runtime: make processor capability variable naming platform specific

The current support_XXX variables are specific for the
amd64 and 386 platforms.

Prefix processor capability variables by architecture to have a
consistent naming scheme and avoid reuse of the existing
variables for new platforms.

This also aligns naming of runtime variables closer with internal/cpu
processor capability variable names.

Change-Id: I3eabb29a03874678851376185d3a62e73c1aff1d
Reviewed-on: https://go-review.googlesource.com/c/91435
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/gc/builtin.go

@@ -144,8 +144,9 @@ var runtimeDecls = [...]struct {
 	{"racewriterange", funcTag, 113},
 	{"msanread", funcTag, 113},
 	{"msanwrite", funcTag, 113},
-	{"support_popcnt", varTag, 11},
-	{"support_sse41", varTag, 11},
+	{"x86HasPOPCNT", varTag, 11},
+	{"x86HasSSE41", varTag, 11},
+	{"arm64HasATOMICS", varTag, 11},
 }
 
 func runtimeTypes() []*types.Type {

src/cmd/compile/internal/gc/builtin/runtime.go

@@ -195,5 +195,6 @@ func msanread(addr, size uintptr)
 func msanwrite(addr, size uintptr)
 
 // architecture variants
-var support_popcnt bool
-var support_sse41 bool
+var x86HasPOPCNT bool
+var x86HasSSE41 bool
+var arm64HasATOMICS bool

src/cmd/compile/internal/gc/go.go

@@ -305,9 +305,9 @@ var (
 	racereadrange,
 	racewrite,
 	racewriterange,
-	supportPopcnt,
-	supportSSE41,
-	arm64SupportAtomics,
+	x86HasPOPCNT,
+	x86HasSSE41,
+	arm64HasATOMICS,
 	typedmemclr,
 	typedmemmove,
 	Udiv,

src/cmd/compile/internal/gc/ssa.go

@@ -86,9 +86,9 @@ func initssaconfig() {
 	racereadrange = sysfunc("racereadrange")
 	racewrite = sysfunc("racewrite")
 	racewriterange = sysfunc("racewriterange")
-	supportPopcnt = sysvar("support_popcnt")              // bool
-	supportSSE41 = sysvar("support_sse41")                // bool
-	arm64SupportAtomics = sysvar("arm64_support_atomics") // bool
+	x86HasPOPCNT = sysvar("x86HasPOPCNT")       // bool
+	x86HasSSE41 = sysvar("x86HasSSE41")         // bool
+	arm64HasATOMICS = sysvar("arm64HasATOMICS") // bool
 	typedmemclr = sysfunc("typedmemclr")
 	typedmemmove = sysfunc("typedmemmove")
 	Udiv = sysvar("udiv")                 // asm func with special ABI
@@ -3068,7 +3068,7 @@ func init() {
 	makeXaddARM64 := func(op0 ssa.Op, op1 ssa.Op, ty types.EType) func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 		return func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 			// Target Atomic feature is identified by dynamic detection
-			addr := s.entryNewValue1A(ssa.OpAddr, types.Types[TBOOL].PtrTo(), arm64SupportAtomics, s.sb)
+			addr := s.entryNewValue1A(ssa.OpAddr, types.Types[TBOOL].PtrTo(), arm64HasATOMICS, s.sb)
 			v := s.load(types.Types[TBOOL], addr)
 			b := s.endBlock()
 			b.Kind = ssa.BlockIf
@@ -3208,7 +3208,7 @@ func init() {
 
 	makeRoundAMD64 := func(op ssa.Op) func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 		return func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
-			addr := s.entryNewValue1A(ssa.OpAddr, types.Types[TBOOL].PtrTo(), supportSSE41, s.sb)
+			addr := s.entryNewValue1A(ssa.OpAddr, types.Types[TBOOL].PtrTo(), x86HasSSE41, s.sb)
 			v := s.load(types.Types[TBOOL], addr)
 			b := s.endBlock()
 			b.Kind = ssa.BlockIf
@@ -3416,7 +3416,7 @@ func init() {
 
 	makeOnesCountAMD64 := func(op64 ssa.Op, op32 ssa.Op) func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 		return func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
-			addr := s.entryNewValue1A(ssa.OpAddr, types.Types[TBOOL].PtrTo(), supportPopcnt, s.sb)
+			addr := s.entryNewValue1A(ssa.OpAddr, types.Types[TBOOL].PtrTo(), x86HasPOPCNT, s.sb)
 			v := s.load(types.Types[TBOOL], addr)
 			b := s.endBlock()
 			b.Kind = ssa.BlockIf

src/cmd/compile/internal/ssa/gen/AMD64Ops.go

@@ -467,14 +467,14 @@ func init() {
 		{name: "BSWAPL", argLength: 1, reg: gp11, asm: "BSWAPL", resultInArg0: true, clobberFlags: true}, // arg0 swap bytes
 
 		// POPCNT instructions aren't guaranteed to be on the target platform (they are SSE4).
-		// Any use must be preceded by a successful check of runtime.support_popcnt.
+		// Any use must be preceded by a successful check of runtime.x86HasPOPCNT.
 		{name: "POPCNTQ", argLength: 1, reg: gp11, asm: "POPCNTQ", clobberFlags: true}, // count number of set bits in arg0
 		{name: "POPCNTL", argLength: 1, reg: gp11, asm: "POPCNTL", clobberFlags: true}, // count number of set bits in arg0
 
 		{name: "SQRTSD", argLength: 1, reg: fp11, asm: "SQRTSD"}, // sqrt(arg0)
 
 		// ROUNDSD instruction isn't guaranteed to be on the target platform (it is SSE4.1)
-		// Any use must be preceded by a successful check of runtime.support_sse41.
+		// Any use must be preceded by a successful check of runtime.x86HasSSE41.
 		{name: "ROUNDSD", argLength: 1, reg: fp11, aux: "Int8", asm: "ROUNDSD"}, // rounds arg0 depending on auxint, 1 means math.Floor, 2 Ceil, 3 Trunc
 
 		{name: "SBBQcarrymask", argLength: 1, reg: flagsgp, asm: "SBBQ"}, // (int64)(-1) if carry is set, 0 if carry is clear.

src/runtime/cpuflags.go

@@ -17,3 +17,12 @@ const (
 
 	offsetARMHasIDIVA = unsafe.Offsetof(cpu.ARM.HasIDIVA)
 )
+
+var (
+	// Set in runtime.cpuinit.
+	// TODO: deprecate these; use internal/cpu directly.
+	x86HasPOPCNT bool
+	x86HasSSE41  bool
+
+	arm64HasATOMICS bool
+)

src/runtime/proc.go

@@ -509,10 +509,10 @@ func cpuinit() {
 
 	// Support cpu feature variables are used in code generated by the compiler
 	// to guard execution of instructions that can not be assumed to be always supported.
-	support_popcnt = cpu.X86.HasPOPCNT
-	support_sse41 = cpu.X86.HasSSE41
+	x86HasPOPCNT = cpu.X86.HasPOPCNT
+	x86HasSSE41 = cpu.X86.HasSSE41
 
-	arm64_support_atomics = cpu.ARM64.HasATOMICS
+	arm64HasATOMICS = cpu.ARM64.HasATOMICS
 }
 
 // The bootstrap sequence is:

src/runtime/runtime2.go

@@ -858,12 +858,6 @@ var (
 	isIntel              bool
 	lfenceBeforeRdtsc    bool
 
-	// Set in runtime.cpuinit.
-	// TODO: deprecate these; use internal/cpu directly.
-	support_popcnt        bool
-	support_sse41         bool
-	arm64_support_atomics bool
-
 	goarm                uint8 // set by cmd/link on arm systems
 	framepointer_enabled bool  // set by cmd/link
 )

test/codegen/mathbits.go

@@ -101,7 +101,7 @@ func Len8(n uint8) int {
 // -------------------- //
 
 func OnesCount(n uint) int {
-	// amd64:"POPCNTQ",".*support_popcnt"
+	// amd64:"POPCNTQ",".*x86HasPOPCNT"
 	// arm64:"VCNT","VUADDLV"
 	// s390x:"POPCNT"
 	// ppc64:"POPCNTD"
@@ -110,7 +110,7 @@ func OnesCount(n uint) int {
 }
 
 func OnesCount64(n uint64) int {
-	// amd64:"POPCNTQ",".*support_popcnt"
+	// amd64:"POPCNTQ",".*x86HasPOPCNT"
 	// arm64:"VCNT","VUADDLV"
 	// s390x:"POPCNT"
 	// ppc64:"POPCNTD"
@@ -119,7 +119,7 @@ func OnesCount64(n uint64) int {
 }
 
 func OnesCount32(n uint32) int {
-	// amd64:"POPCNTL",".*support_popcnt"
+	// amd64:"POPCNTL",".*x86HasPOPCNT"
 	// arm64:"VCNT","VUADDLV"
 	// s390x:"POPCNT"
 	// ppc64:"POPCNTW"
@@ -128,7 +128,7 @@ func OnesCount32(n uint32) int {
 }
 
 func OnesCount16(n uint16) int {
-	// amd64:"POPCNTL",".*support_popcnt"
+	// amd64:"POPCNTL",".*x86HasPOPCNT"
 	// arm64:"VCNT","VUADDLV"
 	// s390x:"POPCNT"
 	// ppc64:"POPCNTW"