cmd/compile: don't emit unnecessary amd64 extension checks

In case of amd64 the compiler issues checks if extensions are available on a platform. With GOAMD64 microarchitecture levels provided, some of the checks could be eliminated. Change-Id: If15c178bcae273b2ce7d3673415cb8849292e087 Reviewed-on: https://go-review.googlesource.com/c/go/+/352010 Reviewed-by: Keith Randall <[email protected]> Reviewed-by: Matthew Dempsky <[email protected]> Run-TryBot: Keith Randall <[email protected]> TryBot-Result: Go Bot <[email protected]>
cloudflare · Oct 5, 2021 · 097a82f · 097a82f
1 parent 5d946f1
commit 097a82f
Show file tree

Hide file tree

Showing 3 changed files with 27 additions and 1 deletion.
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
@@ -4245,6 +4245,11 @@ func InitTables() {
  s.vars[n] = s.callResult(n, callNormal) // types.Types[TFLOAT64]
  return s.variable(n, types.Types[types.TFLOAT64])
  }
+
+ if buildcfg.GOAMD64 >= 3 {
+ return s.newValue3(ssa.OpFMA, types.Types[types.TFLOAT64], args[0], args[1], args[2])
+ }
+
  v := s.entryNewValue0A(ssa.OpHasCPUFeature, types.Types[types.TBOOL], ir.Syms.X86HasFMA)
  b := s.endBlock()
  b.Kind = ssa.BlockIf
@@ -4307,6 +4312,10 @@ func InitTables() {
 
  makeRoundAMD64 := func(op ssa.Op) func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
  return func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
+ if buildcfg.GOAMD64 >= 2 {
+ return s.newValue1(op, types.Types[types.TFLOAT64], args[0])
+ }
+
  v := s.entryNewValue0A(ssa.OpHasCPUFeature, types.Types[types.TBOOL], ir.Syms.X86HasSSE41)
  b := s.endBlock()
  b.Kind = ssa.BlockIf
@@ -4513,6 +4522,10 @@ func InitTables() {
 
  makeOnesCountAMD64 := func(op ssa.Op) func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
  return func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
+ if buildcfg.GOAMD64 >= 2 {
+ return s.newValue1(op, types.Types[types.TINT], args[0])
+ }
+
  v := s.entryNewValue0A(ssa.OpHasCPUFeature, types.Types[types.TBOOL], ir.Syms.X86HasPOPCNT)
  b := s.endBlock()
  b.Kind = ssa.BlockIf

diff --git a/test/codegen/math.go b/test/codegen/math.go
@@ -11,13 +11,17 @@ import "math"
 var sink64 [8]float64
 
 func approx(x float64) {
+ // amd64/v2:-".*x86HasSSE41" amd64/v3:-".*x86HasSSE41"
+ // amd64:"ROUNDSD\t[$]2"
  // s390x:"FIDBR\t[$]6"
  // arm64:"FRINTPD"
  // ppc64:"FRIP"
  // ppc64le:"FRIP"
  // wasm:"F64Ceil"
  sink64[0] = math.Ceil(x)
 
+ // amd64/v2:-".*x86HasSSE41" amd64/v3:-".*x86HasSSE41"
+ // amd64:"ROUNDSD\t[$]1"
  // s390x:"FIDBR\t[$]7"
  // arm64:"FRINTMD"
  // ppc64:"FRIM"
@@ -31,13 +35,17 @@ func approx(x float64) {
  // ppc64le:"FRIN"
  sink64[2] = math.Round(x)
 
+ // amd64/v2:-".*x86HasSSE41" amd64/v3:-".*x86HasSSE41"
+ // amd64:"ROUNDSD\t[$]3"
  // s390x:"FIDBR\t[$]5"
  // arm64:"FRINTZD"
  // ppc64:"FRIZ"
  // ppc64le:"FRIZ"
  // wasm:"F64Trunc"
  sink64[3] = math.Trunc(x)
 
+ // amd64/v2:-".*x86HasSSE41" amd64/v3:-".*x86HasSSE41"
+ // amd64:"ROUNDSD\t[$]0"
  // s390x:"FIDBR\t[$]4"
  // arm64:"FRINTND"
  // wasm:"F64Nearest"
@@ -123,6 +131,7 @@ func copysign(a, b, c float64) {
 }
 
 func fma(x, y, z float64) float64 {
+ // amd64/v3:-".*x86HasFMA"
  // amd64:"VFMADD231SD"
  // arm/6:"FMULAD"
  // arm64:"FMADDD"

diff --git a/test/codegen/mathbits.go b/test/codegen/mathbits.go
@@ -118,8 +118,9 @@ func Len8(n uint8) int {
 // bits.OnesCount //
 // -------------------- //
 
-// TODO(register args) Restore a m d 6 4 :.*x86HasPOPCNT when only one ABI is tested.
+// TODO(register args) Restore a m d 6 4 / v 1 :.*x86HasPOPCNT when only one ABI is tested.
 func OnesCount(n uint) int {
+ // amd64/v2:-".*x86HasPOPCNT" amd64/v3:-".*x86HasPOPCNT"
  // amd64:"POPCNTQ"
  // arm64:"VCNT","VUADDLV"
  // s390x:"POPCNT"
@@ -130,6 +131,7 @@ func OnesCount(n uint) int {
 }
 
 func OnesCount64(n uint64) int {
+ // amd64/v2:-".*x86HasPOPCNT" amd64/v3:-".*x86HasPOPCNT"
  // amd64:"POPCNTQ"
  // arm64:"VCNT","VUADDLV"
  // s390x:"POPCNT"
@@ -140,6 +142,7 @@ func OnesCount64(n uint64) int {
 }
 
 func OnesCount32(n uint32) int {
+ // amd64/v2:-".*x86HasPOPCNT" amd64/v3:-".*x86HasPOPCNT"
  // amd64:"POPCNTL"
  // arm64:"VCNT","VUADDLV"
  // s390x:"POPCNT"
@@ -150,6 +153,7 @@ func OnesCount32(n uint32) int {
 }
 
 func OnesCount16(n uint16) int {
+ // amd64/v2:-".*x86HasPOPCNT" amd64/v3:-".*x86HasPOPCNT"
  // amd64:"POPCNTL"
  // arm64:"VCNT","VUADDLV"
  // s390x:"POPCNT"