cmd/compile: remove backend's "scratch mem" support

This CL rebases CL 273987 on top of master with @mdempsky's permission.

The last (only?) use for this feature was 387 support, which was
removed in golang.org/cl/258957.

Change-Id: I4f79fee8d0c336c9b6082bcd5eb6ece52c032dc0
Reviewed-on: https://go-review.googlesource.com/c/go/+/292893
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

diff --git a/src/cmd/compile/internal/ssa/config.go b/src/cmd/compile/internal/ssa/config.go
index c29bc8fae6f70bf0a7cca248b2730f68f40bc586..f3a3a88a66583b121fe8525063532f0f7971fd84 100644 (file)
--- a/src/cmd/compile/internal/ssa/config.go
+++ b/src/cmd/compile/internal/ssa/config.go
@@ -42,7 +42,6 @@ type Config struct {
        useHmul        bool          // Use optimizations that need Hmul* operations
        SoftFloat      bool          //
        Race           bool          // race detector enabled
-       NeedsFpScratch bool          // No direct move between GP and FP register sets
        BigEndian      bool          //
        UseFMA         bool          // Use hardware FMA operation
 }

diff --git a/src/cmd/compile/internal/ssa/gen/386Ops.go b/src/cmd/compile/internal/ssa/gen/386Ops.go
index 737b99c3716c8894f45b764419f7d1040cdf1e78..2b7185e537ec49bae4e0aed594daf2b74f774b8a 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/386Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/386Ops.go
@@ -146,14 +146,14 @@ func init() {
 
        var _386ops = []opData{
                // fp ops
-               {name: "ADDSS", argLength: 2, reg: fp21, asm: "ADDSS", commutative: true, resultInArg0: true, usesScratch: true}, // fp32 add
-               {name: "ADDSD", argLength: 2, reg: fp21, asm: "ADDSD", commutative: true, resultInArg0: true},                    // fp64 add
-               {name: "SUBSS", argLength: 2, reg: fp21, asm: "SUBSS", resultInArg0: true, usesScratch: true},                    // fp32 sub
-               {name: "SUBSD", argLength: 2, reg: fp21, asm: "SUBSD", resultInArg0: true},                                       // fp64 sub
-               {name: "MULSS", argLength: 2, reg: fp21, asm: "MULSS", commutative: true, resultInArg0: true, usesScratch: true}, // fp32 mul
-               {name: "MULSD", argLength: 2, reg: fp21, asm: "MULSD", commutative: true, resultInArg0: true},                    // fp64 mul
-               {name: "DIVSS", argLength: 2, reg: fp21, asm: "DIVSS", resultInArg0: true, usesScratch: true},                    // fp32 div
-               {name: "DIVSD", argLength: 2, reg: fp21, asm: "DIVSD", resultInArg0: true},                                       // fp64 div
+               {name: "ADDSS", argLength: 2, reg: fp21, asm: "ADDSS", commutative: true, resultInArg0: true}, // fp32 add
+               {name: "ADDSD", argLength: 2, reg: fp21, asm: "ADDSD", commutative: true, resultInArg0: true}, // fp64 add
+               {name: "SUBSS", argLength: 2, reg: fp21, asm: "SUBSS", resultInArg0: true},                    // fp32 sub
+               {name: "SUBSD", argLength: 2, reg: fp21, asm: "SUBSD", resultInArg0: true},                    // fp64 sub
+               {name: "MULSS", argLength: 2, reg: fp21, asm: "MULSS", commutative: true, resultInArg0: true}, // fp32 mul
+               {name: "MULSD", argLength: 2, reg: fp21, asm: "MULSD", commutative: true, resultInArg0: true}, // fp64 mul
+               {name: "DIVSS", argLength: 2, reg: fp21, asm: "DIVSS", resultInArg0: true},                    // fp32 div
+               {name: "DIVSD", argLength: 2, reg: fp21, asm: "DIVSD", resultInArg0: true},                    // fp64 div
 
                {name: "MOVSSload", argLength: 2, reg: fpload, asm: "MOVSS", aux: "SymOff", faultOnNilArg0: true, symEffect: "Read"}, // fp32 load
                {name: "MOVSDload", argLength: 2, reg: fpload, asm: "MOVSD", aux: "SymOff", faultOnNilArg0: true, symEffect: "Read"}, // fp64 load
@@ -246,8 +246,8 @@ func init() {
                {name: "CMPWconstload", argLength: 2, reg: gp0flagsLoad, asm: "CMPW", aux: "SymValAndOff", typ: "Flags", symEffect: "Read", faultOnNilArg0: true},
                {name: "CMPBconstload", argLength: 2, reg: gp0flagsLoad, asm: "CMPB", aux: "SymValAndOff", typ: "Flags", symEffect: "Read", faultOnNilArg0: true},
 
-               {name: "UCOMISS", argLength: 2, reg: fp2flags, asm: "UCOMISS", typ: "Flags", usesScratch: true}, // arg0 compare to arg1, f32
-               {name: "UCOMISD", argLength: 2, reg: fp2flags, asm: "UCOMISD", typ: "Flags", usesScratch: true}, // arg0 compare to arg1, f64
+               {name: "UCOMISS", argLength: 2, reg: fp2flags, asm: "UCOMISS", typ: "Flags"}, // arg0 compare to arg1, f32
+               {name: "UCOMISD", argLength: 2, reg: fp2flags, asm: "UCOMISD", typ: "Flags"}, // arg0 compare to arg1, f64
 
                {name: "TESTL", argLength: 2, reg: gp2flags, commutative: true, asm: "TESTL", typ: "Flags"}, // (arg0 & arg1) compare to 0
                {name: "TESTW", argLength: 2, reg: gp2flags, commutative: true, asm: "TESTW", typ: "Flags"}, // (arg0 & arg1) compare to 0
@@ -341,12 +341,12 @@ func init() {
 
                {name: "MOVLconst", reg: gp01, asm: "MOVL", typ: "UInt32", aux: "Int32", rematerializeable: true}, // 32 low bits of auxint
 
-               {name: "CVTTSD2SL", argLength: 1, reg: fpgp, asm: "CVTTSD2SL", usesScratch: true}, // convert float64 to int32
-               {name: "CVTTSS2SL", argLength: 1, reg: fpgp, asm: "CVTTSS2SL", usesScratch: true}, // convert float32 to int32
-               {name: "CVTSL2SS", argLength: 1, reg: gpfp, asm: "CVTSL2SS", usesScratch: true},   // convert int32 to float32
-               {name: "CVTSL2SD", argLength: 1, reg: gpfp, asm: "CVTSL2SD", usesScratch: true},   // convert int32 to float64
-               {name: "CVTSD2SS", argLength: 1, reg: fp11, asm: "CVTSD2SS", usesScratch: true},   // convert float64 to float32
-               {name: "CVTSS2SD", argLength: 1, reg: fp11, asm: "CVTSS2SD"},                      // convert float32 to float64
+               {name: "CVTTSD2SL", argLength: 1, reg: fpgp, asm: "CVTTSD2SL"}, // convert float64 to int32
+               {name: "CVTTSS2SL", argLength: 1, reg: fpgp, asm: "CVTTSS2SL"}, // convert float32 to int32
+               {name: "CVTSL2SS", argLength: 1, reg: gpfp, asm: "CVTSL2SS"},   // convert int32 to float32
+               {name: "CVTSL2SD", argLength: 1, reg: gpfp, asm: "CVTSL2SD"},   // convert int32 to float64
+               {name: "CVTSD2SS", argLength: 1, reg: fp11, asm: "CVTSD2SS"},   // convert float64 to float32
+               {name: "CVTSS2SD", argLength: 1, reg: fp11, asm: "CVTSS2SD"},   // convert float32 to float64
 
                {name: "PXOR", argLength: 2, reg: fp21, asm: "PXOR", commutative: true, resultInArg0: true}, // exclusive or, applied to X regs for float negation.
 

diff --git a/src/cmd/compile/internal/ssa/gen/main.go b/src/cmd/compile/internal/ssa/gen/main.go
index dfa146a28ae2579451477e0fc25b415196a8583e..e7a4ef0629653c2272c33387fdc467f4010c7bd1 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/main.go
+++ b/src/cmd/compile/internal/ssa/gen/main.go
@@ -63,7 +63,6 @@ type opData struct {
        nilCheck          bool   // this op is a nil check on arg0
        faultOnNilArg0    bool   // this op will fault if arg0 is nil (and aux encodes a small offset)
        faultOnNilArg1    bool   // this op will fault if arg1 is nil (and aux encodes a small offset)
-       usesScratch       bool   // this op requires scratch memory space
        hasSideEffects    bool   // for "reasons", not to be eliminated.  E.g., atomic store, #19182.
        zeroWidth         bool   // op never translates into any machine code. example: copy, which may sometimes translate to machine code, is not zero-width.
        unsafePoint       bool   // this op is an unsafe point, i.e. not safe for async preemption
@@ -320,9 +319,6 @@ func genOp() {
                                        log.Fatalf("faultOnNilArg1 with aux %s not allowed", v.aux)
                                }
                        }
-                       if v.usesScratch {
-                               fmt.Fprintln(w, "usesScratch: true,")
-                       }
                        if v.hasSideEffects {
                                fmt.Fprintln(w, "hasSideEffects: true,")
                        }
@@ -404,8 +400,6 @@ func genOp() {
        // generate op string method
        fmt.Fprintln(w, "func (o Op) String() string {return opcodeTable[o].name }")
 
-       fmt.Fprintln(w, "func (o Op) UsesScratch() bool { return opcodeTable[o].usesScratch }")
-
        fmt.Fprintln(w, "func (o Op) SymEffect() SymEffect { return opcodeTable[o].symEffect }")
        fmt.Fprintln(w, "func (o Op) IsCall() bool { return opcodeTable[o].call }")
        fmt.Fprintln(w, "func (o Op) HasSideEffects() bool { return opcodeTable[o].hasSideEffects }")

diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go
index ccfed93475ddb78e6333e6bbac9fe5bfa12ab980..e4087bd02128d7699c99850b18d51c197d602e4f 100644 (file)
--- a/src/cmd/compile/internal/ssa/opGen.go
+++ b/src/cmd/compile/internal/ssa/opGen.go
@@ -2912,7 +2912,6 @@ var opcodeTable = [...]opInfo{
                argLen:       2,
                commutative:  true,
                resultInArg0: true,
-               usesScratch:  true,
                asm:          x86.AADDSS,
                reg: regInfo{
                        inputs: []inputInfo{
@@ -2944,7 +2943,6 @@ var opcodeTable = [...]opInfo{
                name:         "SUBSS",
                argLen:       2,
                resultInArg0: true,
-               usesScratch:  true,
                asm:          x86.ASUBSS,
                reg: regInfo{
                        inputs: []inputInfo{
@@ -2976,7 +2974,6 @@ var opcodeTable = [...]opInfo{
                argLen:       2,
                commutative:  true,
                resultInArg0: true,
-               usesScratch:  true,
                asm:          x86.AMULSS,
                reg: regInfo{
                        inputs: []inputInfo{
@@ -3008,7 +3005,6 @@ var opcodeTable = [...]opInfo{
                name:         "DIVSS",
                argLen:       2,
                resultInArg0: true,
-               usesScratch:  true,
                asm:          x86.ADIVSS,
                reg: regInfo{
                        inputs: []inputInfo{
@@ -4072,10 +4068,9 @@ var opcodeTable = [...]opInfo{
                },
        },
        {
-               name:        "UCOMISS",
-               argLen:      2,
-               usesScratch: true,
-               asm:         x86.AUCOMISS,
+               name:   "UCOMISS",
+               argLen: 2,
+               asm:    x86.AUCOMISS,
                reg: regInfo{
                        inputs: []inputInfo{
                                {0, 65280}, // X0 X1 X2 X3 X4 X5 X6 X7
@@ -4084,10 +4079,9 @@ var opcodeTable = [...]opInfo{
                },
        },
        {
-               name:        "UCOMISD",
-               argLen:      2,
-               usesScratch: true,
-               asm:         x86.AUCOMISD,
+               name:   "UCOMISD",
+               argLen: 2,
+               asm:    x86.AUCOMISD,
                reg: regInfo{
                        inputs: []inputInfo{
                                {0, 65280}, // X0 X1 X2 X3 X4 X5 X6 X7
@@ -5027,10 +5021,9 @@ var opcodeTable = [...]opInfo{
                },
        },
        {
-               name:        "CVTTSD2SL",
-               argLen:      1,
-               usesScratch: true,
-               asm:         x86.ACVTTSD2SL,
+               name:   "CVTTSD2SL",
+               argLen: 1,
+               asm:    x86.ACVTTSD2SL,
                reg: regInfo{
                        inputs: []inputInfo{
                                {0, 65280}, // X0 X1 X2 X3 X4 X5 X6 X7
@@ -5041,10 +5034,9 @@ var opcodeTable = [...]opInfo{
                },
        },
        {
-               name:        "CVTTSS2SL",
-               argLen:      1,
-               usesScratch: true,
-               asm:         x86.ACVTTSS2SL,
+               name:   "CVTTSS2SL",
+               argLen: 1,
+               asm:    x86.ACVTTSS2SL,
                reg: regInfo{
                        inputs: []inputInfo{
                                {0, 65280}, // X0 X1 X2 X3 X4 X5 X6 X7
@@ -5055,10 +5047,9 @@ var opcodeTable = [...]opInfo{
                },
        },
        {
-               name:        "CVTSL2SS",
-               argLen:      1,
-               usesScratch: true,
-               asm:         x86.ACVTSL2SS,
+               name:   "CVTSL2SS",
+               argLen: 1,
+               asm:    x86.ACVTSL2SS,
                reg: regInfo{
                        inputs: []inputInfo{
                                {0, 239}, // AX CX DX BX BP SI DI
@@ -5069,10 +5060,9 @@ var opcodeTable = [...]opInfo{
                },
        },
        {
-               name:        "CVTSL2SD",
-               argLen:      1,
-               usesScratch: true,
-               asm:         x86.ACVTSL2SD,
+               name:   "CVTSL2SD",
+               argLen: 1,
+               asm:    x86.ACVTSL2SD,
                reg: regInfo{
                        inputs: []inputInfo{
                                {0, 239}, // AX CX DX BX BP SI DI
@@ -5083,10 +5073,9 @@ var opcodeTable = [...]opInfo{
                },
        },
        {
-               name:        "CVTSD2SS",
-               argLen:      1,
-               usesScratch: true,
-               asm:         x86.ACVTSD2SS,
+               name:   "CVTSD2SS",
+               argLen: 1,
+               asm:    x86.ACVTSD2SS,
                reg: regInfo{
                        inputs: []inputInfo{
                                {0, 65280}, // X0 X1 X2 X3 X4 X5 X6 X7
@@ -36128,7 +36117,6 @@ var opcodeTable = [...]opInfo{
 func (o Op) Asm() obj.As          { return opcodeTable[o].asm }
 func (o Op) Scale() int16         { return int16(opcodeTable[o].scale) }
 func (o Op) String() string       { return opcodeTable[o].name }
-func (o Op) UsesScratch() bool    { return opcodeTable[o].usesScratch }
 func (o Op) SymEffect() SymEffect { return opcodeTable[o].symEffect }
 func (o Op) IsCall() bool         { return opcodeTable[o].call }
 func (o Op) HasSideEffects() bool { return opcodeTable[o].hasSideEffects }

diff --git a/src/cmd/compile/internal/ssagen/pgen.go b/src/cmd/compile/internal/ssagen/pgen.go
index 40f07a8d45aad7ada9addfb6681df209450052ad..25b09e1f5da1a0117ee81435233e3ed9006ac2ed 100644 (file)
--- a/src/cmd/compile/internal/ssagen/pgen.go
+++ b/src/cmd/compile/internal/ssagen/pgen.go
@@ -15,7 +15,6 @@ import (
        "cmd/compile/internal/ir"
        "cmd/compile/internal/objw"
        "cmd/compile/internal/ssa"
-       "cmd/compile/internal/typecheck"
        "cmd/compile/internal/types"
        "cmd/internal/obj"
        "cmd/internal/objabi"
@@ -90,7 +89,6 @@ func (s *ssafn) AllocFrame(f *ssa.Func) {
                }
        }
 
-       scratchUsed := false
        for _, b := range f.Blocks {
                for _, v := range b.Values {
                        if n, ok := v.Aux.(*ir.Name); ok {
@@ -104,17 +102,9 @@ func (s *ssafn) AllocFrame(f *ssa.Func) {
                                        n.SetUsed(true)
                                }
                        }
-                       if !scratchUsed {
-                               scratchUsed = v.Op.UsesScratch()
-                       }
-
                }
        }
 
-       if f.Config.NeedsFpScratch && scratchUsed {
-               s.scratchFpMem = typecheck.TempAt(src.NoXPos, s.curfn, types.Types[types.TUINT64])
-       }
-
        sort.Sort(byStackVar(fn.Dcl))
 
        // Reassign stack offsets of the locals that are used.

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index e13ca90d33ffd6520f65369092594043fad07296..cfc54ae0ab45ecf46969d31144d7cc9f47dd5b07 100644 (file)
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -6282,9 +6282,6 @@ type State struct {
        // bstart remembers where each block starts (indexed by block ID)
        bstart []*obj.Prog
 
-       // Some architectures require a 64-bit temporary for FP-related register shuffling. Examples include PPC and Sparc V8.
-       ScratchFpMem *ir.Name
-
        maxarg int64 // largest frame size for arguments to calls made by the function
 
        // Map from GC safe points to liveness index, generated by
@@ -6398,8 +6395,6 @@ func genssa(f *ssa.Func, pp *objw.Progs) {
                progToBlock[s.pp.Next] = f.Blocks[0]
        }
 
-       s.ScratchFpMem = e.scratchFpMem
-
        if base.Ctxt.Flag_locationlists {
                if cap(f.Cache.ValueToProgAfter) < f.NumValues() {
                        f.Cache.ValueToProgAfter = make([]*obj.Prog, f.NumValues())
@@ -6948,17 +6943,6 @@ func AddrAuto(a *obj.Addr, v *ssa.Value) {
        }
 }
 
-func (s *State) AddrScratch(a *obj.Addr) {
-       if s.ScratchFpMem == nil {
-               panic("no scratch memory available; forgot to declare usesScratch for Op?")
-       }
-       a.Type = obj.TYPE_MEM
-       a.Name = obj.NAME_AUTO
-       a.Sym = s.ScratchFpMem.Linksym()
-       a.Reg = int16(Arch.REGSP)
-       a.Offset = s.ScratchFpMem.Offset_
-}
-
 // Call returns a new CALL instruction for the SSA value v.
 // It uses PrepareCall to prepare the call.
 func (s *State) Call(v *ssa.Value) *obj.Prog {
@@ -7061,12 +7045,11 @@ func fieldIdx(n *ir.SelectorExpr) int {
 // ssafn holds frontend information about a function that the backend is processing.
 // It also exports a bunch of compiler services for the ssa backend.
 type ssafn struct {
-       curfn        *ir.Func
-       strings      map[string]*obj.LSym // map from constant string to data symbols
-       scratchFpMem *ir.Name             // temp for floating point register / memory moves on some architectures
-       stksize      int64                // stack size for current frame
-       stkptrsize   int64                // prefix of stack containing pointers
-       log          bool                 // print ssa debug to the stdout
+       curfn      *ir.Func
+       strings    map[string]*obj.LSym // map from constant string to data symbols
+       stksize    int64                // stack size for current frame
+       stkptrsize int64                // prefix of stack containing pointers
+       log        bool                 // print ssa debug to the stdout
 }
 
 // StringData returns a symbol which