op, t, auxint, arg) +} + +// entryNewValue1A adds a new value with one argument and an aux value to the entry block. +func (s *state) entryNewValue1A(op ssa.Op, t ssa.Type, aux interface{}, arg *ssa.Value) *ssa.Value { + return s.f.Entry.NewValue1A(s.peekLine(), op, t, aux, arg) +} + +// entryNewValue2 adds a new value with two arguments to the entry block. +func (s *state) entryNewValue2(op ssa.Op, t ssa.Type, arg0, arg1 *ssa.Value) *ssa.Value { + return s.f.Entry.NewValue2(s.peekLine(), op, t, arg0, arg1) +} + +// constInt* routines add a new const int value to the entry block. +func (s *state) constInt8(t ssa.Type, c int8) *ssa.Value { + return s.f.ConstInt8(s.peekLine(), t, c) +} +func (s *state) constInt16(t ssa.Type, c int16) *ssa.Value { + return s.f.ConstInt16(s.peekLine(), t, c) +} +func (s *state) constInt32(t ssa.Type, c int32) *ssa.Value { + return s.f.ConstInt32(s.peekLine(), t, c) +} +func (s *state) constInt64(t ssa.Type, c int64) *ssa.Value { + return s.f.ConstInt64(s.peekLine(), t, c) +} +func (s *state) constFloat32(t ssa.Type, c float64) *ssa.Value { + return s.f.ConstFloat32(s.peekLine(), t, c) +} +func (s *state) constFloat64(t ssa.Type, c float64) *ssa.Value { + return s.f.ConstFloat64(s.peekLine(), t, c) +} +func (s *state) constIntPtr(t ssa.Type, c int64) *ssa.Value { + if s.config.PtrSize == 4 && int64(int32(c)) != c { + s.Fatalf("pointer constant too big %d", c) + } + return s.f.ConstIntPtr(s.peekLine(), t, c) +} +func (s *state) constInt(t ssa.Type, c int64) *ssa.Value { + if s.config.IntSize == 8 { + return s.constInt64(t, c) + } + if int64(int32(c)) != c { + s.Fatalf("integer constant too big %d", c) + } + return s.constInt32(t, int32(c)) +} + +// ssaStmtList converts the statement n to SSA and adds it to s. +func (s *state) stmtList(l *NodeList) { + for ; l != nil; l = l.Next { + s.stmt(l.N) + } +} + +// ssaStmt converts the statement n to SSA and adds it to s. +func (s *state) stmt(n *Node) { + s.pushLine(n.Lineno) + defer s.popLine() + + // If s.curBlock is nil, then we're about to generate dead code. + // We can't just short-circuit here, though, + // because we check labels and gotos as part of SSA generation. + // Provide a block for the dead code so that we don't have + // to add special cases everywhere else. + if s.curBlock == nil { + dead := s.f.NewBlock(ssa.BlockPlain) + s.startBlock(dead) + } + + s.stmtList(n.Ninit) + switch n.Op { + + case OBLOCK: + s.stmtList(n.List) + + // No-ops + case OEMPTY, ODCLCONST, ODCLTYPE, OFALL: + + // Expression statements + case OCALLFUNC, OCALLMETH, OCALLINTER: + s.expr(n) + + case ODCL: + if n.Left.Class&PHEAP == 0 { + return + } + if compiling_runtime != 0 { - Fatal("%v escapes to heap, not allowed in runtime.", n) ++ Fatalf("%v escapes to heap, not allowed in runtime.", n) + } + + // TODO: the old pass hides the details of PHEAP + // variables behind ONAME nodes. Figure out if it's better + // to rewrite the tree and make the heapaddr construct explicit + // or to keep this detail hidden behind the scenes. + palloc := prealloc[n.Left] + if palloc == nil { + palloc = callnew(n.Left.Type) + prealloc[n.Left] = palloc + } + s.assign(OAS, n.Left.Name.Heapaddr, palloc) + + case OLABEL: + sym := n.Left.Sym + + if isblanksym(sym) { + // Empty identifier is valid but useless. + // See issues 11589, 11593. + return + } + + lab := s.label(sym) + + // Associate label with its control flow node, if any + if ctl := n.Name.Defn; ctl != nil { + switch ctl.Op { + case OFOR, OSWITCH, OSELECT: + s.labeledNodes[ctl] = lab + } + } + + if !lab.defined() { + lab.defNode = n + } else { + s.Error("label %v already defined at %v", sym, Ctxt.Line(int(lab.defNode.Lineno))) + lab.reported = true + } + // The label might already have a target block via a goto. + if lab.target == nil { + lab.target = s.f.NewBlock(ssa.BlockPlain) + } + + // go to that label (we pretend "label:" is preceded by "goto label") + b := s.endBlock() + b.AddEdgeTo(lab.target) + s.startBlock(lab.target) + + case OGOTO: + sym := n.Left.Sym + + lab := s.label(sym) + if lab.target == nil { + lab.target = s.f.NewBlock(ssa.BlockPlain) + } + if !lab.used() { + lab.useNode = n + } + + if lab.defined() { + s.checkgoto(n, lab.defNode) + } else { + s.fwdGotos = append(s.fwdGotos, n) + } + + b := s.endBlock() + b.AddEdgeTo(lab.target) + + case OAS, OASWB: + // Check whether we can generate static data rather than code. + // If so, ignore n and defer data generation until codegen. + // Failure to do this causes writes to readonly symbols. + if gen_as_init(n, true) { + var data []*Node + if s.f.StaticData != nil { + data = s.f.StaticData.([]*Node) + } + s.f.StaticData = append(data, n) + return + } + s.assign(n.Op, n.Left, n.Right) + + case OIF: + cond := s.expr(n.Left) + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Control = cond + b.Likely = ssa.BranchPrediction(n.Likely) // gc and ssa both use -1/0/+1 for likeliness + + bThen := s.f.NewBlock(ssa.BlockPlain) + bEnd := s.f.NewBlock(ssa.BlockPlain) + var bElse *ssa.Block + + if n.Rlist == nil { + b.AddEdgeTo(bThen) + b.AddEdgeTo(bEnd) + } else { + bElse = s.f.NewBlock(ssa.BlockPlain) + b.AddEdgeTo(bThen) + b.AddEdgeTo(bElse) + } + + s.startBlock(bThen) + s.stmtList(n.Nbody) + if b := s.endBlock(); b != nil { + b.AddEdgeTo(bEnd) + } + + if n.Rlist != nil { + s.startBlock(bElse) + s.stmtList(n.Rlist) + if b := s.endBlock(); b != nil { + b.AddEdgeTo(bEnd) + } + } + s.startBlock(bEnd) + + case ORETURN: + s.stmtList(n.List) + b := s.endBlock() + b.Kind = ssa.BlockRet + b.AddEdgeTo(s.exit) + + case OCONTINUE, OBREAK: + var op string + var to *ssa.Block + switch n.Op { + case OCONTINUE: + op = "continue" + to = s.continueTo + case OBREAK: + op = "break" + to = s.breakTo + } + if n.Left == nil { + // plain break/continue + if to == nil { + s.Error("%s is not in a loop", op) + return + } + // nothing to do; "to" is already the correct target + } else { + // labeled break/continue; look up the target + sym := n.Left.Sym + lab := s.label(sym) + if !lab.used() { + lab.useNode = n.Left + } + if !lab.defined() { + s.Error("%s label not defined: %v", op, sym) + lab.reported = true + return + } + switch n.Op { + case OCONTINUE: + to = lab.continueTarget + case OBREAK: + to = lab.breakTarget + } + if to == nil { + // Valid label but not usable with a break/continue here, e.g.: + // for { + // continue abc + // } + // abc: + // for {} + s.Error("invalid %s label %v", op, sym) + lab.reported = true + return + } + } + + b := s.endBlock() + b.AddEdgeTo(to) + + case OFOR: + // OFOR: for Ninit; Left; Right { Nbody } + bCond := s.f.NewBlock(ssa.BlockPlain) + bBody := s.f.NewBlock(ssa.BlockPlain) + bIncr := s.f.NewBlock(ssa.BlockPlain) + bEnd := s.f.NewBlock(ssa.BlockPlain) + + // first, jump to condition test + b := s.endBlock() + b.AddEdgeTo(bCond) + + // generate code to test condition + s.startBlock(bCond) + var cond *ssa.Value + if n.Left != nil { + cond = s.expr(n.Left) + } else { + cond = s.entryNewValue0I(ssa.OpConstBool, Types[TBOOL], 1) // 1 = true + } + b = s.endBlock() + b.Kind = ssa.BlockIf + b.Control = cond + b.Likely = ssa.BranchLikely + b.AddEdgeTo(bBody) + b.AddEdgeTo(bEnd) + + // set up for continue/break in body + prevContinue := s.continueTo + prevBreak := s.breakTo + s.continueTo = bIncr + s.breakTo = bEnd + lab := s.labeledNodes[n] + if lab != nil { + // labeled for loop + lab.continueTarget = bIncr + lab.breakTarget = bEnd + } + + // generate body + s.startBlock(bBody) + s.stmtList(n.Nbody) + + // tear down continue/break + s.continueTo = prevContinue + s.breakTo = prevBreak + if lab != nil { + lab.continueTarget = nil + lab.breakTarget = nil + } + + // done with body, goto incr + if b := s.endBlock(); b != nil { + b.AddEdgeTo(bIncr) + } + + // generate incr + s.startBlock(bIncr) + if n.Right != nil { + s.stmt(n.Right) + } + if b := s.endBlock(); b != nil { + b.AddEdgeTo(bCond) + } + s.startBlock(bEnd) + + case OSWITCH, OSELECT: + // These have been mostly rewritten by the front end into their Nbody fields. + // Our main task is to correctly hook up any break statements. + bEnd := s.f.NewBlock(ssa.BlockPlain) + + prevBreak := s.breakTo + s.breakTo = bEnd + lab := s.labeledNodes[n] + if lab != nil { + // labeled + lab.breakTarget = bEnd + } + + // generate body code + s.stmtList(n.Nbody) + + s.breakTo = prevBreak + if lab != nil { + lab.breakTarget = nil + } + + if b := s.endBlock(); b != nil { + b.AddEdgeTo(bEnd) + } + s.startBlock(bEnd) + + case OVARKILL: + // Insert a varkill op to record that a variable is no longer live. + // We only care about liveness info at call sites, so putting the + // varkill in the store chain is enough to keep it correctly ordered + // with respect to call ops. + s.vars[&memvar] = s.newValue1A(ssa.OpVarKill, ssa.TypeMem, n.Left, s.mem()) + + case OPROC, ODEFER: + call := n.Left + fn := call.Left + if call.Op != OCALLFUNC { + s.Unimplementedf("defer/go of %s", opnames[call.Op]) + } + + // Write argsize and closure (args to Newproc/Deferproc) + argsize := s.constInt32(Types[TUINT32], int32(fn.Type.Argwid)) + s.vars[&memvar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, 4, s.sp, argsize, s.mem()) + closure := s.expr(fn) + addr := s.entryNewValue1I(ssa.OpOffPtr, Ptrto(Types[TUINTPTR]), int64(Widthptr), s.sp) + s.vars[&memvar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, int64(Widthptr), addr, closure, s.mem()) + + // Run all argument assignments. The arg slots have already + // been offset by 2*widthptr. + s.stmtList(call.List) + + // Call deferproc or newproc + bNext := s.f.NewBlock(ssa.BlockPlain) + var op ssa.Op + switch n.Op { + case ODEFER: + op = ssa.OpDeferCall + case OPROC: + op = ssa.OpGoCall + } + r := s.newValue1(op, ssa.TypeMem, s.mem()) + r.AuxInt = fn.Type.Argwid + 2*int64(Widthptr) // total stack space used + s.vars[&memvar] = r + b := s.endBlock() + b.Kind = ssa.BlockCall + b.Control = r + b.AddEdgeTo(bNext) + b.AddEdgeTo(s.exit) + s.startBlock(bNext) + + default: + s.Unimplementedf("unhandled stmt %s", opnames[n.Op]) + } +} + +type opAndType struct { + op uint8 + etype uint8 +} + +var opToSSA = map[opAndType]ssa.Op{ + opAndType{OADD, TINT8}: ssa.OpAdd8, + opAndType{OADD, TUINT8}: ssa.OpAdd8, + opAndType{OADD, TINT16}: ssa.OpAdd16, + opAndType{OADD, TUINT16}: ssa.OpAdd16, + opAndType{OADD, TINT32}: ssa.OpAdd32, + opAndType{OADD, TUINT32}: ssa.OpAdd32, + opAndType{OADD, TPTR32}: ssa.OpAdd32, + opAndType{OADD, TINT64}: ssa.OpAdd64, + opAndType{OADD, TUINT64}: ssa.OpAdd64, + opAndType{OADD, TPTR64}: ssa.OpAdd64, + opAndType{OADD, TFLOAT32}: ssa.OpAdd32F, + opAndType{OADD, TFLOAT64}: ssa.OpAdd64F, + + opAndType{OSUB, TINT8}: ssa.OpSub8, + opAndType{OSUB, TUINT8}: ssa.OpSub8, + opAndType{OSUB, TINT16}: ssa.OpSub16, + opAndType{OSUB, TUINT16}: ssa.OpSub16, + opAndType{OSUB, TINT32}: ssa.OpSub32, + opAndType{OSUB, TUINT32}: ssa.OpSub32, + opAndType{OSUB, TINT64}: ssa.OpSub64, + opAndType{OSUB, TUINT64}: ssa.OpSub64, + opAndType{OSUB, TFLOAT32}: ssa.OpSub32F, + opAndType{OSUB, TFLOAT64}: ssa.OpSub64F, + + opAndType{ONOT, TBOOL}: ssa.OpNot, + + opAndType{OMINUS, TINT8}: ssa.OpNeg8, + opAndType{OMINUS, TUINT8}: ssa.OpNeg8, + opAndType{OMINUS, TINT16}: ssa.OpNeg16, + opAndType{OMINUS, TUINT16}: ssa.OpNeg16, + opAndType{OMINUS, TINT32}: ssa.OpNeg32, + opAndType{OMINUS, TUINT32}: ssa.OpNeg32, + opAndType{OMINUS, TINT64}: ssa.OpNeg64, + opAndType{OMINUS, TUINT64}: ssa.OpNeg64, + opAndType{OMINUS, TFLOAT32}: ssa.OpNeg32F, + opAndType{OMINUS, TFLOAT64}: ssa.OpNeg64F, + + opAndType{OCOM, TINT8}: ssa.OpCom8, + opAndType{OCOM, TUINT8}: ssa.OpCom8, + opAndType{OCOM, TINT16}: ssa.OpCom16, + opAndType{OCOM, TUINT16}: ssa.OpCom16, + opAndType{OCOM, TINT32}: ssa.OpCom32, + opAndType{OCOM, TUINT32}: ssa.OpCom32, + opAndType{OCOM, TINT64}: ssa.OpCom64, + opAndType{OCOM, TUINT64}: ssa.OpCom64, + + opAndType{OIMAG, TCOMPLEX64}: ssa.OpComplexImag, + opAndType{OIMAG, TCOMPLEX128}: ssa.OpComplexImag, + opAndType{OREAL, TCOMPLEX64}: ssa.OpComplexReal, + opAndType{OREAL, TCOMPLEX128}: ssa.OpComplexReal, + + opAndType{OMUL, TINT8}: ssa.OpMul8, + opAndType{OMUL, TUINT8}: ssa.OpMul8, + opAndType{OMUL, TINT16}: ssa.OpMul16, + opAndType{OMUL, TUINT16}: ssa.OpMul16, + opAndType{OMUL, TINT32}: ssa.OpMul32, + opAndType{OMUL, TUINT32}: ssa.OpMul32, + opAndType{OMUL, TINT64}: ssa.OpMul64, + opAndType{OMUL, TUINT64}: ssa.OpMul64, + opAndType{OMUL, TFLOAT32}: ssa.OpMul32F, + opAndType{OMUL, TFLOAT64}: ssa.OpMul64F, + + opAndType{ODIV, TFLOAT32}: ssa.OpDiv32F, + opAndType{ODIV, TFLOAT64}: ssa.OpDiv64F, + + opAndType{OHMUL, TINT8}: ssa.OpHmul8, + opAndType{OHMUL, TUINT8}: ssa.OpHmul8u, + opAndType{OHMUL, TINT16}: ssa.OpHmul16, + opAndType{OHMUL, TUINT16}: ssa.OpHmul16u, + opAndType{OHMUL, TINT32}: ssa.OpHmul32, + opAndType{OHMUL, TUINT32}: ssa.OpHmul32u, + + opAndType{ODIV, TINT8}: ssa.OpDiv8, + opAndType{ODIV, TUINT8}: ssa.OpDiv8u, + opAndType{ODIV, TINT16}: ssa.OpDiv16, + opAndType{ODIV, TUINT16}: ssa.OpDiv16u, + opAndType{ODIV, TINT32}: ssa.OpDiv32, + opAndType{ODIV, TUINT32}: ssa.OpDiv32u, + opAndType{ODIV, TINT64}: ssa.OpDiv64, + opAndType{ODIV, TUINT64}: ssa.OpDiv64u, + + opAndType{OMOD, TINT8}: ssa.OpMod8, + opAndType{OMOD, TUINT8}: ssa.OpMod8u, + opAndType{OMOD, TINT16}: ssa.OpMod16, + opAndType{OMOD, TUINT16}: ssa.OpMod16u, + opAndType{OMOD, TINT32}: ssa.OpMod32, + opAndType{OMOD, TUINT32}: ssa.OpMod32u, + opAndType{OMOD, TINT64}: ssa.OpMod64, + opAndType{OMOD, TUINT64}: ssa.OpMod64u, + + opAndType{OAND, TINT8}: ssa.OpAnd8, + opAndType{OAND, TUINT8}: ssa.OpAnd8, + opAndType{OAND, TINT16}: ssa.OpAnd16, + opAndType{OAND, TUINT16}: ssa.OpAnd16, + opAndType{OAND, TINT32}: ssa.OpAnd32, + opAndType{OAND, TUINT32}: ssa.OpAnd32, + opAndType{OAND, TINT64}: ssa.OpAnd64, + opAndType{OAND, TUINT64}: ssa.OpAnd64, + + opAndType{OOR, TINT8}: ssa.OpOr8, + opAndType{OOR, TUINT8}: ssa.OpOr8, + opAndType{OOR, TINT16}: ssa.OpOr16, + opAndType{OOR, TUINT16}: ssa.OpOr16, + opAndType{OOR, TINT32}: ssa.OpOr32, + opAndType{OOR, TUINT32}: ssa.OpOr32, + opAndType{OOR, TINT64}: ssa.OpOr64, + opAndType{OOR, TUINT64}: ssa.OpOr64, + + opAndType{OXOR, TINT8}: ssa.OpXor8, + opAndType{OXOR, TUINT8}: ssa.OpXor8, + opAndType{OXOR, TINT16}: ssa.OpXor16, + opAndType{OXOR, TUINT16}: ssa.OpXor16, + opAndType{OXOR, TINT32}: ssa.OpXor32, + opAndType{OXOR, TUINT32}: ssa.OpXor32, + opAndType{OXOR, TINT64}: ssa.OpXor64, + opAndType{OXOR, TUINT64}: ssa.OpXor64, + + opAndType{OEQ, TBOOL}: ssa.OpEq8, + opAndType{OEQ, TINT8}: ssa.OpEq8, + opAndType{OEQ, TUINT8}: ssa.OpEq8, + opAndType{OEQ, TINT16}: ssa.OpEq16, + opAndType{OEQ, TUINT16}: ssa.OpEq16, + opAndType{OEQ, TINT32}: ssa.OpEq32, + opAndType{OEQ, TUINT32}: ssa.OpEq32, + opAndType{OEQ, TINT64}: ssa.OpEq64, + opAndType{OEQ, TUINT64}: ssa.OpEq64, + opAndType{OEQ, TINTER}: ssa.OpEqFat, // e == nil only + opAndType{OEQ, TARRAY}: ssa.OpEqFat, // slice only; a == nil only + opAndType{OEQ, TFUNC}: ssa.OpEqPtr, + opAndType{OEQ, TMAP}: ssa.OpEqPtr, + opAndType{OEQ, TCHAN}: ssa.OpEqPtr, + opAndType{OEQ, TPTR64}: ssa.OpEqPtr, + opAndType{OEQ, TUINTPTR}: ssa.OpEqPtr, + opAndType{OEQ, TUNSAFEPTR}: ssa.OpEqPtr, + opAndType{OEQ, TFLOAT64}: ssa.OpEq64F, + opAndType{OEQ, TFLOAT32}: ssa.OpEq32F, + + opAndType{ONE, TBOOL}: ssa.OpNeq8, + opAndType{ONE, TINT8}: ssa.OpNeq8, + opAndType{ONE, TUINT8}: ssa.OpNeq8, + opAndType{ONE, TINT16}: ssa.OpNeq16, + opAndType{ONE, TUINT16}: ssa.OpNeq16, + opAndType{ONE, TINT32}: ssa.OpNeq32, + opAndType{ONE, TUINT32}: ssa.OpNeq32, + opAndType{ONE, TINT64}: ssa.OpNeq64, + opAndType{ONE, TUINT64}: ssa.OpNeq64, + opAndType{ONE, TINTER}: ssa.OpNeqFat, // e != nil only + opAndType{ONE, TARRAY}: ssa.OpNeqFat, // slice only; a != nil only + opAndType{ONE, TFUNC}: ssa.OpNeqPtr, + opAndType{ONE, TMAP}: ssa.OpNeqPtr, + opAndType{ONE, TCHAN}: ssa.OpNeqPtr, + opAndType{ONE, TPTR64}: ssa.OpNeqPtr, + opAndType{ONE, TUINTPTR}: ssa.OpNeqPtr, + opAndType{ONE, TUNSAFEPTR}: ssa.OpNeqPtr, + opAndType{ONE, TFLOAT64}: ssa.OpNeq64F, + opAndType{ONE, TFLOAT32}: ssa.OpNeq32F, + + opAndType{OLT, TINT8}: ssa.OpLess8, + opAndType{OLT, TUINT8}: ssa.OpLess8U, + opAndType{OLT, TINT16}: ssa.OpLess16, + opAndType{OLT, TUINT16}: ssa.OpLess16U, + opAndType{OLT, TINT32}: ssa.OpLess32, + opAndType{OLT, TUINT32}: ssa.OpLess32U, + opAndType{OLT, TINT64}: ssa.OpLess64, + opAndType{OLT, TUINT64}: ssa.OpLess64U, + opAndType{OLT, TFLOAT64}: ssa.OpLess64F, + opAndType{OLT, TFLOAT32}: ssa.OpLess32F, + + opAndType{OGT, TINT8}: ssa.OpGreater8, + opAndType{OGT, TUINT8}: ssa.OpGreater8U, + opAndType{OGT, TINT16}: ssa.OpGreater16, + opAndType{OGT, TUINT16}: ssa.OpGreater16U, + opAndType{OGT, TINT32}: ssa.OpGreater32, + opAndType{OGT, TUINT32}: ssa.OpGreater32U, + opAndType{OGT, TINT64}: ssa.OpGreater64, + opAndType{OGT, TUINT64}: ssa.OpGreater64U, + opAndType{OGT, TFLOAT64}: ssa.OpGreater64F, + opAndType{OGT, TFLOAT32}: ssa.OpGreater32F, + + opAndType{OLE, TINT8}: ssa.OpLeq8, + opAndType{OLE, TUINT8}: ssa.OpLeq8U, + opAndType{OLE, TINT16}: ssa.OpLeq16, + opAndType{OLE, TUINT16}: ssa.OpLeq16U, + opAndType{OLE, TINT32}: ssa.OpLeq32, + opAndType{OLE, TUINT32}: ssa.OpLeq32U, + opAndType{OLE, TINT64}: ssa.OpLeq64, + opAndType{OLE, TUINT64}: ssa.OpLeq64U, + opAndType{OLE, TFLOAT64}: ssa.OpLeq64F, + opAndType{OLE, TFLOAT32}: ssa.OpLeq32F, + + opAndType{OGE, TINT8}: ssa.OpGeq8, + opAndType{OGE, TUINT8}: ssa.OpGeq8U, + opAndType{OGE, TINT16}: ssa.OpGeq16, + opAndType{OGE, TUINT16}: ssa.OpGeq16U, + opAndType{OGE, TINT32}: ssa.OpGeq32, + opAndType{OGE, TUINT32}: ssa.OpGeq32U, + opAndType{OGE, TINT64}: ssa.OpGeq64, + opAndType{OGE, TUINT64}: ssa.OpGeq64U, + opAndType{OGE, TFLOAT64}: ssa.OpGeq64F, + opAndType{OGE, TFLOAT32}: ssa.OpGeq32F, + + opAndType{OLROT, TUINT8}: ssa.OpLrot8, + opAndType{OLROT, TUINT16}: ssa.OpLrot16, + opAndType{OLROT, TUINT32}: ssa.OpLrot32, + opAndType{OLROT, TUINT64}: ssa.OpLrot64, +} + +func (s *state) concreteEtype(t *Type) uint8 { + e := t.Etype + switch e { + default: + return e + case TINT: + if s.config.IntSize == 8 { + return TINT64 + } + return TINT32 + case TUINT: + if s.config.IntSize == 8 { + return TUINT64 + } + return TUINT32 + case TUINTPTR: + if s.config.PtrSize == 8 { + return TUINT64 + } + return TUINT32 + } +} + +func (s *state) ssaOp(op uint8, t *Type) ssa.Op { + etype := s.concreteEtype(t) + x, ok := opToSSA[opAndType{op, etype}] + if !ok { + s.Unimplementedf("unhandled binary op %s %s", opnames[op], Econv(int(etype), 0)) + } + return x +} + +func floatForComplex(t *Type) *Type { + if t.Size() == 8 { + return Types[TFLOAT32] + } else { + return Types[TFLOAT64] + } +} + +type opAndTwoTypes struct { + op uint8 + etype1 uint8 + etype2 uint8 +} + +type twoTypes struct { + etype1 uint8 + etype2 uint8 +} + +type twoOpsAndType struct { + op1 ssa.Op + op2 ssa.Op + intermediateType uint8 +} + +var fpConvOpToSSA = map[twoTypes]twoOpsAndType{ + + twoTypes{TINT8, TFLOAT32}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to32F, TINT32}, + twoTypes{TINT16, TFLOAT32}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to32F, TINT32}, + twoTypes{TINT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to32F, TINT32}, + twoTypes{TINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to32F, TINT64}, + + twoTypes{TINT8, TFLOAT64}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to64F, TINT32}, + twoTypes{TINT16, TFLOAT64}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to64F, TINT32}, + twoTypes{TINT32, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to64F, TINT32}, + twoTypes{TINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to64F, TINT64}, + + twoTypes{TFLOAT32, TINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32}, + twoTypes{TFLOAT32, TINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32}, + twoTypes{TFLOAT32, TINT32}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpCopy, TINT32}, + twoTypes{TFLOAT32, TINT64}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpCopy, TINT64}, + + twoTypes{TFLOAT64, TINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32}, + twoTypes{TFLOAT64, TINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32}, + twoTypes{TFLOAT64, TINT32}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpCopy, TINT32}, + twoTypes{TFLOAT64, TINT64}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpCopy, TINT64}, + // unsigned + twoTypes{TUINT8, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to32F, TINT32}, + twoTypes{TUINT16, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to32F, TINT32}, + twoTypes{TUINT32, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to32F, TINT64}, // go wide to dodge unsigned + twoTypes{TUINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto32F, branchy code expansion instead + + twoTypes{TUINT8, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to64F, TINT32}, + twoTypes{TUINT16, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to64F, TINT32}, + twoTypes{TUINT32, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to64F, TINT64}, // go wide to dodge unsigned + twoTypes{TUINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto64F, branchy code expansion instead + + twoTypes{TFLOAT32, TUINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32}, + twoTypes{TFLOAT32, TUINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32}, + twoTypes{TFLOAT32, TUINT32}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned + twoTypes{TFLOAT32, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt32Fto64U, branchy code expansion instead + + twoTypes{TFLOAT64, TUINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32}, + twoTypes{TFLOAT64, TUINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32}, + twoTypes{TFLOAT64, TUINT32}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned + twoTypes{TFLOAT64, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt64Fto64U, branchy code expansion instead + + // float + twoTypes{TFLOAT64, TFLOAT32}: twoOpsAndType{ssa.OpCvt64Fto32F, ssa.OpCopy, TFLOAT32}, + twoTypes{TFLOAT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCopy, TFLOAT64}, + twoTypes{TFLOAT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCopy, TFLOAT32}, + twoTypes{TFLOAT32, TFLOAT64}: twoOpsAndType{ssa.OpCvt32Fto64F, ssa.OpCopy, TFLOAT64}, +} + +var shiftOpToSSA = map[opAndTwoTypes]ssa.Op{ + opAndTwoTypes{OLSH, TINT8, TUINT8}: ssa.OpLsh8x8, + opAndTwoTypes{OLSH, TUINT8, TUINT8}: ssa.OpLsh8x8, + opAndTwoTypes{OLSH, TINT8, TUINT16}: ssa.OpLsh8x16, + opAndTwoTypes{OLSH, TUINT8, TUINT16}: ssa.OpLsh8x16, + opAndTwoTypes{OLSH, TINT8, TUINT32}: ssa.OpLsh8x32, + opAndTwoTypes{OLSH, TUINT8, TUINT32}: ssa.OpLsh8x32, + opAndTwoTypes{OLSH, TINT8, TUINT64}: ssa.OpLsh8x64, + opAndTwoTypes{OLSH, TUINT8, TUINT64}: ssa.OpLsh8x64, + + opAndTwoTypes{OLSH, TINT16, TUINT8}: ssa.OpLsh16x8, + opAndTwoTypes{OLSH, TUINT16, TUINT8}: ssa.OpLsh16x8, + opAndTwoTypes{OLSH, TINT16, TUINT16}: ssa.OpLsh16x16, + opAndTwoTypes{OLSH, TUINT16, TUINT16}: ssa.OpLsh16x16, + opAndTwoTypes{OLSH, TINT16, TUINT32}: ssa.OpLsh16x32, + opAndTwoTypes{OLSH, TUINT16, TUINT32}: ssa.OpLsh16x32, + opAndTwoTypes{OLSH, TINT16, TUINT64}: ssa.OpLsh16x64, + opAndTwoTypes{OLSH, TUINT16, TUINT64}: ssa.OpLsh16x64, + + opAndTwoTypes{OLSH, TINT32, TUINT8}: ssa.OpLsh32x8, + opAndTwoTypes{OLSH, TUINT32, TUINT8}: ssa.OpLsh32x8, + opAndTwoTypes{OLSH, TINT32, TUINT16}: ssa.OpLsh32x16, + opAndTwoTypes{OLSH, TUINT32, TUINT16}: ssa.OpLsh32x16, + opAndTwoTypes{OLSH, TINT32, TUINT32}: ssa.OpLsh32x32, + opAndTwoTypes{OLSH, TUINT32, TUINT32}: ssa.OpLsh32x32, + opAndTwoTypes{OLSH, TINT32, TUINT64}: ssa.OpLsh32x64, + opAndTwoTypes{OLSH, TUINT32, TUINT64}: ssa.OpLsh32x64, + + opAndTwoTypes{OLSH, TINT64, TUINT8}: ssa.OpLsh64x8, + opAndTwoTypes{OLSH, TUINT64, TUINT8}: ssa.OpLsh64x8, + opAndTwoTypes{OLSH, TINT64, TUINT16}: ssa.OpLsh64x16, + opAndTwoTypes{OLSH, TUINT64, TUINT16}: ssa.OpLsh64x16, + opAndTwoTypes{OLSH, TINT64, TUINT32}: ssa.OpLsh64x32, + opAndTwoTypes{OLSH, TUINT64, TUINT32}: ssa.OpLsh64x32, + opAndTwoTypes{OLSH, TINT64, TUINT64}: ssa.OpLsh64x64, + opAndTwoTypes{OLSH, TUINT64, TUINT64}: ssa.OpLsh64x64, + + opAndTwoTypes{ORSH, TINT8, TUINT8}: ssa.OpRsh8x8, + opAndTwoTypes{ORSH, TUINT8, TUINT8}: ssa.OpRsh8Ux8, + opAndTwoTypes{ORSH, TINT8, TUINT16}: ssa.OpRsh8x16, + opAndTwoTypes{ORSH, TUINT8, TUINT16}: ssa.OpRsh8Ux16, + opAndTwoTypes{ORSH, TINT8, TUINT32}: ssa.OpRsh8x32, + opAndTwoTypes{ORSH, TUINT8, TUINT32}: ssa.OpRsh8Ux32, + opAndTwoTypes{ORSH, TINT8, TUINT64}: ssa.OpRsh8x64, + opAndTwoTypes{ORSH, TUINT8, TUINT64}: ssa.OpRsh8Ux64, + + opAndTwoTypes{ORSH, TINT16, TUINT8}: ssa.OpRsh16x8, + opAndTwoTypes{ORSH, TUINT16, TUINT8}: ssa.OpRsh16Ux8, + opAndTwoTypes{ORSH, TINT16, TUINT16}: ssa.OpRsh16x16, + opAndTwoTypes{ORSH, TUINT16, TUINT16}: ssa.OpRsh16Ux16, + opAndTwoTypes{ORSH, TINT16, TUINT32}: ssa.OpRsh16x32, + opAndTwoTypes{ORSH, TUINT16, TUINT32}: ssa.OpRsh16Ux32, + opAndTwoTypes{ORSH, TINT16, TUINT64}: ssa.OpRsh16x64, + opAndTwoTypes{ORSH, TUINT16, TUINT64}: ssa.OpRsh16Ux64, + + opAndTwoTypes{ORSH, TINT32, TUINT8}: ssa.OpRsh32x8, + opAndTwoTypes{ORSH, TUINT32, TUINT8}: ssa.OpRsh32Ux8, + opAndTwoTypes{ORSH, TINT32, TUINT16}: ssa.OpRsh32x16, + opAndTwoTypes{ORSH, TUINT32, TUINT16}: ssa.OpRsh32Ux16, + opAndTwoTypes{ORSH, TINT32, TUINT32}: ssa.OpRsh32x32, + opAndTwoTypes{ORSH, TUINT32, TUINT32}: ssa.OpRsh32Ux32, + opAndTwoTypes{ORSH, TINT32, TUINT64}: ssa.OpRsh32x64, + opAndTwoTypes{ORSH, TUINT32, TUINT64}: ssa.OpRsh32Ux64, + + opAndTwoTypes{ORSH, TINT64, TUINT8}: ssa.OpRsh64x8, + opAndTwoTypes{ORSH, TUINT64, TUINT8}: ssa.OpRsh64Ux8, + opAndTwoTypes{ORSH, TINT64, TUINT16}: ssa.OpRsh64x16, + opAndTwoTypes{ORSH, TUINT64, TUINT16}: ssa.OpRsh64Ux16, + opAndTwoTypes{ORSH, TINT64, TUINT32}: ssa.OpRsh64x32, + opAndTwoTypes{ORSH, TUINT64, TUINT32}: ssa.OpRsh64Ux32, + opAndTwoTypes{ORSH, TINT64, TUINT64}: ssa.OpRsh64x64, + opAndTwoTypes{ORSH, TUINT64, TUINT64}: ssa.OpRsh64Ux64, +} + +func (s *state) ssaShiftOp(op uint8, t *Type, u *Type) ssa.Op { + etype1 := s.concreteEtype(t) + etype2 := s.concreteEtype(u) + x, ok := shiftOpToSSA[opAndTwoTypes{op, etype1, etype2}] + if !ok { + s.Unimplementedf("unhandled shift op %s etype=%s/%s", opnames[op], Econv(int(etype1), 0), Econv(int(etype2), 0)) + } + return x +} + +func (s *state) ssaRotateOp(op uint8, t *Type) ssa.Op { + etype1 := s.concreteEtype(t) + x, ok := opToSSA[opAndType{op, etype1}] + if !ok { + s.Unimplementedf("unhandled rotate op %s etype=%s", opnames[op], Econv(int(etype1), 0)) + } + return x +} + +// expr converts the expression n to ssa, adds it to s and returns the ssa result. +func (s *state) expr(n *Node) *ssa.Value { + s.pushLine(n.Lineno) + defer s.popLine() + + s.stmtList(n.Ninit) + switch n.Op { + case ONAME: + if n.Class == PFUNC { + // "value" of a function is the address of the function's closure + sym := funcsym(n.Sym) + aux := &ssa.ExternSymbol{n.Type, sym} + return s.entryNewValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sb) + } + if canSSA(n) { + return s.variable(n, n.Type) + } + addr := s.addr(n) + return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem()) + case OLITERAL: + switch n.Val().Ctype() { + case CTINT: + i := Mpgetfix(n.Val().U.(*Mpint)) + switch n.Type.Size() { + case 1: + return s.constInt8(n.Type, int8(i)) + case 2: + return s.constInt16(n.Type, int16(i)) + case 4: + return s.constInt32(n.Type, int32(i)) + case 8: + return s.constInt64(n.Type, i) + default: + s.Fatalf("bad integer size %d", n.Type.Size()) + return nil + } + case CTSTR: + return s.entryNewValue0A(ssa.OpConstString, n.Type, n.Val().U) + case CTBOOL: + if n.Val().U.(bool) { + return s.entryNewValue0I(ssa.OpConstBool, Types[TBOOL], 1) // 1 = true + } else { + return s.entryNewValue0I(ssa.OpConstBool, Types[TBOOL], 0) // 0 = false + } + case CTNIL: + t := n.Type + switch { + case t.IsSlice(): + return s.entryNewValue0(ssa.OpConstSlice, t) + case t.IsInterface(): + return s.entryNewValue0(ssa.OpConstInterface, t) + default: + return s.entryNewValue0(ssa.OpConstNil, t) + } + case CTFLT: + f := n.Val().U.(*Mpflt) + switch n.Type.Size() { + case 4: + return s.constFloat32(n.Type, mpgetflt32(f)) + case 8: + return s.constFloat64(n.Type, mpgetflt(f)) + default: + s.Fatalf("bad float size %d", n.Type.Size()) + return nil + } + case CTCPLX: + c := n.Val().U.(*Mpcplx) + r := &c.Real + i := &c.Imag + switch n.Type.Size() { + case 8: + { + pt := Types[TFLOAT32] + return s.newValue2(ssa.OpComplexMake, n.Type, + s.constFloat32(pt, mpgetflt32(r)), + s.constFloat32(pt, mpgetflt32(i))) + } + case 16: + { + pt := Types[TFLOAT64] + return s.newValue2(ssa.OpComplexMake, n.Type, + s.constFloat64(pt, mpgetflt(r)), + s.constFloat64(pt, mpgetflt(i))) + } + default: + s.Fatalf("bad float size %d", n.Type.Size()) + return nil + } + + default: + s.Unimplementedf("unhandled OLITERAL %v", n.Val().Ctype()) + return nil + } + case OCONVNOP: + to := n.Type + from := n.Left.Type + if to.Etype == TFUNC { + s.Unimplementedf("CONVNOP closure") + return nil + } + + // Assume everything will work out, so set up our return value. + // Anything interesting that happens from here is a fatal. + x := s.expr(n.Left) + v := s.newValue1(ssa.OpCopy, to, x) // ensure that v has the right type + + // named <--> unnamed type or typed <--> untyped const + if from.Etype == to.Etype { + return v + } + // unsafe.Pointer <--> *T + if to.Etype == TUNSAFEPTR && from.IsPtr() || from.Etype == TUNSAFEPTR && to.IsPtr() { + return v + } + + dowidth(from) + dowidth(to) + if from.Width != to.Width { + s.Fatalf("CONVNOP width mismatch %v (%d) -> %v (%d)\n", from, from.Width, to, to.Width) + return nil + } + if etypesign(from.Etype) != etypesign(to.Etype) { + s.Fatalf("CONVNOP sign mismatch %v (%s) -> %v (%s)\n", from, Econv(int(from.Etype), 0), to, Econv(int(to.Etype), 0)) + return nil + } + + if flag_race != 0 { + s.Unimplementedf("questionable CONVNOP from race detector %v -> %v\n", from, to) + return nil + } + + if etypesign(from.Etype) == 0 { + s.Fatalf("CONVNOP unrecognized non-integer %v -> %v\n", from, to) + return nil + } + + // integer, same width, same sign + return v + + case OCONV: + x := s.expr(n.Left) + ft := n.Left.Type // from type + tt := n.Type // to type + if ft.IsInteger() && tt.IsInteger() { + var op ssa.Op + if tt.Size() == ft.Size() { + op = ssa.OpCopy + } else if tt.Size() < ft.Size() { + // truncation + switch 10*ft.Size() + tt.Size() { + case 21: + op = ssa.OpTrunc16to8 + case 41: + op = ssa.OpTrunc32to8 + case 42: + op = ssa.OpTrunc32to16 + case 81: + op = ssa.OpTrunc64to8 + case 82: + op = ssa.OpTrunc64to16 + case 84: + op = ssa.OpTrunc64to32 + default: + s.Fatalf("weird integer truncation %s -> %s", ft, tt) + } + } else if ft.IsSigned() { + // sign extension + switch 10*ft.Size() + tt.Size() { + case 12: + op = ssa.OpSignExt8to16 + case 14: + op = ssa.OpSignExt8to32 + case 18: + op = ssa.OpSignExt8to64 + case 24: + op = ssa.OpSignExt16to32 + case 28: + op = ssa.OpSignExt16to64 + case 48: + op = ssa.OpSignExt32to64 + default: + s.Fatalf("bad integer sign extension %s -> %s", ft, tt) + } + } else { + // zero extension + switch 10*ft.Size() + tt.Size() { + case 12: + op = ssa.OpZeroExt8to16 + case 14: + op = ssa.OpZeroExt8to32 + case 18: + op = ssa.OpZeroExt8to64 + case 24: + op = ssa.OpZeroExt16to32 + case 28: + op = ssa.OpZeroExt16to64 + case 48: + op = ssa.OpZeroExt32to64 + default: + s.Fatalf("weird integer sign extension %s -> %s", ft, tt) + } + } + return s.newValue1(op, n.Type, x) + } + + if ft.IsFloat() || tt.IsFloat() { + conv, ok := fpConvOpToSSA[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}] + if !ok { + s.Fatalf("weird float conversion %s -> %s", ft, tt) + } + op1, op2, it := conv.op1, conv.op2, conv.intermediateType + + if op1 != ssa.OpInvalid && op2 != ssa.OpInvalid { + // normal case, not tripping over unsigned 64 + if op1 == ssa.OpCopy { + if op2 == ssa.OpCopy { + return x + } + return s.newValue1(op2, n.Type, x) + } + if op2 == ssa.OpCopy { + return s.newValue1(op1, n.Type, x) + } + return s.newValue1(op2, n.Type, s.newValue1(op1, Types[it], x)) + } + // Tricky 64-bit unsigned cases. + if ft.IsInteger() { + // therefore tt is float32 or float64, and ft is also unsigned + if tt.Size() == 4 { + return s.uint64Tofloat32(n, x, ft, tt) + } + if tt.Size() == 8 { + return s.uint64Tofloat64(n, x, ft, tt) + } + s.Fatalf("weird unsigned integer to float conversion %s -> %s", ft, tt) + } + // therefore ft is float32 or float64, and tt is unsigned integer + if ft.Size() == 4 { + return s.float32ToUint64(n, x, ft, tt) + } + if ft.Size() == 8 { + return s.float64ToUint64(n, x, ft, tt) + } + s.Fatalf("weird float to unsigned integer conversion %s -> %s", ft, tt) + return nil + } + + if ft.IsComplex() && tt.IsComplex() { + var op ssa.Op + if ft.Size() == tt.Size() { + op = ssa.OpCopy + } else if ft.Size() == 8 && tt.Size() == 16 { + op = ssa.OpCvt32Fto64F + } else if ft.Size() == 16 && tt.Size() == 8 { + op = ssa.OpCvt64Fto32F + } else { + s.Fatalf("weird complex conversion %s -> %s", ft, tt) + } + ftp := floatForComplex(ft) + ttp := floatForComplex(tt) + return s.newValue2(ssa.OpComplexMake, tt, + s.newValue1(op, ttp, s.newValue1(ssa.OpComplexReal, ftp, x)), + s.newValue1(op, ttp, s.newValue1(ssa.OpComplexImag, ftp, x))) + } + + s.Unimplementedf("unhandled OCONV %s -> %s", Econv(int(n.Left.Type.Etype), 0), Econv(int(n.Type.Etype), 0)) + return nil + + // binary ops + case OLT, OEQ, ONE, OLE, OGE, OGT: + a := s.expr(n.Left) + b := s.expr(n.Right) + return s.newValue2(s.ssaOp(n.Op, n.Left.Type), Types[TBOOL], a, b) + case OMUL: + a := s.expr(n.Left) + b := s.expr(n.Right) + if n.Type.IsComplex() { + mulop := ssa.OpMul64F + addop := ssa.OpAdd64F + subop := ssa.OpSub64F + pt := floatForComplex(n.Type) // Could be Float32 or Float64 + wt := Types[TFLOAT64] // Compute in Float64 to minimize cancellation error + + areal := s.newValue1(ssa.OpComplexReal, pt, a) + breal := s.newValue1(ssa.OpComplexReal, pt, b) + aimag := s.newValue1(ssa.OpComplexImag, pt, a) + bimag := s.newValue1(ssa.OpComplexImag, pt, b) + + if pt != wt { // Widen for calculation + areal = s.newValue1(ssa.OpCvt32Fto64F, wt, areal) + breal = s.newValue1(ssa.OpCvt32Fto64F, wt, breal) + aimag = s.newValue1(ssa.OpCvt32Fto64F, wt, aimag) + bimag = s.newValue1(ssa.OpCvt32Fto64F, wt, bimag) + } + + xreal := s.newValue2(subop, wt, s.newValue2(mulop, wt, areal, breal), s.newValue2(mulop, wt, aimag, bimag)) + ximag := s.newValue2(addop, wt, s.newValue2(mulop, wt, areal, bimag), s.newValue2(mulop, wt, aimag, breal)) + + if pt != wt { // Narrow to store back + xreal = s.newValue1(ssa.OpCvt64Fto32F, pt, xreal) + ximag = s.newValue1(ssa.OpCvt64Fto32F, pt, ximag) + } + + return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag) + } + return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b) + + case ODIV: + a := s.expr(n.Left) + b := s.expr(n.Right) + if n.Type.IsComplex() { + // TODO this is not executed because the front-end substitutes a runtime call. + // That probably ought to change; with modest optimization the widen/narrow + // conversions could all be elided in larger expression trees. + mulop := ssa.OpMul64F + addop := ssa.OpAdd64F + subop := ssa.OpSub64F + divop := ssa.OpDiv64F + pt := floatForComplex(n.Type) // Could be Float32 or Float64 + wt := Types[TFLOAT64] // Compute in Float64 to minimize cancellation error + + areal := s.newValue1(ssa.OpComplexReal, pt, a) + breal := s.newValue1(ssa.OpComplexReal, pt, b) + aimag := s.newValue1(ssa.OpComplexImag, pt, a) + bimag := s.newValue1(ssa.OpComplexImag, pt, b) + + if pt != wt { // Widen for calculation + areal = s.newValue1(ssa.OpCvt32Fto64F, wt, areal) + breal = s.newValue1(ssa.OpCvt32Fto64F, wt, breal) + aimag = s.newValue1(ssa.OpCvt32Fto64F, wt, aimag) + bimag = s.newValue1(ssa.OpCvt32Fto64F, wt, bimag) + } + + denom := s.newValue2(addop, wt, s.newValue2(mulop, wt, breal, breal), s.newValue2(mulop, wt, bimag, bimag)) + xreal := s.newValue2(addop, wt, s.newValue2(mulop, wt, areal, breal), s.newValue2(mulop, wt, aimag, bimag)) + ximag := s.newValue2(subop, wt, s.newValue2(mulop, wt, aimag, breal), s.newValue2(mulop, wt, areal, bimag)) + + // TODO not sure if this is best done in wide precision or narrow + // Double-rounding might be an issue. + // Note that the pre-SSA implementation does the entire calculation + // in wide format, so wide is compatible. + xreal = s.newValue2(divop, wt, xreal, denom) + ximag = s.newValue2(divop, wt, ximag, denom) + + if pt != wt { // Narrow to store back + xreal = s.newValue1(ssa.OpCvt64Fto32F, pt, xreal) + ximag = s.newValue1(ssa.OpCvt64Fto32F, pt, ximag) + } + + return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag) + } + return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b) + case OADD, OSUB: + a := s.expr(n.Left) + b := s.expr(n.Right) + if n.Type.IsComplex() { + pt := floatForComplex(n.Type) + op := s.ssaOp(n.Op, pt) + return s.newValue2(ssa.OpComplexMake, n.Type, + s.newValue2(op, pt, s.newValue1(ssa.OpComplexReal, pt, a), s.newValue1(ssa.OpComplexReal, pt, b)), + s.newValue2(op, pt, s.newValue1(ssa.OpComplexImag, pt, a), s.newValue1(ssa.OpComplexImag, pt, b))) + } + return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b) + case OAND, OOR, OMOD, OHMUL, OXOR: + a := s.expr(n.Left) + b := s.expr(n.Right) + return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b) + case OLSH, ORSH: + a := s.expr(n.Left) + b := s.expr(n.Right) + return s.newValue2(s.ssaShiftOp(n.Op, n.Type, n.Right.Type), a.Type, a, b) + case OLROT: + a := s.expr(n.Left) + i := n.Right.Int() + if i <= 0 || i >= n.Type.Size()*8 { + s.Fatalf("Wrong rotate distance for LROT, expected 1 through %d, saw %d", n.Type.Size()*8-1, i) + } + return s.newValue1I(s.ssaRotateOp(n.Op, n.Type), a.Type, i, a) + case OANDAND, OOROR: + // To implement OANDAND (and OOROR), we introduce a + // new temporary variable to hold the result. The + // variable is associated with the OANDAND node in the + // s.vars table (normally variables are only + // associated with ONAME nodes). We convert + // A && B + // to + // var = A + // if var { + // var = B + // } + // Using var in the subsequent block introduces the + // necessary phi variable. + el := s.expr(n.Left) + s.vars[n] = el + + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Control = el + // In theory, we should set b.Likely here based on context. + // However, gc only gives us likeliness hints + // in a single place, for plain OIF statements, + // and passing around context is finnicky, so don't bother for now. + + bRight := s.f.NewBlock(ssa.BlockPlain) + bResult := s.f.NewBlock(ssa.BlockPlain) + if n.Op == OANDAND { + b.AddEdgeTo(bRight) + b.AddEdgeTo(bResult) + } else if n.Op == OOROR { + b.AddEdgeTo(bResult) + b.AddEdgeTo(bRight) + } + + s.startBlock(bRight) + er := s.expr(n.Right) + s.vars[n] = er + + b = s.endBlock() + b.AddEdgeTo(bResult) + + s.startBlock(bResult) + return s.variable(n, Types[TBOOL]) + + // unary ops + case OMINUS: + a := s.expr(n.Left) + if n.Type.IsComplex() { + tp := floatForComplex(n.Type) + negop := s.ssaOp(n.Op, tp) + return s.newValue2(ssa.OpComplexMake, n.Type, + s.newValue1(negop, tp, s.newValue1(ssa.OpComplexReal, tp, a)), + s.newValue1(negop, tp, s.newValue1(ssa.OpComplexImag, tp, a))) + } + return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a) + case ONOT, OCOM, OIMAG, OREAL: + a := s.expr(n.Left) + return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a) + case OPLUS: + return s.expr(n.Left) + + case OADDR: + return s.addr(n.Left) + + case OCHECKNIL: + p := s.expr(n.Left) + s.nilCheck(p) + return p + + case OINDREG: + if int(n.Reg) != Thearch.REGSP { + s.Unimplementedf("OINDREG of non-SP register %s in expr: %v", obj.Rconv(int(n.Reg)), n) + return nil + } + addr := s.entryNewValue1I(ssa.OpOffPtr, Ptrto(n.Type), n.Xoffset, s.sp) + return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem()) + + case OIND: + p := s.expr(n.Left) + s.nilCheck(p) + return s.newValue2(ssa.OpLoad, n.Type, p, s.mem()) + + case ODOT: + v := s.expr(n.Left) + return s.newValue1I(ssa.OpStructSelect, n.Type, n.Xoffset, v) + + case ODOTPTR: + p := s.expr(n.Left) + s.nilCheck(p) + p = s.newValue2(ssa.OpAddPtr, p.Type, p, s.constIntPtr(Types[TUINTPTR], n.Xoffset)) + return s.newValue2(ssa.OpLoad, n.Type, p, s.mem()) + + case OINDEX: + if n.Left.Type.Bound >= 0 { // array or string + a := s.expr(n.Left) + i := s.expr(n.Right) + i = s.extendIndex(i) + var elemtype *Type + var len *ssa.Value + if n.Left.Type.IsString() { + len = s.newValue1(ssa.OpStringLen, Types[TINT], a) + elemtype = Types[TUINT8] + } else { + len = s.constInt(Types[TINT], n.Left.Type.Bound) + elemtype = n.Left.Type.Type + } + if !n.Bounded { + s.boundsCheck(i, len) + } + return s.newValue2(ssa.OpArrayIndex, elemtype, a, i) + } else { // slice + p := s.addr(n) + return s.newValue2(ssa.OpLoad, n.Left.Type.Type, p, s.mem()) + } + + case OLEN, OCAP: + switch { + case n.Left.Type.IsSlice(): + op := ssa.OpSliceLen + if n.Op == OCAP { + op = ssa.OpSliceCap + } + return s.newValue1(op, Types[TINT], s.expr(n.Left)) + case n.Left.Type.IsString(): // string; not reachable for OCAP + return s.newValue1(ssa.OpStringLen, Types[TINT], s.expr(n.Left)) + case n.Left.Type.IsMap(), n.Left.Type.IsChan(): + return s.referenceTypeBuiltin(n, s.expr(n.Left)) + default: // array + return s.constInt(Types[TINT], n.Left.Type.Bound) + } + + case OSPTR: + a := s.expr(n.Left) + if n.Left.Type.IsSlice() { + return s.newValue1(ssa.OpSlicePtr, n.Type, a) + } else { + return s.newValue1(ssa.OpStringPtr, n.Type, a) + } + + case OITAB: + a := s.expr(n.Left) + return s.newValue1(ssa.OpITab, n.Type, a) + + case OEFACE: + tab := s.expr(n.Left) + data := s.expr(n.Right) + return s.newValue2(ssa.OpIMake, n.Type, tab, data) + + case OSLICESTR: + // Evaluate the string once. + str := s.expr(n.Left) + ptr := s.newValue1(ssa.OpStringPtr, Ptrto(Types[TUINT8]), str) + len := s.newValue1(ssa.OpStringLen, Types[TINT], str) + zero := s.constInt(Types[TINT], 0) + + // Evaluate the slice indexes. + var low, high *ssa.Value + if n.Right.Left == nil { + low = zero + } else { + low = s.extendIndex(s.expr(n.Right.Left)) + } + if n.Right.Right == nil { + high = len + } else { + high = s.extendIndex(s.expr(n.Right.Right)) + } + + // Panic if slice indices are not in bounds. + s.sliceBoundsCheck(low, high) + s.sliceBoundsCheck(high, len) + + // Generate the following code assuming that indexes are in bounds. + // The conditional is to make sure that we don't generate a string + // that points to the next object in memory. + // rlen = (SubPtr high low) + // p = ptr + // if rlen != 0 { + // p = (AddPtr ptr low) + // } + // result = (StringMake p size) + rlen := s.newValue2(ssa.OpSubPtr, Types[TINT], high, low) + + // Use n as the "variable" for p. + s.vars[n] = ptr + + // Generate code to test the resulting slice length. + var cmp *ssa.Value + if s.config.IntSize == 8 { + cmp = s.newValue2(ssa.OpNeq64, Types[TBOOL], rlen, zero) + } else { + cmp = s.newValue2(ssa.OpNeq32, Types[TBOOL], rlen, zero) + } + + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Likely = ssa.BranchLikely + b.Control = cmp + + // Generate code for non-zero length slice case. + nz := s.f.NewBlock(ssa.BlockPlain) + b.AddEdgeTo(nz) + s.startBlock(nz) + s.vars[n] = s.newValue2(ssa.OpAddPtr, Ptrto(Types[TUINT8]), ptr, low) + s.endBlock() + + // All done. + merge := s.f.NewBlock(ssa.BlockPlain) + b.AddEdgeTo(merge) + nz.AddEdgeTo(merge) + s.startBlock(merge) + return s.newValue2(ssa.OpStringMake, Types[TSTRING], s.variable(n, Ptrto(Types[TUINT8])), rlen) + + case OCALLFUNC, OCALLMETH: + left := n.Left + static := left.Op == ONAME && left.Class == PFUNC + + if n.Op == OCALLMETH { + // Rewrite to an OCALLFUNC: (p.f)(...) becomes (f)(p, ...) + // Take care not to modify the original AST. + if left.Op != ODOTMETH { - Fatal("OCALLMETH: n.Left not an ODOTMETH: %v", left) ++ Fatalf("OCALLMETH: n.Left not an ODOTMETH: %v", left) + } + + newLeft := *left.Right + newLeft.Type = left.Type + if newLeft.Op == ONAME { + newLeft.Class = PFUNC + } + left = &newLeft + static = true + } + + // evaluate closure + var closure *ssa.Value + if !static { + closure = s.expr(left) + } + + // run all argument assignments + s.stmtList(n.List) + + bNext := s.f.NewBlock(ssa.BlockPlain) + var call *ssa.Value + if static { + call = s.newValue1A(ssa.OpStaticCall, ssa.TypeMem, left.Sym, s.mem()) + } else { + entry := s.newValue2(ssa.OpLoad, Types[TUINTPTR], closure, s.mem()) + call = s.newValue3(ssa.OpClosureCall, ssa.TypeMem, entry, closure, s.mem()) + } + dowidth(left.Type) + call.AuxInt = left.Type.Argwid // call operations carry the argsize of the callee along with them + s.vars[&memvar] = call + b := s.endBlock() + b.Kind = ssa.BlockCall + b.Control = call + b.AddEdgeTo(bNext) + b.AddEdgeTo(s.exit) + + // read result from stack at the start of the fallthrough block + s.startBlock(bNext) + var titer Iter + fp := Structfirst(&titer, Getoutarg(left.Type)) + if fp == nil { + // CALLFUNC has no return value. Continue with the next statement. + return nil + } + a := s.entryNewValue1I(ssa.OpOffPtr, Ptrto(fp.Type), fp.Width, s.sp) + return s.newValue2(ssa.OpLoad, fp.Type, a, call) + + case OGETG: + return s.newValue0(ssa.OpGetG, n.Type) + + default: + s.Unimplementedf("unhandled expr %s", opnames[n.Op]) + return nil + } +} + +func (s *state) assign(op uint8, left *Node, right *Node) { + if left.Op == ONAME && isblank(left) { + if right != nil { + s.expr(right) + } + return + } + // TODO: do write barrier + // if op == OASWB + t := left.Type + dowidth(t) + var val *ssa.Value + if right == nil { + // right == nil means use the zero value of the assigned type. + if !canSSA(left) { + // if we can't ssa this memory, treat it as just zeroing out the backing memory + addr := s.addr(left) + if left.Op == ONAME { + s.vars[&memvar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, left, s.mem()) + } + s.vars[&memvar] = s.newValue2I(ssa.OpZero, ssa.TypeMem, t.Size(), addr, s.mem()) + return + } + val = s.zeroVal(t) + } else { + val = s.expr(right) + } + if left.Op == ONAME && canSSA(left) { + // Update variable assignment. + s.vars[left] = val + return + } + // not ssa-able. Treat as a store. + addr := s.addr(left) + if left.Op == ONAME { + s.vars[&memvar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, left, s.mem()) + } + s.vars[&memvar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, t.Size(), addr, val, s.mem()) +} + +// zeroVal returns the zero value for type t. +func (s *state) zeroVal(t *Type) *ssa.Value { + switch { + case t.IsInteger(): + switch t.Size() { + case 1: + return s.constInt8(t, 0) + case 2: + return s.constInt16(t, 0) + case 4: + return s.constInt32(t, 0) + case 8: + return s.constInt64(t, 0) + default: + s.Fatalf("bad sized integer type %s", t) + } + case t.IsFloat(): + switch t.Size() { + case 4: + return s.constFloat32(t, 0) + case 8: + return s.constFloat64(t, 0) + default: + s.Fatalf("bad sized float type %s", t) + } + case t.IsComplex(): + switch t.Size() { + case 8: + z := s.constFloat32(Types[TFLOAT32], 0) + return s.entryNewValue2(ssa.OpComplexMake, t, z, z) + case 16: + z := s.constFloat64(Types[TFLOAT64], 0) + return s.entryNewValue2(ssa.OpComplexMake, t, z, z) + default: + s.Fatalf("bad sized complex type %s", t) + } + + case t.IsString(): + return s.entryNewValue0A(ssa.OpConstString, t, "") + case t.IsPtr(): + return s.entryNewValue0(ssa.OpConstNil, t) + case t.IsBoolean(): + return s.entryNewValue0I(ssa.OpConstBool, Types[TBOOL], 0) // 0 = false + case t.IsInterface(): + return s.entryNewValue0(ssa.OpConstInterface, t) + case t.IsSlice(): + return s.entryNewValue0(ssa.OpConstSlice, t) + } + s.Unimplementedf("zero for type %v not implemented", t) + return nil +} + +// etypesign returns the signed-ness of e, for integer/pointer etypes. +// -1 means signed, +1 means unsigned, 0 means non-integer/non-pointer. +func etypesign(e uint8) int8 { + switch e { + case TINT8, TINT16, TINT32, TINT64, TINT: + return -1 + case TUINT8, TUINT16, TUINT32, TUINT64, TUINT, TUINTPTR, TUNSAFEPTR: + return +1 + } + return 0 +} + +// addr converts the address of the expression n to SSA, adds it to s and returns the SSA result. +// The value that the returned Value represents is guaranteed to be non-nil. +func (s *state) addr(n *Node) *ssa.Value { + switch n.Op { + case ONAME: + switch n.Class { + case PEXTERN: + // global variable + aux := &ssa.ExternSymbol{n.Type, n.Sym} + v := s.entryNewValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sb) + // TODO: Make OpAddr use AuxInt as well as Aux. + if n.Xoffset != 0 { + v = s.entryNewValue1I(ssa.OpOffPtr, v.Type, n.Xoffset, v) + } + return v + case PPARAM, PPARAMOUT: + // parameter/result slot or local variable + v := s.decladdrs[n] + if v == nil { + if flag_race != 0 && n.String() == ".fp" { + s.Unimplementedf("race detector mishandles nodfp") + } + s.Fatalf("addr of undeclared ONAME %v. declared: %v", n, s.decladdrs) + } + return v + case PAUTO: + // We need to regenerate the address of autos + // at every use. This prevents LEA instructions + // from occurring before the corresponding VarDef + // op and confusing the liveness analysis into thinking + // the variable is live at function entry. + // TODO: I'm not sure if this really works or we're just + // getting lucky. We might need a real dependency edge + // between vardef and addr ops. + aux := &ssa.AutoSymbol{Typ: n.Type, Node: n} + return s.newValue1A(ssa.OpAddr, Ptrto(n.Type), aux, s.sp) + case PAUTO | PHEAP, PPARAMREF: + return s.expr(n.Name.Heapaddr) + default: + s.Unimplementedf("variable address class %v not implemented", n.Class) + return nil + } + case OINDREG: + // indirect off a register + // used for storing/loading arguments/returns to/from callees + if int(n.Reg) != Thearch.REGSP { + s.Unimplementedf("OINDREG of non-SP register %s in addr: %v", obj.Rconv(int(n.Reg)), n) + return nil + } + return s.entryNewValue1I(ssa.OpOffPtr, Ptrto(n.Type), n.Xoffset, s.sp) + case OINDEX: + if n.Left.Type.IsSlice() { + a := s.expr(n.Left) + i := s.expr(n.Right) + i = s.extendIndex(i) + len := s.newValue1(ssa.OpSliceLen, Types[TUINTPTR], a) + if !n.Bounded { + s.boundsCheck(i, len) + } + p := s.newValue1(ssa.OpSlicePtr, Ptrto(n.Left.Type.Type), a) + return s.newValue2(ssa.OpPtrIndex, Ptrto(n.Left.Type.Type), p, i) + } else { // array + a := s.addr(n.Left) + i := s.expr(n.Right) + i = s.extendIndex(i) + len := s.constInt(Types[TINT], n.Left.Type.Bound) + if !n.Bounded { + s.boundsCheck(i, len) + } + return s.newValue2(ssa.OpPtrIndex, Ptrto(n.Left.Type.Type), a, i) + } + case OIND: + p := s.expr(n.Left) + s.nilCheck(p) + return p + case ODOT: + p := s.addr(n.Left) + return s.newValue2(ssa.OpAddPtr, p.Type, p, s.constIntPtr(Types[TUINTPTR], n.Xoffset)) + case ODOTPTR: + p := s.expr(n.Left) + s.nilCheck(p) + return s.newValue2(ssa.OpAddPtr, p.Type, p, s.constIntPtr(Types[TUINTPTR], n.Xoffset)) + default: + s.Unimplementedf("unhandled addr %v", Oconv(int(n.Op), 0)) + return nil + } +} + +// canSSA reports whether n is SSA-able. +// n must be an ONAME. +func canSSA(n *Node) bool { + if n.Op != ONAME { + return false + } + if n.Addrtaken { + return false + } + if n.Class&PHEAP != 0 { + return false + } + switch n.Class { + case PEXTERN, PPARAMOUT, PPARAMREF: + return false + } + return canSSAType(n.Type) + // TODO: try to make more variables SSAable? +} + +// canSSA reports whether variables of type t are SSA-able. +func canSSAType(t *Type) bool { + dowidth(t) + if t.Width > int64(4*Widthptr) { + // 4*Widthptr is an arbitrary constant. We want it + // to be at least 3*Widthptr so slices can be registerized. + // Too big and we'll introduce too much register pressure. + return false + } + switch t.Etype { + case TARRAY: + if Isslice(t) { + return true + } + // We can't do arrays because dynamic indexing is + // not supported on SSA variables. + // TODO: maybe allow if length is <=1? All indexes + // are constant? Might be good for the arrays + // introduced by the compiler for variadic functions. + return false + case TSTRUCT: + if countfield(t) > 4 { + // 4 is an arbitrary constant. Same reasoning + // as above, lots of small fields would waste + // register space needed by other values. + return false + } + for t1 := t.Type; t1 != nil; t1 = t1.Down { + if !canSSAType(t1.Type) { + return false + } + } + return false // until it is implemented + //return true + default: + return true + } +} + +// nilCheck generates nil pointer checking code. +// Starts a new block on return, unless nil checks are disabled. +// Used only for automatically inserted nil checks, +// not for user code like 'x != nil'. +func (s *state) nilCheck(ptr *ssa.Value) { + if Disable_checknil != 0 { + return + } + c := s.newValue1(ssa.OpIsNonNil, Types[TBOOL], ptr) + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Control = c + b.Likely = ssa.BranchLikely + bNext := s.f.NewBlock(ssa.BlockPlain) + bPanic := s.f.NewBlock(ssa.BlockPlain) + b.AddEdgeTo(bNext) + b.AddEdgeTo(bPanic) + bPanic.AddEdgeTo(s.exit) + s.startBlock(bPanic) + // TODO: implicit nil checks somehow? + s.vars[&memvar] = s.newValue2(ssa.OpPanicNilCheck, ssa.TypeMem, ptr, s.mem()) + s.endBlock() + s.startBlock(bNext) +} + +// boundsCheck generates bounds checking code. Checks if 0 <= idx < len, branches to exit if not. +// Starts a new block on return. +func (s *state) boundsCheck(idx, len *ssa.Value) { + if Debug['B'] != 0 { + return + } + // TODO: convert index to full width? + // TODO: if index is 64-bit and we're compiling to 32-bit, check that high 32 bits are zero. + + // bounds check + cmp := s.newValue2(ssa.OpIsInBounds, Types[TBOOL], idx, len) + s.check(cmp, ssa.OpPanicIndexCheck) +} + +// sliceBoundsCheck generates slice bounds checking code. Checks if 0 <= idx <= len, branches to exit if not. +// Starts a new block on return. +func (s *state) sliceBoundsCheck(idx, len *ssa.Value) { + if Debug['B'] != 0 { + return + } + // TODO: convert index to full width? + // TODO: if index is 64-bit and we're compiling to 32-bit, check that high 32 bits are zero. + + // bounds check + cmp := s.newValue2(ssa.OpIsSliceInBounds, Types[TBOOL], idx, len) + s.check(cmp, ssa.OpPanicSliceCheck) +} + +// If cmp (a bool) is true, panic using the given op. +func (s *state) check(cmp *ssa.Value, panicOp ssa.Op) { + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Control = cmp + b.Likely = ssa.BranchLikely + bNext := s.f.NewBlock(ssa.BlockPlain) + bPanic := s.f.NewBlock(ssa.BlockPlain) + b.AddEdgeTo(bNext) + b.AddEdgeTo(bPanic) + bPanic.AddEdgeTo(s.exit) + s.startBlock(bPanic) + // The panic check takes/returns memory to ensure that the right + // memory state is observed if the panic happens. + s.vars[&memvar] = s.newValue1(panicOp, ssa.TypeMem, s.mem()) + s.endBlock() + s.startBlock(bNext) +} + +type u2fcvtTab struct { + geq, cvt2F, and, rsh, or, add ssa.Op + one func(*state, ssa.Type, int64) *ssa.Value +} + +var u64_f64 u2fcvtTab = u2fcvtTab{ + geq: ssa.OpGeq64, + cvt2F: ssa.OpCvt64to64F, + and: ssa.OpAnd64, + rsh: ssa.OpRsh64Ux64, + or: ssa.OpOr64, + add: ssa.OpAdd64F, + one: (*state).constInt64, +} + +var u64_f32 u2fcvtTab = u2fcvtTab{ + geq: ssa.OpGeq64, + cvt2F: ssa.OpCvt64to32F, + and: ssa.OpAnd64, + rsh: ssa.OpRsh64Ux64, + or: ssa.OpOr64, + add: ssa.OpAdd32F, + one: (*state).constInt64, +} + +// Excess generality on a machine with 64-bit integer registers. +// Not used on AMD64. +var u32_f32 u2fcvtTab = u2fcvtTab{ + geq: ssa.OpGeq32, + cvt2F: ssa.OpCvt32to32F, + and: ssa.OpAnd32, + rsh: ssa.OpRsh32Ux32, + or: ssa.OpOr32, + add: ssa.OpAdd32F, + one: func(s *state, t ssa.Type, x int64) *ssa.Value { + return s.constInt32(t, int32(x)) + }, +} + +func (s *state) uint64Tofloat64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value { + return s.uintTofloat(&u64_f64, n, x, ft, tt) +} + +func (s *state) uint64Tofloat32(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value { + return s.uintTofloat(&u64_f32, n, x, ft, tt) +} + +func (s *state) uintTofloat(cvttab *u2fcvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value { + // if x >= 0 { + // result = (floatY) x + // } else { + // y = uintX(x) ; y = x & 1 + // z = uintX(x) ; z = z >> 1 + // z = z >> 1 + // z = z | y + // result = floatY(z) + // result = result + result + // } + // + // Code borrowed from old code generator. + // What's going on: large 64-bit "unsigned" looks like + // negative number to hardware's integer-to-float + // conversion. However, because the mantissa is only + // 63 bits, we don't need the LSB, so instead we do an + // unsigned right shift (divide by two), convert, and + // double. However, before we do that, we need to be + // sure that we do not lose a "1" if that made the + // difference in the resulting rounding. Therefore, we + // preserve it, and OR (not ADD) it back in. The case + // that matters is when the eleven discarded bits are + // equal to 10000000001; that rounds up, and the 1 cannot + // be lost else it would round down if the LSB of the + // candidate mantissa is 0. + cmp := s.newValue2(cvttab.geq, Types[TBOOL], x, s.zeroVal(ft)) + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Control = cmp + b.Likely = ssa.BranchLikely + + bThen := s.f.NewBlock(ssa.BlockPlain) + bElse := s.f.NewBlock(ssa.BlockPlain) + bAfter := s.f.NewBlock(ssa.BlockPlain) + + b.AddEdgeTo(bThen) + s.startBlock(bThen) + a0 := s.newValue1(cvttab.cvt2F, tt, x) + s.vars[n] = a0 + s.endBlock() + bThen.AddEdgeTo(bAfter) + + b.AddEdgeTo(bElse) + s.startBlock(bElse) + one := cvttab.one(s, ft, 1) + y := s.newValue2(cvttab.and, ft, x, one) + z := s.newValue2(cvttab.rsh, ft, x, one) + z = s.newValue2(cvttab.or, ft, z, y) + a := s.newValue1(cvttab.cvt2F, tt, z) + a1 := s.newValue2(cvttab.add, tt, a, a) + s.vars[n] = a1 + s.endBlock() + bElse.AddEdgeTo(bAfter) + + s.startBlock(bAfter) + return s.variable(n, n.Type) +} + +// referenceTypeBuiltin generates code for the len/cap builtins for maps and channels. +func (s *state) referenceTypeBuiltin(n *Node, x *ssa.Value) *ssa.Value { + if !n.Left.Type.IsMap() && !n.Left.Type.IsChan() { + s.Fatalf("node must be a map or a channel") + } + // if n == nil { + // return 0 + // } else { + // // len + // return *((*int)n) + // // cap + // return *(((*int)n)+1) + // } + lenType := n.Type + nilValue := s.newValue0(ssa.OpConstNil, Types[TUINTPTR]) + cmp := s.newValue2(ssa.OpEqPtr, Types[TBOOL], x, nilValue) + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Control = cmp + b.Likely = ssa.BranchUnlikely + + bThen := s.f.NewBlock(ssa.BlockPlain) + bElse := s.f.NewBlock(ssa.BlockPlain) + bAfter := s.f.NewBlock(ssa.BlockPlain) + + // length/capacity of a nil map/chan is zero + b.AddEdgeTo(bThen) + s.startBlock(bThen) + s.vars[n] = s.zeroVal(lenType) + s.endBlock() + bThen.AddEdgeTo(bAfter) + + b.AddEdgeTo(bElse) + s.startBlock(bElse) + if n.Op == OLEN { + // length is stored in the first word for map/chan + s.vars[n] = s.newValue2(ssa.OpLoad, lenType, x, s.mem()) + } else if n.Op == OCAP { + // capacity is stored in the second word for chan + sw := s.newValue1I(ssa.OpOffPtr, lenType.PtrTo(), lenType.Width, x) + s.vars[n] = s.newValue2(ssa.OpLoad, lenType, sw, s.mem()) + } else { + s.Fatalf("op must be OLEN or OCAP") + } + s.endBlock() + bElse.AddEdgeTo(bAfter) + + s.startBlock(bAfter) + return s.variable(n, lenType) +} + +type f2uCvtTab struct { + ltf, cvt2U, subf ssa.Op + value func(*state, ssa.Type, float64) *ssa.Value +} + +var f32_u64 f2uCvtTab = f2uCvtTab{ + ltf: ssa.OpLess32F, + cvt2U: ssa.OpCvt32Fto64, + subf: ssa.OpSub32F, + value: (*state).constFloat32, +} + +var f64_u64 f2uCvtTab = f2uCvtTab{ + ltf: ssa.OpLess64F, + cvt2U: ssa.OpCvt64Fto64, + subf: ssa.OpSub64F, + value: (*state).constFloat64, +} + +func (s *state) float32ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value { + return s.floatToUint(&f32_u64, n, x, ft, tt) +} +func (s *state) float64ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value { + return s.floatToUint(&f64_u64, n, x, ft, tt) +} + +func (s *state) floatToUint(cvttab *f2uCvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value { + // if x < 9223372036854775808.0 { + // result = uintY(x) + // } else { + // y = x - 9223372036854775808.0 + // z = uintY(y) + // result = z | -9223372036854775808 + // } + twoToThe63 := cvttab.value(s, ft, 9223372036854775808.0) + cmp := s.newValue2(cvttab.ltf, Types[TBOOL], x, twoToThe63) + b := s.endBlock() + b.Kind = ssa.BlockIf + b.Control = cmp + b.Likely = ssa.BranchLikely + + bThen := s.f.NewBlock(ssa.BlockPlain) + bElse := s.f.NewBlock(ssa.BlockPlain) + bAfter := s.f.NewBlock(ssa.BlockPlain) + + b.AddEdgeTo(bThen) + s.startBlock(bThen) + a0 := s.newValue1(cvttab.cvt2U, tt, x) + s.vars[n] = a0 + s.endBlock() + bThen.AddEdgeTo(bAfter) + + b.AddEdgeTo(bElse) + s.startBlock(bElse) + y := s.newValue2(cvttab.subf, ft, x, twoToThe63) + y = s.newValue1(cvttab.cvt2U, tt, y) + z := s.constInt64(tt, -9223372036854775808) + a1 := s.newValue2(ssa.OpOr64, tt, y, z) + s.vars[n] = a1 + s.endBlock() + bElse.AddEdgeTo(bAfter) + + s.startBlock(bAfter) + return s.variable(n, n.Type) +} + +// checkgoto checks that a goto from from to to does not +// jump into a block or jump over variable declarations. +// It is a copy of checkgoto in the pre-SSA backend, +// modified only for line number handling. +// TODO: document how this works and why it is designed the way it is. +func (s *state) checkgoto(from *Node, to *Node) { + if from.Sym == to.Sym { + return + } + + nf := 0 + for fs := from.Sym; fs != nil; fs = fs.Link { + nf++ + } + nt := 0 + for fs := to.Sym; fs != nil; fs = fs.Link { + nt++ + } + fs := from.Sym + for ; nf > nt; nf-- { + fs = fs.Link + } + if fs != to.Sym { + // decide what to complain about. + // prefer to complain about 'into block' over declarations, + // so scan backward to find most recent block or else dcl. + var block *Sym + + var dcl *Sym + ts := to.Sym + for ; nt > nf; nt-- { + if ts.Pkg == nil { + block = ts + } else { + dcl = ts + } + ts = ts.Link + } + + for ts != fs { + if ts.Pkg == nil { + block = ts + } else { + dcl = ts + } + ts = ts.Link + fs = fs.Link + } + + lno := int(from.Left.Lineno) + if block != nil { + yyerrorl(lno, "goto %v jumps into block starting at %v", from.Left.Sym, Ctxt.Line(int(block.Lastlineno))) + } else { + yyerrorl(lno, "goto %v jumps over declaration of %v at %v", from.Left.Sym, dcl, Ctxt.Line(int(dcl.Lastlineno))) + } + } +} + +// variable returns the value of a variable at the current location. +func (s *state) variable(name *Node, t ssa.Type) *ssa.Value { + v := s.vars[name] + if v == nil { + // TODO: get type? Take Sym as arg? + v = s.newValue0A(ssa.OpFwdRef, t, name) + s.vars[name] = v + } + return v +} + +func (s *state) mem() *ssa.Value { + return s.variable(&memvar, ssa.TypeMem) +} + +func (s *state) linkForwardReferences() { + // Build ssa graph. Each variable on its first use in a basic block + // leaves a FwdRef in that block representing the incoming value + // of that variable. This function links that ref up with possible definitions, + // inserting Phi values as needed. This is essentially the algorithm + // described by Brau, Buchwald, Hack, Leißa, Mallon, and Zwinkau: + // http://pp.info.uni-karlsruhe.de/uploads/publikationen/braun13cc.pdf + for _, b := range s.f.Blocks { + for _, v := range b.Values { + if v.Op != ssa.OpFwdRef { + continue + } + name := v.Aux.(*Node) + v.Op = ssa.OpCopy + v.Aux = nil + v.SetArgs1(s.lookupVarIncoming(b, v.Type, name)) + } + } +} + +// lookupVarIncoming finds the variable's value at the start of block b. +func (s *state) lookupVarIncoming(b *ssa.Block, t ssa.Type, name *Node) *ssa.Value { + // TODO(khr): have lookupVarIncoming overwrite the fwdRef or copy it + // will be used in, instead of having the result used in a copy value. + if b == s.f.Entry { + if name == &memvar { + return s.startmem + } + // variable is live at the entry block. Load it. + addr := s.decladdrs[name] + if addr == nil { + // TODO: closure args reach here. + s.Unimplementedf("unhandled closure arg") + } + if _, ok := addr.Aux.(*ssa.ArgSymbol); !ok { + s.Fatalf("variable live at start of function %s is not an argument %s", b.Func.Name, name) + } + return s.entryNewValue2(ssa.OpLoad, t, addr, s.startmem) + } + var vals []*ssa.Value + for _, p := range b.Preds { + vals = append(vals, s.lookupVarOutgoing(p, t, name)) + } + if len(vals) == 0 { + // This block is dead; we have no predecessors and we're not the entry block. + // It doesn't matter what we use here as long as it is well-formed, + // so use the default/zero value. + if name == &memvar { + return s.startmem + } + return s.zeroVal(name.Type) + } + v0 := vals[0] + for i := 1; i < len(vals); i++ { + if vals[i] != v0 { + // need a phi value + v := b.NewValue0(s.peekLine(), ssa.OpPhi, t) + v.AddArgs(vals...) + return v + } + } + return v0 +} + +// lookupVarOutgoing finds the variable's value at the end of block b. +func (s *state) lookupVarOutgoing(b *ssa.Block, t ssa.Type, name *Node) *ssa.Value { + m := s.defvars[b.ID] + if v, ok := m[name]; ok { + return v + } + // The variable is not defined by b and we haven't + // looked it up yet. Generate v, a copy value which + // will be the outgoing value of the variable. Then + // look up w, the incoming value of the variable. + // Make v = copy(w). We need the extra copy to + // prevent infinite recursion when looking up the + // incoming value of the variable. + v := b.NewValue0(s.peekLine(), ssa.OpCopy, t) + m[name] = v + v.AddArg(s.lookupVarIncoming(b, t, name)) + return v +} + +// TODO: the above mutually recursive functions can lead to very deep stacks. Fix that. + +// an unresolved branch +type branch struct { + p *obj.Prog // branch instruction + b *ssa.Block // target +} + +type genState struct { + // branches remembers all the branch instructions we've seen + // and where they would like to go. + branches []branch + + // bstart remembers where each block starts (indexed by block ID) + bstart []*obj.Prog + + // deferBranches remembers all the defer branches we've seen. + deferBranches []*obj.Prog + + // deferTarget remembers the (last) deferreturn call site. + deferTarget *obj.Prog +} + +// genssa appends entries to ptxt for each instruction in f. +// gcargs and gclocals are filled in with pointer maps for the frame. +func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) { + var s genState + + e := f.Config.Frontend().(*ssaExport) + // We're about to emit a bunch of Progs. + // Since the only way to get here is to explicitly request it, + // just fail on unimplemented instead of trying to unwind our mess. + e.mustImplement = true + + // Remember where each block starts. + s.bstart = make([]*obj.Prog, f.NumBlocks()) + + var valueProgs map[*obj.Prog]*ssa.Value + var blockProgs map[*obj.Prog]*ssa.Block + const logProgs = true + if logProgs { + valueProgs = make(map[*obj.Prog]*ssa.Value, f.NumValues()) + blockProgs = make(map[*obj.Prog]*ssa.Block, f.NumBlocks()) + f.Logf("genssa %s\n", f.Name) + blockProgs[Pc] = f.Blocks[0] + } + + // Emit basic blocks + for i, b := range f.Blocks { + s.bstart[b.ID] = Pc + // Emit values in block + for _, v := range b.Values { + x := Pc + s.genValue(v) + if logProgs { + for ; x != Pc; x = x.Link { + valueProgs[x] = v + } + } + } + // Emit control flow instructions for block + var next *ssa.Block + if i < len(f.Blocks)-1 { + next = f.Blocks[i+1] + } + x := Pc + s.genBlock(b, next) + if logProgs { + for ; x != Pc; x = x.Link { + blockProgs[x] = b + } + } + } + + // Resolve branches + for _, br := range s.branches { + br.p.To.Val = s.bstart[br.b.ID] + } + if s.deferBranches != nil && s.deferTarget == nil { + // This can happen when the function has a defer but + // no return (because it has an infinite loop). + s.deferReturn() + Prog(obj.ARET) + } + for _, p := range s.deferBranches { + p.To.Val = s.deferTarget + } + + Pc.As = obj.ARET // overwrite AEND + + if logProgs { + for p := ptxt; p != nil; p = p.Link { + var s string + if v, ok := valueProgs[p]; ok { + s = v.String() + } else if b, ok := blockProgs[p]; ok { + s = b.String() + } else { + s = " " // most value and branch strings are 2-3 characters long + } + f.Logf("%s\t%s\n", s, p) + } + if f.Config.HTML != nil { + saved := ptxt.Ctxt.LineHist.PrintFilenameOnly + ptxt.Ctxt.LineHist.PrintFilenameOnly = true + var buf bytes.Buffer + buf.WriteString("") + buf.WriteString("
") + for p := ptxt; p != nil; p = p.Link { + buf.WriteString("
") + if v, ok := valueProgs[p]; ok { + buf.WriteString(v.HTML()) + } else if b, ok := blockProgs[p]; ok { + buf.WriteString(b.HTML()) + } + buf.WriteString("
") + buf.WriteString("
") + buf.WriteString(html.EscapeString(p.String())) + buf.WriteString("
") + buf.WriteString("") + } + buf.WriteString("
") + buf.WriteString("") + f.Config.HTML.WriteColumn("genssa", buf.String()) + ptxt.Ctxt.LineHist.PrintFilenameOnly = saved + } + } + + // Emit static data + if f.StaticData != nil { + for _, n := range f.StaticData.([]*Node) { + if !gen_as_init(n, false) { - Fatal("non-static data marked as static: %v\n\n", n, f) ++ Fatalf("non-static data marked as static: %v\n\n", n, f) + } + } + } + + // Allocate stack frame + allocauto(ptxt) + + // Generate gc bitmaps. + liveness(Curfn, ptxt, gcargs, gclocals) + gcsymdup(gcargs) + gcsymdup(gclocals) + + // Add frame prologue. Zero ambiguously live variables. + Thearch.Defframe(ptxt) + if Debug['f'] != 0 { + frame(0) + } + + // Remove leftover instrumentation from the instruction stream. + removevardef(ptxt) + + f.Config.HTML.Close() +} + +// opregreg emits instructions for +// dest := dest(To) op src(From) +// and also returns the created obj.Prog so it +// may be further adjusted (offset, scale, etc). +func opregreg(op int, dest, src int16) *obj.Prog { + p := Prog(op) + p.From.Type = obj.TYPE_REG + p.To.Type = obj.TYPE_REG + p.To.Reg = dest + p.From.Reg = src + return p +} + +func (s *genState) genValue(v *ssa.Value) { + lineno = v.Line + switch v.Op { + case ssa.OpAMD64ADDQ: + // TODO: use addq instead of leaq if target is in the right register. + p := Prog(x86.ALEAQ) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + p.From.Scale = 1 + p.From.Index = regnum(v.Args[1]) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64ADDL: + p := Prog(x86.ALEAL) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + p.From.Scale = 1 + p.From.Index = regnum(v.Args[1]) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64ADDW: + p := Prog(x86.ALEAW) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + p.From.Scale = 1 + p.From.Index = regnum(v.Args[1]) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + // 2-address opcode arithmetic, symmetric + case ssa.OpAMD64ADDB, ssa.OpAMD64ADDSS, ssa.OpAMD64ADDSD, + ssa.OpAMD64ANDQ, ssa.OpAMD64ANDL, ssa.OpAMD64ANDW, ssa.OpAMD64ANDB, + ssa.OpAMD64ORQ, ssa.OpAMD64ORL, ssa.OpAMD64ORW, ssa.OpAMD64ORB, + ssa.OpAMD64XORQ, ssa.OpAMD64XORL, ssa.OpAMD64XORW, ssa.OpAMD64XORB, + ssa.OpAMD64MULQ, ssa.OpAMD64MULL, ssa.OpAMD64MULW, ssa.OpAMD64MULB, + ssa.OpAMD64MULSS, ssa.OpAMD64MULSD, ssa.OpAMD64PXOR: + r := regnum(v) + x := regnum(v.Args[0]) + y := regnum(v.Args[1]) + if x != r && y != r { + opregreg(regMoveByTypeAMD64(v.Type), r, x) + x = r + } + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.To.Type = obj.TYPE_REG + p.To.Reg = r + if x == r { + p.From.Reg = y + } else { + p.From.Reg = x + } + // 2-address opcode arithmetic, not symmetric + case ssa.OpAMD64SUBQ, ssa.OpAMD64SUBL, ssa.OpAMD64SUBW, ssa.OpAMD64SUBB: + r := regnum(v) + x := regnum(v.Args[0]) + y := regnum(v.Args[1]) + var neg bool + if y == r { + // compute -(y-x) instead + x, y = y, x + neg = true + } + if x != r { + opregreg(regMoveByTypeAMD64(v.Type), r, x) + } + opregreg(v.Op.Asm(), r, y) + + if neg { + p := Prog(x86.ANEGQ) // TODO: use correct size? This is mostly a hack until regalloc does 2-address correctly + p.To.Type = obj.TYPE_REG + p.To.Reg = r + } + case ssa.OpAMD64SUBSS, ssa.OpAMD64SUBSD, ssa.OpAMD64DIVSS, ssa.OpAMD64DIVSD: + r := regnum(v) + x := regnum(v.Args[0]) + y := regnum(v.Args[1]) + if y == r && x != r { + // r/y := x op r/y, need to preserve x and rewrite to + // r/y := r/y op x15 + x15 := int16(x86.REG_X15) + // register move y to x15 + // register move x to y + // rename y with x15 + opregreg(regMoveByTypeAMD64(v.Type), x15, y) + opregreg(regMoveByTypeAMD64(v.Type), r, x) + y = x15 + } else if x != r { + opregreg(regMoveByTypeAMD64(v.Type), r, x) + } + opregreg(v.Op.Asm(), r, y) + + case ssa.OpAMD64DIVQ, ssa.OpAMD64DIVL, ssa.OpAMD64DIVW, + ssa.OpAMD64DIVQU, ssa.OpAMD64DIVLU, ssa.OpAMD64DIVWU, + ssa.OpAMD64MODQ, ssa.OpAMD64MODL, ssa.OpAMD64MODW, + ssa.OpAMD64MODQU, ssa.OpAMD64MODLU, ssa.OpAMD64MODWU: + + // Arg[0] is already in AX as it's the only register we allow + // and AX is the only output + x := regnum(v.Args[1]) + + // CPU faults upon signed overflow, which occurs when most + // negative int is divided by -1. + var j *obj.Prog + if v.Op == ssa.OpAMD64DIVQ || v.Op == ssa.OpAMD64DIVL || + v.Op == ssa.OpAMD64DIVW || v.Op == ssa.OpAMD64MODQ || + v.Op == ssa.OpAMD64MODL || v.Op == ssa.OpAMD64MODW { + + var c *obj.Prog + switch v.Op { + case ssa.OpAMD64DIVQ, ssa.OpAMD64MODQ: + c = Prog(x86.ACMPQ) + j = Prog(x86.AJEQ) + // go ahead and sign extend to save doing it later + Prog(x86.ACQO) + + case ssa.OpAMD64DIVL, ssa.OpAMD64MODL: + c = Prog(x86.ACMPL) + j = Prog(x86.AJEQ) + Prog(x86.ACDQ) + + case ssa.OpAMD64DIVW, ssa.OpAMD64MODW: + c = Prog(x86.ACMPW) + j = Prog(x86.AJEQ) + Prog(x86.ACWD) + } + c.From.Type = obj.TYPE_REG + c.From.Reg = x + c.To.Type = obj.TYPE_CONST + c.To.Offset = -1 + + j.To.Type = obj.TYPE_BRANCH + + } + + // for unsigned ints, we sign extend by setting DX = 0 + // signed ints were sign extended above + if v.Op == ssa.OpAMD64DIVQU || v.Op == ssa.OpAMD64MODQU || + v.Op == ssa.OpAMD64DIVLU || v.Op == ssa.OpAMD64MODLU || + v.Op == ssa.OpAMD64DIVWU || v.Op == ssa.OpAMD64MODWU { + c := Prog(x86.AXORQ) + c.From.Type = obj.TYPE_REG + c.From.Reg = x86.REG_DX + c.To.Type = obj.TYPE_REG + c.To.Reg = x86.REG_DX + } + + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = x + + // signed division, rest of the check for -1 case + if j != nil { + j2 := Prog(obj.AJMP) + j2.To.Type = obj.TYPE_BRANCH + + var n *obj.Prog + if v.Op == ssa.OpAMD64DIVQ || v.Op == ssa.OpAMD64DIVL || + v.Op == ssa.OpAMD64DIVW { + // n * -1 = -n + n = Prog(x86.ANEGQ) + n.To.Type = obj.TYPE_REG + n.To.Reg = x86.REG_AX + } else { + // n % -1 == 0 + n = Prog(x86.AXORQ) + n.From.Type = obj.TYPE_REG + n.From.Reg = x86.REG_DX + n.To.Type = obj.TYPE_REG + n.To.Reg = x86.REG_DX + } + + j.To.Val = n + j2.To.Val = Pc + } + + case ssa.OpAMD64HMULL, ssa.OpAMD64HMULW, ssa.OpAMD64HMULB, + ssa.OpAMD64HMULLU, ssa.OpAMD64HMULWU, ssa.OpAMD64HMULBU: + // the frontend rewrites constant division by 8/16/32 bit integers into + // HMUL by a constant + + // Arg[0] is already in AX as it's the only register we allow + // and DX is the only output we care about (the high bits) + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = regnum(v.Args[1]) + + // IMULB puts the high portion in AH instead of DL, + // so move it to DL for consistency + if v.Type.Size() == 1 { + m := Prog(x86.AMOVB) + m.From.Type = obj.TYPE_REG + m.From.Reg = x86.REG_AH + m.To.Type = obj.TYPE_REG + m.To.Reg = x86.REG_DX + } + + case ssa.OpAMD64SHLQ, ssa.OpAMD64SHLL, ssa.OpAMD64SHLW, ssa.OpAMD64SHLB, + ssa.OpAMD64SHRQ, ssa.OpAMD64SHRL, ssa.OpAMD64SHRW, ssa.OpAMD64SHRB, + ssa.OpAMD64SARQ, ssa.OpAMD64SARL, ssa.OpAMD64SARW, ssa.OpAMD64SARB: + x := regnum(v.Args[0]) + r := regnum(v) + if x != r { + if r == x86.REG_CX { + v.Fatalf("can't implement %s, target and shift both in CX", v.LongString()) + } + p := Prog(regMoveAMD64(v.Type.Size())) + p.From.Type = obj.TYPE_REG + p.From.Reg = x + p.To.Type = obj.TYPE_REG + p.To.Reg = r + } + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = regnum(v.Args[1]) // should be CX + p.To.Type = obj.TYPE_REG + p.To.Reg = r + case ssa.OpAMD64ADDQconst, ssa.OpAMD64ADDLconst, ssa.OpAMD64ADDWconst: + // TODO: use addq instead of leaq if target is in the right register. + var asm int + switch v.Op { + case ssa.OpAMD64ADDQconst: + asm = x86.ALEAQ + case ssa.OpAMD64ADDLconst: + asm = x86.ALEAL + case ssa.OpAMD64ADDWconst: + asm = x86.ALEAW + } + p := Prog(asm) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + p.From.Offset = v.AuxInt + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64MULQconst, ssa.OpAMD64MULLconst, ssa.OpAMD64MULWconst, ssa.OpAMD64MULBconst: + r := regnum(v) + x := regnum(v.Args[0]) + if r != x { + p := Prog(regMoveAMD64(v.Type.Size())) + p.From.Type = obj.TYPE_REG + p.From.Reg = x + p.To.Type = obj.TYPE_REG + p.To.Reg = r + } + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_CONST + p.From.Offset = v.AuxInt + p.To.Type = obj.TYPE_REG + p.To.Reg = r + // TODO: Teach doasm to compile the three-address multiply imul $c, r1, r2 + // instead of using the MOVQ above. + //p.From3 = new(obj.Addr) + //p.From3.Type = obj.TYPE_REG + //p.From3.Reg = regnum(v.Args[0]) + case ssa.OpAMD64ADDBconst, + ssa.OpAMD64ANDQconst, ssa.OpAMD64ANDLconst, ssa.OpAMD64ANDWconst, ssa.OpAMD64ANDBconst, + ssa.OpAMD64ORQconst, ssa.OpAMD64ORLconst, ssa.OpAMD64ORWconst, ssa.OpAMD64ORBconst, + ssa.OpAMD64XORQconst, ssa.OpAMD64XORLconst, ssa.OpAMD64XORWconst, ssa.OpAMD64XORBconst, + ssa.OpAMD64SUBQconst, ssa.OpAMD64SUBLconst, ssa.OpAMD64SUBWconst, ssa.OpAMD64SUBBconst, + ssa.OpAMD64SHLQconst, ssa.OpAMD64SHLLconst, ssa.OpAMD64SHLWconst, ssa.OpAMD64SHLBconst, + ssa.OpAMD64SHRQconst, ssa.OpAMD64SHRLconst, ssa.OpAMD64SHRWconst, ssa.OpAMD64SHRBconst, + ssa.OpAMD64SARQconst, ssa.OpAMD64SARLconst, ssa.OpAMD64SARWconst, ssa.OpAMD64SARBconst, + ssa.OpAMD64ROLQconst, ssa.OpAMD64ROLLconst, ssa.OpAMD64ROLWconst, ssa.OpAMD64ROLBconst: + // This code compensates for the fact that the register allocator + // doesn't understand 2-address instructions yet. TODO: fix that. + x := regnum(v.Args[0]) + r := regnum(v) + if x != r { + p := Prog(regMoveAMD64(v.Type.Size())) + p.From.Type = obj.TYPE_REG + p.From.Reg = x + p.To.Type = obj.TYPE_REG + p.To.Reg = r + } + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_CONST + p.From.Offset = v.AuxInt + p.To.Type = obj.TYPE_REG + p.To.Reg = r + case ssa.OpAMD64SBBQcarrymask, ssa.OpAMD64SBBLcarrymask: + r := regnum(v) + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = r + p.To.Type = obj.TYPE_REG + p.To.Reg = r + case ssa.OpAMD64LEAQ1, ssa.OpAMD64LEAQ2, ssa.OpAMD64LEAQ4, ssa.OpAMD64LEAQ8: + p := Prog(x86.ALEAQ) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + switch v.Op { + case ssa.OpAMD64LEAQ1: + p.From.Scale = 1 + case ssa.OpAMD64LEAQ2: + p.From.Scale = 2 + case ssa.OpAMD64LEAQ4: + p.From.Scale = 4 + case ssa.OpAMD64LEAQ8: + p.From.Scale = 8 + } + p.From.Index = regnum(v.Args[1]) + addAux(&p.From, v) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64LEAQ: + p := Prog(x86.ALEAQ) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + addAux(&p.From, v) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64CMPQ, ssa.OpAMD64CMPL, ssa.OpAMD64CMPW, ssa.OpAMD64CMPB, + ssa.OpAMD64TESTQ, ssa.OpAMD64TESTL, ssa.OpAMD64TESTW, ssa.OpAMD64TESTB: + opregreg(v.Op.Asm(), regnum(v.Args[1]), regnum(v.Args[0])) + case ssa.OpAMD64UCOMISS, ssa.OpAMD64UCOMISD: + // Go assembler has swapped operands for UCOMISx relative to CMP, + // must account for that right here. + opregreg(v.Op.Asm(), regnum(v.Args[0]), regnum(v.Args[1])) + case ssa.OpAMD64CMPQconst, ssa.OpAMD64CMPLconst, ssa.OpAMD64CMPWconst, ssa.OpAMD64CMPBconst, + ssa.OpAMD64TESTQconst, ssa.OpAMD64TESTLconst, ssa.OpAMD64TESTWconst, ssa.OpAMD64TESTBconst: + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = regnum(v.Args[0]) + p.To.Type = obj.TYPE_CONST + p.To.Offset = v.AuxInt + case ssa.OpAMD64MOVBconst, ssa.OpAMD64MOVWconst, ssa.OpAMD64MOVLconst, ssa.OpAMD64MOVQconst: + x := regnum(v) + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_CONST + var i int64 + switch v.Op { + case ssa.OpAMD64MOVBconst: + i = int64(int8(v.AuxInt)) + case ssa.OpAMD64MOVWconst: + i = int64(int16(v.AuxInt)) + case ssa.OpAMD64MOVLconst: + i = int64(int32(v.AuxInt)) + case ssa.OpAMD64MOVQconst: + i = v.AuxInt + } + p.From.Offset = i + p.To.Type = obj.TYPE_REG + p.To.Reg = x + case ssa.OpAMD64MOVSSconst, ssa.OpAMD64MOVSDconst: + x := regnum(v) + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_FCONST + p.From.Val = math.Float64frombits(uint64(v.AuxInt)) + p.To.Type = obj.TYPE_REG + p.To.Reg = x + case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload, ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVBQZXload: + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + addAux(&p.From, v) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64MOVQloadidx8, ssa.OpAMD64MOVSDloadidx8: + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + addAux(&p.From, v) + p.From.Scale = 8 + p.From.Index = regnum(v.Args[1]) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64MOVSSloadidx4: + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_MEM + p.From.Reg = regnum(v.Args[0]) + addAux(&p.From, v) + p.From.Scale = 4 + p.From.Index = regnum(v.Args[1]) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + case ssa.OpAMD64MOVQstore, ssa.OpAMD64MOVSSstore, ssa.OpAMD64MOVSDstore, ssa.OpAMD64MOVLstore, ssa.OpAMD64MOVWstore, ssa.OpAMD64MOVBstore: + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = regnum(v.Args[1]) + p.To.Type = obj.TYPE_MEM + p.To.Reg = regnum(v.Args[0]) + addAux(&p.To, v) + case ssa.OpAMD64MOVQstoreidx8, ssa.OpAMD64MOVSDstoreidx8: + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = regnum(v.Args[2]) + p.To.Type = obj.TYPE_MEM + p.To.Reg = regnum(v.Args[0]) + p.To.Scale = 8 + p.To.Index = regnum(v.Args[1]) + addAux(&p.To, v) + case ssa.OpAMD64MOVSSstoreidx4: + p := Prog(v.Op.Asm()) + p.From.Type = obj.TYPE_REG + p.From.Reg = regnum(v.Args[2]) + p.To.Type = obj.TYPE_MEM + p.To.Reg = regnum(v.Args[0]) + p.To.Scale = 4 + p.To.Index = regnum(v.Args[1]) + addAux(&p.To, v) + case ssa.OpAMD64MOVLQSX, ssa.OpAMD64MOVWQSX, ssa.OpAMD64MOVBQSX, ssa.OpAMD64MOVLQZX, ssa.OpAMD64MOVWQZX, ssa.OpAMD64MOVBQZX, + ssa.OpAMD64CVTSL2SS, ssa.OpAMD64CVTSL2SD, ssa.OpAMD64CVTSQ2SS, ssa.OpAMD64CVTSQ2SD, + ssa.OpAMD64CVTTSS2SL, ssa.OpAMD64CVTTSD2SL, ssa.OpAMD64CVTTSS2SQ, ssa.OpAMD64CVTTSD2SQ, + ssa.OpAMD64CVTSS2SD, ssa.OpAMD64CVTSD2SS: + opregreg(v.Op.Asm(), regnum(v), regnum(v.Args[0])) + case ssa.OpAMD64MOVXzero: + nb := v.AuxInt + offset := int64(0) + reg := regnum(v.Args[0]) + for nb >= 8 { + nb, offset = movZero(x86.AMOVQ, 8, nb, offset, reg) + } + for nb >= 4 { + nb, offset = movZero(x86.AMOVL, 4, nb, offset, reg) + } + for nb >= 2 { + nb, offset = movZero(x86.AMOVW, 2, nb, offset, reg) + } + for nb >= 1 { + nb, offset = movZero(x86.AMOVB, 1, nb, offset, reg) + } + case ssa.OpCopy: // TODO: lower to MOVQ earlier? + if v.Type.IsMemory() { + return + } + x := regnum(v.Args[0]) + y := regnum(v) + if x != y { + opregreg(regMoveByTypeAMD64(v.Type), y, x) + } + case ssa.OpLoadReg: + if v.Type.IsFlags() { + v.Unimplementedf("load flags not implemented: %v", v.LongString()) + return + } + p := Prog(movSizeByType(v.Type)) + n := autoVar(v.Args[0]) + p.From.Type = obj.TYPE_MEM + p.From.Name = obj.NAME_AUTO + p.From.Node = n + p.From.Sym = Linksym(n.Sym) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + + case ssa.OpStoreReg: + if v.Type.IsFlags() { + v.Unimplementedf("store flags not implemented: %v", v.LongString()) + return + } + p := Prog(movSizeByType(v.Type)) + p.From.Type = obj.TYPE_REG + p.From.Reg = regnum(v.Args[0]) + n := autoVar(v) + p.To.Type = obj.TYPE_MEM + p.To.Name = obj.NAME_AUTO + p.To.Node = n + p.To.Sym = Linksym(n.Sym) + case ssa.OpPhi: + // just check to make sure regalloc and stackalloc did it right + if v.Type.IsMemory() { + return + } + f := v.Block.Func + loc := f.RegAlloc[v.ID] + for _, a := range v.Args { + if aloc := f.RegAlloc[a.ID]; aloc != loc { // TODO: .Equal() instead? + v.Fatalf("phi arg at different location than phi: %v @ %v, but arg %v @ %v\n%s\n", v, loc, a, aloc, v.Block.Func) + } + } + case ssa.OpConst8, ssa.OpConst16, ssa.OpConst32, ssa.OpConst64, ssa.OpConstString, ssa.OpConstNil, ssa.OpConstBool, + ssa.OpConst32F, ssa.OpConst64F: + if v.Block.Func.RegAlloc[v.ID] != nil { + v.Fatalf("const value %v shouldn't have a location", v) + } + + case ssa.OpArg: + // memory arg needs no code + // TODO: check that only mem arg goes here. + case ssa.OpAMD64LoweredPanicNilCheck: + if Debug_checknil != 0 && v.Line > 1 { // v.Line==1 in generated wrappers + Warnl(int(v.Line), "generated nil check") + } + // Write to memory address 0. It doesn't matter what we write; use AX. + // Input 0 is the pointer we just checked, use it as the destination. + r := regnum(v.Args[0]) + q := Prog(x86.AMOVL) + q.From.Type = obj.TYPE_REG + q.From.Reg = x86.REG_AX + q.To.Type = obj.TYPE_MEM + q.To.Reg = r + Prog(obj.AUNDEF) // tell plive.go that we never reach here + case ssa.OpAMD64LoweredPanicIndexCheck: + p := Prog(obj.ACALL) + p.To.Type = obj.TYPE_MEM + p.To.Name = obj.NAME_EXTERN + p.To.Sym = Linksym(Panicindex.Sym) + Prog(obj.AUNDEF) + case ssa.OpAMD64LoweredPanicSliceCheck: + p := Prog(obj.ACALL) + p.To.Type = obj.TYPE_MEM + p.To.Name = obj.NAME_EXTERN + p.To.Sym = Linksym(panicslice.Sym) + Prog(obj.AUNDEF) + case ssa.OpAMD64LoweredGetG: + r := regnum(v) + // See the comments in cmd/internal/obj/x86/obj6.go + // near CanUse1InsnTLS for a detailed explanation of these instructions. + if x86.CanUse1InsnTLS(Ctxt) { + // MOVQ (TLS), r + p := Prog(x86.AMOVQ) + p.From.Type = obj.TYPE_MEM + p.From.Reg = x86.REG_TLS + p.To.Type = obj.TYPE_REG + p.To.Reg = r + } else { + // MOVQ TLS, r + // MOVQ (r)(TLS*1), r + p := Prog(x86.AMOVQ) + p.From.Type = obj.TYPE_REG + p.From.Reg = x86.REG_TLS + p.To.Type = obj.TYPE_REG + p.To.Reg = r + q := Prog(x86.AMOVQ) + q.From.Type = obj.TYPE_MEM + q.From.Reg = r + q.From.Index = x86.REG_TLS + q.From.Scale = 1 + q.To.Type = obj.TYPE_REG + q.To.Reg = r + } + case ssa.OpAMD64CALLstatic: + p := Prog(obj.ACALL) + p.To.Type = obj.TYPE_MEM + p.To.Name = obj.NAME_EXTERN + p.To.Sym = Linksym(v.Aux.(*Sym)) + if Maxarg < v.AuxInt { + Maxarg = v.AuxInt + } + case ssa.OpAMD64CALLclosure: + p := Prog(obj.ACALL) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v.Args[0]) + if Maxarg < v.AuxInt { + Maxarg = v.AuxInt + } + case ssa.OpAMD64CALLdefer: + p := Prog(obj.ACALL) + p.To.Type = obj.TYPE_MEM + p.To.Name = obj.NAME_EXTERN + p.To.Sym = Linksym(Deferproc.Sym) + if Maxarg < v.AuxInt { + Maxarg = v.AuxInt + } + // defer returns in rax: + // 0 if we should continue executing + // 1 if we should jump to deferreturn call + p = Prog(x86.ATESTL) + p.From.Type = obj.TYPE_REG + p.From.Reg = x86.REG_AX + p.To.Type = obj.TYPE_REG + p.To.Reg = x86.REG_AX + p = Prog(x86.AJNE) + p.To.Type = obj.TYPE_BRANCH + s.deferBranches = append(s.deferBranches, p) + case ssa.OpAMD64CALLgo: + p := Prog(obj.ACALL) + p.To.Type = obj.TYPE_MEM + p.To.Name = obj.NAME_EXTERN + p.To.Sym = Linksym(Newproc.Sym) + if Maxarg < v.AuxInt { + Maxarg = v.AuxInt + } + case ssa.OpAMD64NEGQ, ssa.OpAMD64NEGL, ssa.OpAMD64NEGW, ssa.OpAMD64NEGB, + ssa.OpAMD64NOTQ, ssa.OpAMD64NOTL, ssa.OpAMD64NOTW, ssa.OpAMD64NOTB: + x := regnum(v.Args[0]) + r := regnum(v) + if x != r { + p := Prog(regMoveAMD64(v.Type.Size())) + p.From.Type = obj.TYPE_REG + p.From.Reg = x + p.To.Type = obj.TYPE_REG + p.To.Reg = r + } + p := Prog(v.Op.Asm()) + p.To.Type = obj.TYPE_REG + p.To.Reg = r + case ssa.OpSP, ssa.OpSB: + // nothing to do + case ssa.OpAMD64SETEQ, ssa.OpAMD64SETNE, + ssa.OpAMD64SETL, ssa.OpAMD64SETLE, + ssa.OpAMD64SETG, ssa.OpAMD64SETGE, + ssa.OpAMD64SETGF, ssa.OpAMD64SETGEF, + ssa.OpAMD64SETB, ssa.OpAMD64SETBE, + ssa.OpAMD64SETORD, ssa.OpAMD64SETNAN, + ssa.OpAMD64SETA, ssa.OpAMD64SETAE: + p := Prog(v.Op.Asm()) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + + case ssa.OpAMD64SETNEF: + p := Prog(v.Op.Asm()) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + q := Prog(x86.ASETPS) + q.To.Type = obj.TYPE_REG + q.To.Reg = x86.REG_AX + // TODO AORQ copied from old code generator, why not AORB? + opregreg(x86.AORQ, regnum(v), x86.REG_AX) + + case ssa.OpAMD64SETEQF: + p := Prog(v.Op.Asm()) + p.To.Type = obj.TYPE_REG + p.To.Reg = regnum(v) + q := Prog(x86.ASETPC) + q.To.Type = obj.TYPE_REG + q.To.Reg = x86.REG_AX + // TODO AANDQ copied from old code generator, why not AANDB? + opregreg(x86.AANDQ, regnum(v), x86.REG_AX) + + case ssa.OpAMD64InvertFlags: + v.Fatalf("InvertFlags should never make it to codegen %v", v) + case ssa.OpAMD64REPSTOSQ: + p := Prog(x86.AXORL) // TODO: lift out zeroing into its own instruction? + p.From.Type = obj.TYPE_REG + p.From.Reg = x86.REG_AX + p.To.Type = obj.TYPE_REG + p.To.Reg = x86.REG_AX + Prog(x86.AREP) + Prog(x86.ASTOSQ) + case ssa.OpAMD64REPMOVSB: + Prog(x86.AREP) + Prog(x86.AMOVSB) + case ssa.OpVarDef: + Gvardef(v.Aux.(*Node)) + case ssa.OpVarKill: + gvarkill(v.Aux.(*Node)) + default: + v.Unimplementedf("genValue not implemented: %s", v.LongString()) + } +} + +// movSizeByType returns the MOV instruction of the given type. +func movSizeByType(t ssa.Type) (asm int) { + // For x86, there's no difference between reg move opcodes + // and memory move opcodes. + asm = regMoveByTypeAMD64(t) + return +} + +// movZero generates a register indirect move with a 0 immediate and keeps track of bytes left and next offset +func movZero(as int, width int64, nbytes int64, offset int64, regnum int16) (nleft int64, noff int64) { + p := Prog(as) + // TODO: use zero register on archs that support it. + p.From.Type = obj.TYPE_CONST + p.From.Offset = 0 + p.To.Type = obj.TYPE_MEM + p.To.Reg = regnum + p.To.Offset = offset + offset += width + nleft = nbytes - width + return nleft, offset +} + +var blockJump = [...]struct { + asm, invasm int +}{ + ssa.BlockAMD64EQ: {x86.AJEQ, x86.AJNE}, + ssa.BlockAMD64NE: {x86.AJNE, x86.AJEQ}, + ssa.BlockAMD64LT: {x86.AJLT, x86.AJGE}, + ssa.BlockAMD64GE: {x86.AJGE, x86.AJLT}, + ssa.BlockAMD64LE: {x86.AJLE, x86.AJGT}, + ssa.BlockAMD64GT: {x86.AJGT, x86.AJLE}, + ssa.BlockAMD64ULT: {x86.AJCS, x86.AJCC}, + ssa.BlockAMD64UGE: {x86.AJCC, x86.AJCS}, + ssa.BlockAMD64UGT: {x86.AJHI, x86.AJLS}, + ssa.BlockAMD64ULE: {x86.AJLS, x86.AJHI}, + ssa.BlockAMD64ORD: {x86.AJPC, x86.AJPS}, + ssa.BlockAMD64NAN: {x86.AJPS, x86.AJPC}, +} + +type floatingEQNEJump struct { + jump, index int +} + +var eqfJumps = [2][2]floatingEQNEJump{ + {{x86.AJNE, 1}, {x86.AJPS, 1}}, // next == b.Succs[0] + {{x86.AJNE, 1}, {x86.AJPC, 0}}, // next == b.Succs[1] +} +var nefJumps = [2][2]floatingEQNEJump{ + {{x86.AJNE, 0}, {x86.AJPC, 1}}, // next == b.Succs[0] + {{x86.AJNE, 0}, {x86.AJPS, 0}}, // next == b.Succs[1] +} + +func oneFPJump(b *ssa.Block, jumps *floatingEQNEJump, likely ssa.BranchPrediction, branches []branch) []branch { + p := Prog(jumps.jump) + p.To.Type = obj.TYPE_BRANCH + to := jumps.index + branches = append(branches, branch{p, b.Succs[to]}) + if to == 1 { + likely = -likely + } + // liblink reorders the instruction stream as it sees fit. + // Pass along what we know so liblink can make use of it. + // TODO: Once we've fully switched to SSA, + // make liblink leave our output alone. + switch likely { + case ssa.BranchUnlikely: + p.From.Type = obj.TYPE_CONST + p.From.Offset = 0 + case ssa.BranchLikely: + p.From.Type = obj.TYPE_CONST + p.From.Offset = 1 + } + return branches +} + +func genFPJump(s *genState, b, next *ssa.Block, jumps *[2][2]floatingEQNEJump) { + likely := b.Likely + switch next { + case b.Succs[0]: + s.branches = oneFPJump(b, &jumps[0][0], likely, s.branches) + s.branches = oneFPJump(b, &jumps[0][1], likely, s.branches) + case b.Succs[1]: + s.branches = oneFPJump(b, &jumps[1][0], likely, s.branches) + s.branches = oneFPJump(b, &jumps[1][1], likely, s.branches) + default: + s.branches = oneFPJump(b, &jumps[1][0], likely, s.branches) + s.branches = oneFPJump(b, &jumps[1][1], likely, s.branches) + q := Prog(obj.AJMP) + q.To.Type = obj.TYPE_BRANCH + s.branches = append(s.branches, branch{q, b.Succs[1]}) + } +} + +func (s *genState) genBlock(b, next *ssa.Block) { + lineno = b.Line + + // after a panic call, don't emit any branch code + if len(b.Values) > 0 { + switch b.Values[len(b.Values)-1].Op { + case ssa.OpAMD64LoweredPanicNilCheck, + ssa.OpAMD64LoweredPanicIndexCheck, + ssa.OpAMD64LoweredPanicSliceCheck: + return + } + } + + switch b.Kind { + case ssa.BlockPlain: + if b.Succs[0] != next { + p := Prog(obj.AJMP) + p.To.Type = obj.TYPE_BRANCH + s.branches = append(s.branches, branch{p, b.Succs[0]}) + } + case ssa.BlockExit: + case ssa.BlockRet: - if Hasdefer != 0 { ++ if hasdefer { + s.deferReturn() + } + Prog(obj.ARET) + case ssa.BlockCall: + if b.Succs[0] != next { + p := Prog(obj.AJMP) + p.To.Type = obj.TYPE_BRANCH + s.branches = append(s.branches, branch{p, b.Succs[0]}) + } + + case ssa.BlockAMD64EQF: + genFPJump(s, b, next, &eqfJumps) + + case ssa.BlockAMD64NEF: + genFPJump(s, b, next, &nefJumps) + + case ssa.BlockAMD64EQ, ssa.BlockAMD64NE, + ssa.BlockAMD64LT, ssa.BlockAMD64GE, + ssa.BlockAMD64LE, ssa.BlockAMD64GT, + ssa.BlockAMD64ULT, ssa.BlockAMD64UGT, + ssa.BlockAMD64ULE, ssa.BlockAMD64UGE: + jmp := blockJump[b.Kind] + likely := b.Likely + var p *obj.Prog + switch next { + case b.Succs[0]: + p = Prog(jmp.invasm) + likely *= -1 + p.To.Type = obj.TYPE_BRANCH + s.branches = append(s.branches, branch{p, b.Succs[1]}) + case b.Succs[1]: + p = Prog(jmp.asm) + p.To.Type = obj.TYPE_BRANCH + s.branches = append(s.branches, branch{p, b.Succs[0]}) + default: + p = Prog(jmp.asm) + p.To.Type = obj.TYPE_BRANCH + s.branches = append(s.branches, branch{p, b.Succs[0]}) + q := Prog(obj.AJMP) + q.To.Type = obj.TYPE_BRANCH + s.branches = append(s.branches, branch{q, b.Succs[1]}) + } + + // liblink reorders the instruction stream as it sees fit. + // Pass along what we know so liblink can make use of it. + // TODO: Once we've fully switched to SSA, + // make liblink leave our output alone. + switch likely { + case ssa.BranchUnlikely: + p.From.Type = obj.TYPE_CONST + p.From.Offset = 0 + case ssa.BranchLikely: + p.From.Type = obj.TYPE_CONST + p.From.Offset = 1 + } + + default: + b.Unimplementedf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString()) + } +} + +func (s *genState) deferReturn() { + // Deferred calls will appear to be returning to + // the CALL deferreturn(SB) that we are about to emit. + // However, the stack trace code will show the line + // of the instruction byte before the return PC. + // To avoid that being an unrelated instruction, + // insert an actual hardware NOP that will have the right line number. + // This is different from obj.ANOP, which is a virtual no-op + // that doesn't make it into the instruction stream. + s.deferTarget = Pc + Thearch.Ginsnop() + p := Prog(obj.ACALL) + p.To.Type = obj.TYPE_MEM + p.To.Name = obj.NAME_EXTERN + p.To.Sym = Linksym(Deferreturn.Sym) +} + +// addAux adds the offset in the aux fields (AuxInt and Aux) of v to a. +func addAux(a *obj.Addr, v *ssa.Value) { + if a.Type != obj.TYPE_MEM { + v.Fatalf("bad addAux addr %s", a) + } + // add integer offset + a.Offset += v.AuxInt + + // If no additional symbol offset, we're done. + if v.Aux == nil { + return + } + // Add symbol's offset from its base register. + switch sym := v.Aux.(type) { + case *ssa.ExternSymbol: + a.Name = obj.NAME_EXTERN + a.Sym = Linksym(sym.Sym.(*Sym)) + case *ssa.ArgSymbol: + n := sym.Node.(*Node) + a.Name = obj.NAME_PARAM + a.Node = n + a.Sym = Linksym(n.Orig.Sym) + a.Offset += n.Xoffset // TODO: why do I have to add this here? I don't for auto variables. + case *ssa.AutoSymbol: + n := sym.Node.(*Node) + a.Name = obj.NAME_AUTO + a.Node = n + a.Sym = Linksym(n.Sym) + default: + v.Fatalf("aux in %s not implemented %#v", v, v.Aux) + } +} + +// extendIndex extends v to a full pointer width. +func (s *state) extendIndex(v *ssa.Value) *ssa.Value { + size := v.Type.Size() + if size == s.config.PtrSize { + return v + } + if size > s.config.PtrSize { + // TODO: truncate 64-bit indexes on 32-bit pointer archs. We'd need to test + // the high word and branch to out-of-bounds failure if it is not 0. + s.Unimplementedf("64->32 index truncation not implemented") + return v + } + + // Extend value to the required size + var op ssa.Op + if v.Type.IsSigned() { + switch 10*size + s.config.PtrSize { + case 14: + op = ssa.OpSignExt8to32 + case 18: + op = ssa.OpSignExt8to64 + case 24: + op = ssa.OpSignExt16to32 + case 28: + op = ssa.OpSignExt16to64 + case 48: + op = ssa.OpSignExt32to64 + default: + s.Fatalf("bad signed index extension %s", v.Type) + } + } else { + switch 10*size + s.config.PtrSize { + case 14: + op = ssa.OpZeroExt8to32 + case 18: + op = ssa.OpZeroExt8to64 + case 24: + op = ssa.OpZeroExt16to32 + case 28: + op = ssa.OpZeroExt16to64 + case 48: + op = ssa.OpZeroExt32to64 + default: + s.Fatalf("bad unsigned index extension %s", v.Type) + } + } + return s.newValue1(op, Types[TUINTPTR], v) +} + +// ssaRegToReg maps ssa register numbers to obj register numbers. +var ssaRegToReg = [...]int16{ + x86.REG_AX, + x86.REG_CX, + x86.REG_DX, + x86.REG_BX, + x86.REG_SP, + x86.REG_BP, + x86.REG_SI, + x86.REG_DI, + x86.REG_R8, + x86.REG_R9, + x86.REG_R10, + x86.REG_R11, + x86.REG_R12, + x86.REG_R13, + x86.REG_R14, + x86.REG_R15, + x86.REG_X0, + x86.REG_X1, + x86.REG_X2, + x86.REG_X3, + x86.REG_X4, + x86.REG_X5, + x86.REG_X6, + x86.REG_X7, + x86.REG_X8, + x86.REG_X9, + x86.REG_X10, + x86.REG_X11, + x86.REG_X12, + x86.REG_X13, + x86.REG_X14, + x86.REG_X15, + 0, // SB isn't a real register. We fill an Addr.Reg field with 0 in this case. + // TODO: arch-dependent +} + +// regMoveAMD64 returns the register->register move opcode for the given width. +// TODO: generalize for all architectures? +func regMoveAMD64(width int64) int { + switch width { + case 1: + return x86.AMOVB + case 2: + return x86.AMOVW + case 4: + return x86.AMOVL + case 8: + return x86.AMOVQ + default: + panic("bad int register width") + } +} + +func regMoveByTypeAMD64(t ssa.Type) int { + width := t.Size() + if t.IsFloat() { + switch width { + case 4: + return x86.AMOVSS + case 8: + return x86.AMOVSD + default: + panic("bad float register width") + } + } else { + switch width { + case 1: + return x86.AMOVB + case 2: + return x86.AMOVW + case 4: + return x86.AMOVL + case 8: + return x86.AMOVQ + default: + panic("bad int register width") + } + } + + panic("bad register type") +} + +// regnum returns the register (in cmd/internal/obj numbering) to +// which v has been allocated. Panics if v is not assigned to a +// register. +// TODO: Make this panic again once it stops happening routinely. +func regnum(v *ssa.Value) int16 { + reg := v.Block.Func.RegAlloc[v.ID] + if reg == nil { + v.Unimplementedf("nil regnum for value: %s\n%s\n", v.LongString(), v.Block.Func) + return 0 + } + return ssaRegToReg[reg.(*ssa.Register).Num] +} + +// autoVar returns a *Node representing the auto variable assigned to v. +func autoVar(v *ssa.Value) *Node { + return v.Block.Func.RegAlloc[v.ID].(*ssa.LocalSlot).N.(*Node) +} + +// ssaExport exports a bunch of compiler services for the ssa backend. +type ssaExport struct { + log bool + unimplemented bool + mustImplement bool +} + +func (s *ssaExport) TypeBool() ssa.Type { return Types[TBOOL] } +func (s *ssaExport) TypeInt8() ssa.Type { return Types[TINT8] } +func (s *ssaExport) TypeInt16() ssa.Type { return Types[TINT16] } +func (s *ssaExport) TypeInt32() ssa.Type { return Types[TINT32] } +func (s *ssaExport) TypeInt64() ssa.Type { return Types[TINT64] } +func (s *ssaExport) TypeUInt8() ssa.Type { return Types[TUINT8] } +func (s *ssaExport) TypeUInt16() ssa.Type { return Types[TUINT16] } +func (s *ssaExport) TypeUInt32() ssa.Type { return Types[TUINT32] } +func (s *ssaExport) TypeUInt64() ssa.Type { return Types[TUINT64] } +func (s *ssaExport) TypeFloat32() ssa.Type { return Types[TFLOAT32] } +func (s *ssaExport) TypeFloat64() ssa.Type { return Types[TFLOAT64] } +func (s *ssaExport) TypeInt() ssa.Type { return Types[TINT] } +func (s *ssaExport) TypeUintptr() ssa.Type { return Types[TUINTPTR] } +func (s *ssaExport) TypeString() ssa.Type { return Types[TSTRING] } +func (s *ssaExport) TypeBytePtr() ssa.Type { return Ptrto(Types[TUINT8]) } + +// StringData returns a symbol (a *Sym wrapped in an interface) which +// is the data component of a global string constant containing s. +func (*ssaExport) StringData(s string) interface{} { + // TODO: is idealstring correct? It might not matter... + _, data := stringsym(s) + return &ssa.ExternSymbol{Typ: idealstring, Sym: data} +} + +func (e *ssaExport) Auto(t ssa.Type) fmt.Stringer { + n := temp(t.(*Type)) // Note: adds new auto to Curfn.Func.Dcl list + e.mustImplement = true // This modifies the input to SSA, so we want to make sure we succeed from here! + return n +} + +// Log logs a message from the compiler. +func (e *ssaExport) Logf(msg string, args ...interface{}) { + // If e was marked as unimplemented, anything could happen. Ignore. + if e.log && !e.unimplemented { + fmt.Printf(msg, args...) + } +} + +// Fatal reports a compiler error and exits. +func (e *ssaExport) Fatalf(msg string, args ...interface{}) { + // If e was marked as unimplemented, anything could happen. Ignore. + if !e.unimplemented { - Fatal(msg, args...) ++ Fatalf(msg, args...) + } +} + +// Unimplemented reports that the function cannot be compiled. +// It will be removed once SSA work is complete. +func (e *ssaExport) Unimplementedf(msg string, args ...interface{}) { + if e.mustImplement { - Fatal(msg, args...) ++ Fatalf(msg, args...) + } + const alwaysLog = false // enable to calculate top unimplemented features + if !e.unimplemented && (e.log || alwaysLog) { + // first implementation failure, print explanation + fmt.Printf("SSA unimplemented: "+msg+"\n", args...) + } + e.unimplemented = true +}