cmd/compile, runtime: remove plan9 special case avoiding SSE

Change-Id: Id5258a72b0727bf7c66d558e30486eac2c6c8c36
Reviewed-on: https://go-review.googlesource.com/c/go/+/655875
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: David du Colombier <0intro@gmail.com>

diff --git a/src/cmd/compile/internal/amd64/ggen.go b/src/cmd/compile/internal/amd64/ggen.go
index db98a22a1e1927a237aa40f4a3b4311c86ca05f4..1dc952a4557c12dd13dfb4787121ae3b32543cc3 100644 (file)
--- a/src/cmd/compile/internal/amd64/ggen.go
+++ b/src/cmd/compile/internal/amd64/ggen.go
@@ -10,12 +10,8 @@ import (
        "cmd/compile/internal/types"
        "cmd/internal/obj"
        "cmd/internal/obj/x86"
-       "internal/buildcfg"
 )
 
-// no floating point in note handlers on Plan 9
-var isPlan9 = buildcfg.GOOS == "plan9"
-
 // DUFFZERO consists of repeated blocks of 4 MOVUPSs + LEAQ,
 // See runtime/mkduff.go.
 const (
@@ -64,7 +60,7 @@ func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, state *uint32) *obj.
 
        if cnt == 8 {
                p = pp.Append(p, x86.AMOVQ, obj.TYPE_REG, x86.REG_X15, 0, obj.TYPE_MEM, x86.REG_SP, off)
-       } else if !isPlan9 && cnt <= int64(8*types.RegSize) {
+       } else if cnt <= int64(8*types.RegSize) {
                for i := int64(0); i < cnt/16; i++ {
                        p = pp.Append(p, x86.AMOVUPS, obj.TYPE_REG, x86.REG_X15, 0, obj.TYPE_MEM, x86.REG_SP, off+i*16)
                }
@@ -72,7 +68,7 @@ func zerorange(pp *objw.Progs, p *obj.Prog, off, cnt int64, state *uint32) *obj.
                if cnt%16 != 0 {
                        p = pp.Append(p, x86.AMOVUPS, obj.TYPE_REG, x86.REG_X15, 0, obj.TYPE_MEM, x86.REG_SP, off+cnt-int64(16))
                }
-       } else if !isPlan9 && (cnt <= int64(128*types.RegSize)) {
+       } else if cnt <= int64(128*types.RegSize) {
                // Save DI to r12. With the amd64 Go register abi, DI can contain
                // an incoming parameter, whereas R12 is always scratch.
                p = pp.Append(p, x86.AMOVQ, obj.TYPE_REG, x86.REG_DI, 0, obj.TYPE_REG, x86.REG_R12, 0)

diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index 332c49af0012ac5d604adb93e3784ab540c1e58b..c97cdbd5c049de0dfce178d7dcfa0343b833d4af 100644 (file)
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -6,7 +6,6 @@ package amd64
 
 import (
        "fmt"
-       "internal/buildcfg"
        "math"
 
        "cmd/compile/internal/base"
@@ -1090,9 +1089,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
        case ssa.OpAMD64CALLstatic, ssa.OpAMD64CALLtail:
                if s.ABI == obj.ABI0 && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABIInternal {
                        // zeroing X15 when entering ABIInternal from ABI0
-                       if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
-                               opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
-                       }
+                       opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
                        // set G register from TLS
                        getgFromTLS(s, x86.REG_R14)
                }
@@ -1103,9 +1100,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
                s.Call(v)
                if s.ABI == obj.ABIInternal && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABI0 {
                        // zeroing X15 when entering ABIInternal from ABI0
-                       if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
-                               opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
-                       }
+                       opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
                        // set G register from TLS
                        getgFromTLS(s, x86.REG_R14)
                }

diff --git a/src/cmd/compile/internal/ssa/config.go b/src/cmd/compile/internal/ssa/config.go
index ed3795285eb87e7ec0b1766581b6d6866cf5966f..167da842ff81a5bb198e96705e76c55ca4a2391f 100644 (file)
--- a/src/cmd/compile/internal/ssa/config.go
+++ b/src/cmd/compile/internal/ssa/config.go
@@ -369,12 +369,6 @@ func NewConfig(arch string, types Types, ctxt *obj.Link, optimize, softfloat boo
        if buildcfg.GOOS == "plan9" {
                // Don't use FMA on Plan 9
                c.UseFMA = false
-
-               // Don't use Duff's device and SSE on Plan 9 AMD64.
-               if arch == "amd64" {
-                       c.noDuffDevice = true
-                       c.useSSE = false
-               }
        }
 
        if ctxt.Flag_shared {

diff --git a/src/runtime/asm_amd64.s b/src/runtime/asm_amd64.s
index 2fa953f39f08403a6f81d1da7fac76828070005f..9c262a7ce8703640ccd52d27431048841015c54b 100644 (file)
--- a/src/runtime/asm_amd64.s
+++ b/src/runtime/asm_amd64.s
@@ -1710,9 +1710,7 @@ TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0
 TEXT ·sigpanic0(SB),NOSPLIT,$0-0
        get_tls(R14)
        MOVQ    g(R14), R14
-#ifndef GOOS_plan9
        XORPS   X15, X15
-#endif
        JMP     ·sigpanic<ABIInternal>(SB)
 
 // gcWriteBarrier informs the GC about heap pointer writes.