cmd/compile: guard special register usage with GOEXPERIMENT=regabi

Previously, some special register uses are only guarded with ABI
wrapper generation (-abiwrap). This CL makes it also guarded with
the GOEXPERIMENT. This way we can enable only the wrapper
generation without fully the new ABI, for benchmarking purposes.

Change-Id: I90fc34afa1dc17c9c73e7b06e940e79e4c4bf7f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/295289
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index 4938e4b0e351983f640704df393ba11556a20a28..6944ba7ce7a7045ee83e92892be57f83f2c4a6d4 100644 (file)
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -16,6 +16,7 @@ import (
        "cmd/compile/internal/types"
        "cmd/internal/obj"
        "cmd/internal/obj/x86"
+       "cmd/internal/objabi"
 )
 
 // markMoves marks any MOVXconst ops that need to avoid clobbering flags.
@@ -845,7 +846,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
                if s.ABI != obj.ABIInternal {
                        v.Fatalf("MOVOstorezero can be only used in ABIInternal functions")
                }
-               if !base.Flag.ABIWrap {
+               if !(objabi.Regabi_enabled == 1 && base.Flag.ABIWrap) {
                        // zeroing X15 manually if wrappers are not used
                        opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
                }
@@ -945,7 +946,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
                if s.ABI != obj.ABIInternal {
                        v.Fatalf("MOVOconst can be only used in ABIInternal functions")
                }
-               if !base.Flag.ABIWrap {
+               if !(objabi.Regabi_enabled == 1 && base.Flag.ABIWrap) {
                        // zeroing X15 manually if wrappers are not used
                        opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
                }
@@ -1017,20 +1018,20 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
                // Closure pointer is DX.
                ssagen.CheckLoweredGetClosurePtr(v)
        case ssa.OpAMD64LoweredGetG:
-               if base.Flag.ABIWrap {
+               if objabi.Regabi_enabled == 1 && base.Flag.ABIWrap {
                        v.Fatalf("LoweredGetG should not appear in new ABI")
                }
                r := v.Reg()
                getgFromTLS(s, r)
        case ssa.OpAMD64CALLstatic:
-               if s.ABI == obj.ABI0 && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABIInternal {
+               if objabi.Regabi_enabled == 1 && s.ABI == obj.ABI0 && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABIInternal {
                        // zeroing X15 when entering ABIInternal from ABI0
                        opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
                        // set G register from TLS
                        getgFromTLS(s, x86.REG_R14)
                }
                s.Call(v)
-               if s.ABI == obj.ABIInternal && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABI0 {
+               if objabi.Regabi_enabled == 1 && s.ABI == obj.ABIInternal && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABI0 {
                        // zeroing X15 when entering ABIInternal from ABI0
                        opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
                        // set G register from TLS
@@ -1333,7 +1334,7 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
        case ssa.BlockRet:
                s.Prog(obj.ARET)
        case ssa.BlockRetJmp:
-               if s.ABI == obj.ABI0 && b.Aux.(*obj.LSym).ABI() == obj.ABIInternal {
+               if objabi.Regabi_enabled == 1 && s.ABI == obj.ABI0 && b.Aux.(*obj.LSym).ABI() == obj.ABIInternal {
                        // zeroing X15 when entering ABIInternal from ABI0
                        opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
                        // set G register from TLS

diff --git a/src/cmd/compile/internal/ssa/gen/AMD64.rules b/src/cmd/compile/internal/ssa/gen/AMD64.rules
index 3c75bcfa05f61f8974d60b5c7051685f72d7e0c6..acd2170ea7fa11b5de587e6b6c6448b586e43289 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/AMD64.rules
+++ b/src/cmd/compile/internal/ssa/gen/AMD64.rules
@@ -459,7 +459,7 @@
 (IsInBounds idx len) => (SETB (CMPQ idx len))
 (IsSliceInBounds idx len) => (SETBE (CMPQ idx len))
 (NilCheck ...) => (LoweredNilCheck ...)
-(GetG mem) && !base.Flag.ABIWrap => (LoweredGetG mem) // only lower in old ABI. in new ABI we have a G register.
+(GetG mem) && !(objabi.Regabi_enabled == 1 && base.Flag.ABIWrap) => (LoweredGetG mem) // only lower in old ABI. in new ABI we have a G register.
 (GetClosurePtr ...) => (LoweredGetClosurePtr ...)
 (GetCallerPC ...) => (LoweredGetCallerPC ...)
 (GetCallerSP ...) => (LoweredGetCallerSP ...)

diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
index 03498c719c0956094970f77ee88324ee5012630d..4074d37d35dfdcc76a6e5caf4898c57bc1449d20 100644 (file)
--- a/src/cmd/compile/internal/ssa/rewriteAMD64.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go
@@ -4,6 +4,7 @@
 package ssa
 
 import "math"
+import "cmd/internal/objabi"
 import "cmd/compile/internal/base"
 import "cmd/compile/internal/types"
 
@@ -30129,11 +30130,11 @@ func rewriteValueAMD64_OpFloor(v *Value) bool {
 func rewriteValueAMD64_OpGetG(v *Value) bool {
        v_0 := v.Args[0]
        // match: (GetG mem)
-       // cond: !base.Flag.ABIWrap
+       // cond: !(objabi.Regabi_enabled == 1 && base.Flag.ABIWrap)
        // result: (LoweredGetG mem)
        for {
                mem := v_0
-               if !(!base.Flag.ABIWrap) {
+               if !(!(objabi.Regabi_enabled == 1 && base.Flag.ABIWrap)) {
                        break
                }
                v.reset(OpAMD64LoweredGetG)