]> Cypherpunks repositories - gostls13.git/commitdiff
cmd/asm: improve argument to obj.Prog assignment on PPC64
authorPaul E. Murphy <murp@ibm.com>
Thu, 1 Sep 2022 14:23:49 +0000 (09:23 -0500)
committerPaul Murphy <murp@ibm.com>
Wed, 7 Sep 2022 20:53:33 +0000 (20:53 +0000)
These can be simplified with the knowledge of how arguments are
assigned to obj.Prog objects on PPC64. If the argument is not
a register type, the Reg argument (a2 in optab) of obj.Prog is
not used, and those arguments are placed into RestArgs (a3, a4, a5
in optab).

This relaxes the special case handling enforced by IsPPC64RLD and
IsPPC64ISEL. Instead, arguments are assigned as noted above, and
incorrect usage of such opcodes is checked by optab rules, not by
the assembler front-end.

Likewise, add support for handling 6 argument opcodes, these do
not exist today, but will be added with ISA 3.1 (Power10).

Finally, to maintain backwards compatibility, some 4-arg opcodes
whose middle arguments are a register and immediate, could swap
these arguments and generate identical machine code. This likely
wasn't intended, but is possible. These are explicitly fixed up
in the backend, and the asm tests are extended to check these.

Change-Id: I5f8190212427dfe8e6f062185bfefb5fa4fd0e75
Reviewed-on: https://go-review.googlesource.com/c/go/+/427516
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
src/cmd/asm/internal/arch/ppc64.go
src/cmd/asm/internal/asm/asm.go
src/cmd/asm/internal/asm/testdata/ppc64.s
src/cmd/internal/obj/ppc64/obj9.go

index 76fe1d65250a43b912665f849bd68ef2cdda9a0a..98a2bfedfdd0c54e2d3e7d37f4dafaf518a8eabe 100644 (file)
@@ -21,28 +21,6 @@ func jumpPPC64(word string) bool {
        return false
 }
 
-// IsPPC64RLD reports whether the op (as defined by an ppc64.A* constant) is
-// one of the RLD-like instructions that require special handling.
-// The FMADD-like instructions behave similarly.
-func IsPPC64RLD(op obj.As) bool {
-       switch op {
-       case ppc64.ARLDC, ppc64.ARLDCCC, ppc64.ARLDCL, ppc64.ARLDCLCC,
-               ppc64.ARLDCR, ppc64.ARLDCRCC, ppc64.ARLDMI, ppc64.ARLDMICC,
-               ppc64.ARLWMI, ppc64.ARLWMICC, ppc64.ARLWNM, ppc64.ARLWNMCC:
-               return true
-       case ppc64.AFMADD, ppc64.AFMADDCC, ppc64.AFMADDS, ppc64.AFMADDSCC,
-               ppc64.AFMSUB, ppc64.AFMSUBCC, ppc64.AFMSUBS, ppc64.AFMSUBSCC,
-               ppc64.AFNMADD, ppc64.AFNMADDCC, ppc64.AFNMADDS, ppc64.AFNMADDSCC,
-               ppc64.AFNMSUB, ppc64.AFNMSUBCC, ppc64.AFNMSUBS, ppc64.AFNMSUBSCC:
-               return true
-       }
-       return false
-}
-
-func IsPPC64ISEL(op obj.As) bool {
-       return op == ppc64.AISEL
-}
-
 // IsPPC64CMP reports whether the op (as defined by an ppc64.A* constant) is
 // one of the CMP instructions that require special handling.
 func IsPPC64CMP(op obj.As) bool {
index cfd1f4c70732bd82abfb9a81506d070ea7da5be4..050a4f013cce39ab4f5b33d951d326ce54782191 100644 (file)
@@ -727,23 +727,17 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
                                prog.To = a[1]
                                break
                        }
-                       // Arithmetic. Choices are:
-                       // reg reg reg
-                       // imm reg reg
-                       // reg imm reg
-                       // If the immediate is the middle argument, use From3.
+
+                       prog.From = a[0]
+                       prog.To = a[2]
+
+                       // If the second argument is not a register argument, it must be
+                       // passed RestArgs/SetFrom3
                        switch a[1].Type {
                        case obj.TYPE_REG:
-                               prog.From = a[0]
                                prog.Reg = p.getRegister(prog, op, &a[1])
-                               prog.To = a[2]
-                       case obj.TYPE_CONST:
-                               prog.From = a[0]
-                               prog.SetFrom3(a[1])
-                               prog.To = a[2]
                        default:
-                               p.errorf("invalid addressing modes for %s instruction", op)
-                               return
+                               prog.SetFrom3(a[1])
                        }
                case sys.RISCV64:
                        // RISCV64 instructions with one input and two outputs.
@@ -810,41 +804,18 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
                        break
                }
                if p.arch.Family == sys.PPC64 {
-                       if arch.IsPPC64RLD(op) {
-                               prog.From = a[0]
-                               prog.Reg = p.getRegister(prog, op, &a[1])
-                               prog.SetFrom3(a[2])
-                               prog.To = a[3]
-                               break
-                       } else if arch.IsPPC64ISEL(op) {
-                               // ISEL BC,RB,RA,RT becomes isel rt,ra,rb,bc
-                               prog.SetFrom3(a[2])                       // ra
-                               prog.From = a[0]                          // bc
-                               prog.Reg = p.getRegister(prog, op, &a[1]) // rb
-                               prog.To = a[3]                            // rt
-                               break
-                       }
-                       // Else, it is a VA-form instruction
-                       // reg reg reg reg
-                       // imm reg reg reg
-                       // Or a VX-form instruction
-                       // imm imm reg reg
+                       prog.From = a[0]
+                       prog.To = a[3]
+                       // If the second argument is not a register argument, it must be
+                       // passed RestArgs/SetFrom3
                        if a[1].Type == obj.TYPE_REG {
-                               prog.From = a[0]
                                prog.Reg = p.getRegister(prog, op, &a[1])
-                               prog.SetFrom3(a[2])
-                               prog.To = a[3]
-                               break
-                       } else if a[1].Type == obj.TYPE_CONST {
-                               prog.From = a[0]
-                               prog.Reg = p.getRegister(prog, op, &a[2])
-                               prog.SetFrom3(a[1])
-                               prog.To = a[3]
-                               break
+                               prog.SetRestArgs([]obj.Addr{a[2]})
                        } else {
-                               p.errorf("invalid addressing modes for %s instruction", op)
-                               return
+                               // Don't set prog.Reg if a1 isn't a reg arg.
+                               prog.SetRestArgs([]obj.Addr{a[1], a[2]})
                        }
+                       break
                }
                if p.arch.Family == sys.RISCV64 {
                        prog.From = a[0]
@@ -909,6 +880,14 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
                        prog.As = MRC // Both instructions are coded as MRC.
                        break
                }
+               if p.arch.Family == sys.PPC64 {
+                       prog.From = a[0]
+                       // Second arg is always a register type on ppc64.
+                       prog.Reg = p.getRegister(prog, op, &a[1])
+                       prog.SetRestArgs([]obj.Addr{a[2], a[3], a[4]})
+                       prog.To = a[5]
+                       break
+               }
                fallthrough
        default:
                p.errorf("can't handle %s instruction with %d operands", op, len(a))
index 8f03a3afa60bc790c77d140dccf57eb4f80cea0c..2e086056d7e8a044b8d2807c861a1636c69b9213 100644 (file)
@@ -162,6 +162,7 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
        ADD $1234567, R5                // 641f001263ffd6877cbf2a14
        ADD $1234567, R5, R6            // 641f001263ffd6877cdf2a14
        ADDEX R3, R5, $3, R6            // 7cc32f54
+       ADDEX R3, $3, R5, R6            // 7cc32f54
        ADDIS $8, R3                    // 3c630008
        ADDIS $1000, R3, R4             // 3c8303e8
 
@@ -784,7 +785,9 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
        VNCIPHERLAST V1, V2, V3         // 10611549
        VSBOX V1, V2                    // 104105c8
        VSHASIGMAW $1, V1, $15, V2      // 10418e82
+       VSHASIGMAW $1, $15, V1, V2      // 10418e82
        VSHASIGMAD $2, V1, $15, V2      // 104196c2
+       VSHASIGMAD $2, $15, V1, V2      // 104196c2
 
        LXVD2X (R3)(R4), VS1            // 7c241e98
        LXVD2X (R3)(R0), VS1            // 7c201e98
@@ -876,7 +879,11 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
        XXPERM VS1, VS2, VS3            // f06110d0
        XXSLDWI VS1, VS2, $1, VS3       // f0611110
        XXSLDWI V1, V2, $1, V3          // f0611117
+       XXSLDWI V1, $1, V2, V3          // f0611117
        XXSLDWI VS33, VS34, $1, VS35    // f0611117
+       XXSLDWI VS33, $1, VS34, VS35    // f0611117
+       XXPERMDI VS33, VS34, $1, VS35   // f0611157
+       XXPERMDI VS33, $1, VS34, VS35   // f0611157
        XSCVDPSP VS1, VS2               // f0400c24
        XVCVDPSP VS1, VS2               // f0400e24
        XSCVSXDDP VS1, VS2              // f0400de0
index 098f1cd7fece4cd28e865b6037cd771e178fd269..b6b2a8a9a7492f20ebf88a3f702c428999ef2250 100644 (file)
@@ -88,8 +88,8 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
                }
        }
 
-       // Rewrite SUB constants into ADD.
        switch p.As {
+       // Rewrite SUB constants into ADD.
        case ASUBC:
                if p.From.Type == obj.TYPE_CONST {
                        p.From.Offset = -p.From.Offset
@@ -107,7 +107,21 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
                        p.From.Offset = -p.From.Offset
                        p.As = AADD
                }
+
+       // To maintain backwards compatibility, we accept some 4 argument usage of
+       // several opcodes which was likely not intended, but did work. These are not
+       // added to optab to avoid the chance this behavior might be used with newer
+       // instructions.
+       //
+       // Rewrite argument ordering like "ADDEX R3, $3, R4, R5" into
+       //                                "ADDEX R3, R4, $3, R5"
+       case AVSHASIGMAW, AVSHASIGMAD, AADDEX, AXXSLDWI, AXXPERMDI:
+               if len(p.RestArgs) == 2 && p.Reg == 0 && p.RestArgs[0].Addr.Type == obj.TYPE_CONST && p.RestArgs[1].Addr.Type == obj.TYPE_REG {
+                       p.Reg = p.RestArgs[1].Addr.Reg
+                       p.RestArgs = p.RestArgs[:1]
+               }
        }
+
        if c.ctxt.Headtype == objabi.Haix {
                c.rewriteToUseTOC(p)
        } else if c.ctxt.Flag_dynlink {