sys/cpu: use symbolic names for masks

Masks declarations are copied from internal/cpu. All the 1<<N masks
that have a corresponding named constant are swapped out.

Change-Id: I6cfb053179a16611f4404719d92c182464a67d7f
Reviewed-on: https://go-review.googlesource.com/c/sys/+/731321
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>

cpu/cpu_x86.go

diff --git a/cpu/cpu_x86.go b/cpu/cpu_x86.go
index a5b5b5d..4c16131 100644
--- a/cpu/cpu_x86.go
+++ b/cpu/cpu_x86.go
@@ -64,6 +64,55 @@
 
 func archInit() {
 
+	const (
+		// eax bits
+		cpuid_AVXVNNI = 1 << 4
+
+		// ecx bits
+		cpuid_SSE3            = 1 << 0
+		cpuid_PCLMULQDQ       = 1 << 1
+		cpuid_AVX512VBMI      = 1 << 1
+		cpuid_AVX512VBMI2     = 1 << 6
+		cpuid_SSSE3           = 1 << 9
+		cpuid_AVX512GFNI      = 1 << 8
+		cpuid_AVX512VAES      = 1 << 9
+		cpuid_AVX512VNNI      = 1 << 11
+		cpuid_AVX512BITALG    = 1 << 12
+		cpuid_FMA             = 1 << 12
+		cpuid_AVX512VPOPCNTDQ = 1 << 14
+		cpuid_SSE41           = 1 << 19
+		cpuid_SSE42           = 1 << 20
+		cpuid_POPCNT          = 1 << 23
+		cpuid_AES             = 1 << 25
+		cpuid_OSXSAVE         = 1 << 27
+		cpuid_AVX             = 1 << 28
+
+		// "Extended Feature Flag" bits returned in EBX for CPUID EAX=0x7 ECX=0x0
+		cpuid_BMI1     = 1 << 3
+		cpuid_AVX2     = 1 << 5
+		cpuid_BMI2     = 1 << 8
+		cpuid_ERMS     = 1 << 9
+		cpuid_AVX512F  = 1 << 16
+		cpuid_AVX512DQ = 1 << 17
+		cpuid_ADX      = 1 << 19
+		cpuid_AVX512CD = 1 << 28
+		cpuid_SHA      = 1 << 29
+		cpuid_AVX512BW = 1 << 30
+		cpuid_AVX512VL = 1 << 31
+
+		// "Extended Feature Flag" bits returned in ECX for CPUID EAX=0x7 ECX=0x0
+		cpuid_AVX512_VBMI      = 1 << 1
+		cpuid_AVX512_VBMI2     = 1 << 6
+		cpuid_GFNI             = 1 << 8
+		cpuid_AVX512VPCLMULQDQ = 1 << 10
+		cpuid_AVX512_BITALG    = 1 << 12
+
+		// edx bits
+		cpuid_FSRM = 1 << 4
+		// edx bits for CPUID 0x80000001
+		cpuid_RDTSCP = 1 << 27
+	)
+
 	Initialized = true
 
 	maxID, _, _, _ := cpuid(0, 0)
@@ -75,16 +124,16 @@
 	_, _, ecx1, edx1 := cpuid(1, 0)
 	X86.HasSSE2 = isSet(edx1, 1<<26)
 
-	X86.HasSSE3 = isSet(ecx1, 1<<0)
-	X86.HasPCLMULQDQ = isSet(ecx1, 1<<1)
-	X86.HasSSSE3 = isSet(ecx1, 1<<9)
-	X86.HasFMA = isSet(ecx1, 1<<12)
+	X86.HasSSE3 = isSet(ecx1, cpuid_SSE3)
+	X86.HasPCLMULQDQ = isSet(ecx1, cpuid_PCLMULQDQ)
+	X86.HasSSSE3 = isSet(ecx1, cpuid_SSSE3)
+	X86.HasFMA = isSet(ecx1, cpuid_FMA)
 	X86.HasCX16 = isSet(ecx1, 1<<13)
-	X86.HasSSE41 = isSet(ecx1, 1<<19)
-	X86.HasSSE42 = isSet(ecx1, 1<<20)
-	X86.HasPOPCNT = isSet(ecx1, 1<<23)
-	X86.HasAES = isSet(ecx1, 1<<25)
-	X86.HasOSXSAVE = isSet(ecx1, 1<<27)
+	X86.HasSSE41 = isSet(ecx1, cpuid_SSE41)
+	X86.HasSSE42 = isSet(ecx1, cpuid_SSE42)
+	X86.HasPOPCNT = isSet(ecx1, cpuid_POPCNT)
+	X86.HasAES = isSet(ecx1, cpuid_AES)
+	X86.HasOSXSAVE = isSet(ecx1, cpuid_OSXSAVE)
 	X86.HasRDRAND = isSet(ecx1, 1<<30)
 
 	var osSupportsAVX, osSupportsAVX512 bool
@@ -103,40 +152,40 @@
 		}
 	}
 
-	X86.HasAVX = isSet(ecx1, 1<<28) && osSupportsAVX
+	X86.HasAVX = isSet(ecx1, cpuid_AVX) && osSupportsAVX
 
 	if maxID < 7 {
 		return
 	}
 
 	eax7, ebx7, ecx7, edx7 := cpuid(7, 0)
-	X86.HasBMI1 = isSet(ebx7, 1<<3)
-	X86.HasAVX2 = isSet(ebx7, 1<<5) && osSupportsAVX
-	X86.HasBMI2 = isSet(ebx7, 1<<8)
-	X86.HasERMS = isSet(ebx7, 1<<9)
+	X86.HasBMI1 = isSet(ebx7, cpuid_BMI1)
+	X86.HasAVX2 = isSet(ebx7, cpuid_AVX2) && osSupportsAVX
+	X86.HasBMI2 = isSet(ebx7, cpuid_BMI2)
+	X86.HasERMS = isSet(ebx7, cpuid_ERMS)
 	X86.HasRDSEED = isSet(ebx7, 1<<18)
-	X86.HasADX = isSet(ebx7, 1<<19)
+	X86.HasADX = isSet(ebx7, cpuid_ADX)
 
-	X86.HasAVX512 = isSet(ebx7, 1<<16) && osSupportsAVX512 // Because avx-512 foundation is the core required extension
+	X86.HasAVX512 = isSet(ebx7, cpuid_AVX512F) && osSupportsAVX512 // Because avx-512 foundation is the core required extension
 	if X86.HasAVX512 {
 		X86.HasAVX512F = true
-		X86.HasAVX512CD = isSet(ebx7, 1<<28)
+		X86.HasAVX512CD = isSet(ebx7, cpuid_AVX512CD)
 		X86.HasAVX512ER = isSet(ebx7, 1<<27)
 		X86.HasAVX512PF = isSet(ebx7, 1<<26)
-		X86.HasAVX512VL = isSet(ebx7, 1<<31)
-		X86.HasAVX512BW = isSet(ebx7, 1<<30)
-		X86.HasAVX512DQ = isSet(ebx7, 1<<17)
+		X86.HasAVX512VL = isSet(ebx7, cpuid_AVX512VL)
+		X86.HasAVX512BW = isSet(ebx7, cpuid_AVX512BW)
+		X86.HasAVX512DQ = isSet(ebx7, cpuid_AVX512DQ)
 		X86.HasAVX512IFMA = isSet(ebx7, 1<<21)
-		X86.HasAVX512VBMI = isSet(ecx7, 1<<1)
+		X86.HasAVX512VBMI = isSet(ecx7, cpuid_AVX512_VBMI)
 		X86.HasAVX5124VNNIW = isSet(edx7, 1<<2)
 		X86.HasAVX5124FMAPS = isSet(edx7, 1<<3)
-		X86.HasAVX512VPOPCNTDQ = isSet(ecx7, 1<<14)
-		X86.HasAVX512VPCLMULQDQ = isSet(ecx7, 1<<10)
-		X86.HasAVX512VNNI = isSet(ecx7, 1<<11)
-		X86.HasAVX512GFNI = isSet(ecx7, 1<<8)
-		X86.HasAVX512VAES = isSet(ecx7, 1<<9)
-		X86.HasAVX512VBMI2 = isSet(ecx7, 1<<6)
-		X86.HasAVX512BITALG = isSet(ecx7, 1<<12)
+		X86.HasAVX512VPOPCNTDQ = isSet(ecx7, cpuid_AVX512VPOPCNTDQ)
+		X86.HasAVX512VPCLMULQDQ = isSet(ecx7, cpuid_AVX512VPCLMULQDQ)
+		X86.HasAVX512VNNI = isSet(ecx7, cpuid_AVX512VNNI)
+		X86.HasAVX512GFNI = isSet(ecx7, cpuid_AVX512GFNI)
+		X86.HasAVX512VAES = isSet(ecx7, cpuid_AVX512VAES)
+		X86.HasAVX512VBMI2 = isSet(ecx7, cpuid_AVX512VBMI2)
+		X86.HasAVX512BITALG = isSet(ecx7, cpuid_AVX512BITALG)
 	}
 
 	X86.HasAMXTile = isSet(edx7, 1<<24)
@@ -151,7 +200,7 @@
 		}
 		if X86.HasAVX {
 			X86.HasAVXIFMA = isSet(eax71, 1<<23)
-			X86.HasAVXVNNI = isSet(eax71, 1<<4)
+			X86.HasAVXVNNI = isSet(eax71, cpuid_AVXVNNI)
 			X86.HasAVXVNNIInt8 = isSet(edx71, 1<<4)
 		}
 	}