libgo: update to Go1.17rc2

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/341629

23 files changed, 46 insertions, 11 deletions

diff --git a/libgo/go/golang.org/x/sys/cpu/cpu.go b/libgo/go/golang.org/x/sys/cpu/cpu.go
index f77701f..abbec2d 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu.go
@@ -154,14 +154,13 @@ var MIPS64X struct {
 // For ppc64/ppc64le, it is safe to check only for ISA level starting on ISA v3.00,
 // since there are no optional categories. There are some exceptions that also
 // require kernel support to work (DARN, SCV), so there are feature bits for
-// those as well. The minimum processor requirement is POWER8 (ISA 2.07).
-// The struct is padded to avoid false sharing.
+// those as well. The struct is padded to avoid false sharing.
 var PPC64 struct {
 	_        CacheLinePad
 	HasDARN  bool // Hardware random number generator (requires kernel enablement)
 	HasSCV   bool // Syscall vectored (requires kernel enablement)
 	IsPOWER8 bool // ISA v2.07 (POWER8)
-	IsPOWER9 bool // ISA v3.00 (POWER9)
+	IsPOWER9 bool // ISA v3.00 (POWER9), implies IsPOWER8
 	_        CacheLinePad
 }
 
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_aix.go b/libgo/go/golang.org/x/sys/cpu/cpu_aix.go
index 464a209..8aaeef5 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_aix.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_aix.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build aix
 // +build aix
 
 package cpu
@@ -19,6 +20,7 @@ func archInit() {
 		PPC64.IsPOWER8 = true
 	}
 	if impl&_IMPL_POWER9 != 0 {
+		PPC64.IsPOWER8 = true
 		PPC64.IsPOWER9 = true
 	}
 
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_gc_arm64.go b/libgo/go/golang.org/x/sys/cpu/cpu_gc_arm64.go
index 7f7f272..ccf542a 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_gc_arm64.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_gc_arm64.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build gc
 // +build gc
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_gc_s390x.go b/libgo/go/golang.org/x/sys/cpu/cpu_gc_s390x.go
index 75a9556..0af2f24 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_gc_s390x.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_gc_s390x.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build gc
 // +build gc
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_gc_x86.go b/libgo/go/golang.org/x/sys/cpu/cpu_gc_x86.go
index 4adb89c..3298a87 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_gc_x86.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_gc_x86.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build (386 || amd64 || amd64p32) && gc
 // +build 386 amd64 amd64p32
 // +build gc
 
@@ -14,3 +15,7 @@ func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
 // xgetbv with ecx = 0 is implemented in cpu_x86.s for gc compiler
 // and in cpu_gccgo.c for gccgo.
 func xgetbv() (eax, edx uint32)
+
+// darwinSupportsAVX512 is implemented in cpu_x86.s for gc compiler
+// and in cpu_gccgo_x86.go for gccgo.
+func darwinSupportsAVX512() bool
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_arm64.go b/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_arm64.go
index 53ca8d6..2aff318 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_arm64.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_arm64.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build gccgo
 // +build gccgo
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_s390x.go b/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_s390x.go
index aa986f7..4bfbda6 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_s390x.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_s390x.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build gccgo
 // +build gccgo
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_x86.go b/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_x86.go
index ba49b91..863d415 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_x86.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_gccgo_x86.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build (386 || amd64 || amd64p32) && gccgo
 // +build 386 amd64 amd64p32
 // +build gccgo
 
@@ -24,3 +25,9 @@ func xgetbv() (eax, edx uint32) {
 	gccgoXgetbv(&a, &d)
 	return a, d
 }
+
+// gccgo doesn't build on Darwin, per:
+// https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/gcc.rb#L76
+func darwinSupportsAVX512() bool {
+	return false
+}
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_linux.go b/libgo/go/golang.org/x/sys/cpu/cpu_linux.go
index 6fc874f..159a686 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_linux.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_linux.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !386 && !amd64 && !amd64p32 && !arm64
 // +build !386,!amd64,!amd64p32,!arm64
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_linux_mips64x.go b/libgo/go/golang.org/x/sys/cpu/cpu_linux_mips64x.go
index 5a41890..6000db4 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_linux_mips64x.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_linux_mips64x.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && (mips64 || mips64le)
 // +build linux
 // +build mips64 mips64le
 
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_linux_noinit.go b/libgo/go/golang.org/x/sys/cpu/cpu_linux_noinit.go
index 42b5d33..f4992b1 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_linux_noinit.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_linux_noinit.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && !arm && !arm64 && !mips64 && !mips64le && !ppc64 && !ppc64le && !s390x
 // +build linux,!arm,!arm64,!mips64,!mips64le,!ppc64,!ppc64le,!s390x
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_linux_ppc64x.go b/libgo/go/golang.org/x/sys/cpu/cpu_linux_ppc64x.go
index 99f8a63..021356d 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_linux_ppc64x.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_linux_ppc64x.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build linux && (ppc64 || ppc64le)
 // +build linux
 // +build ppc64 ppc64le
 
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_mips64x.go b/libgo/go/golang.org/x/sys/cpu/cpu_mips64x.go
index eb4e010..d10b980 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_mips64x.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_mips64x.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips64 || mips64le
 // +build mips64 mips64le
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_mipsx.go b/libgo/go/golang.org/x/sys/cpu/cpu_mipsx.go
index f6767b7..e67e88f 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_mipsx.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_mipsx.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build mips || mipsle
 // +build mips mipsle
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_other_arm.go b/libgo/go/golang.org/x/sys/cpu/cpu_other_arm.go
index b412efc..d7b4fb4 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_other_arm.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_other_arm.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !linux && arm
 // +build !linux,arm
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_other_arm64.go b/libgo/go/golang.org/x/sys/cpu/cpu_other_arm64.go
index 16c1c40..f8c484f 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_other_arm64.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_other_arm64.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !linux,!netbsd
-// +build arm64
+//go:build !linux && !netbsd && arm64
+// +build !linux,!netbsd,arm64
 
 package cpu
 
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_other_mips64x.go b/libgo/go/golang.org/x/sys/cpu/cpu_other_mips64x.go
index f49fad6..0dafe96 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_other_mips64x.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_other_mips64x.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !linux && (mips64 || mips64le)
 // +build !linux
 // +build mips64 mips64le
 
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_ppc64x.go b/libgo/go/golang.org/x/sys/cpu/cpu_ppc64x.go
index aedfb17..f2e92c0 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_ppc64x.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_ppc64x.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build ppc64 || ppc64le
 // +build ppc64 ppc64le
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_riscv64.go b/libgo/go/golang.org/x/sys/cpu/cpu_riscv64.go
index 2001b99..edfa5b7 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_riscv64.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_riscv64.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build riscv64
 // +build riscv64
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_wasm.go b/libgo/go/golang.org/x/sys/cpu/cpu_wasm.go
index 60017a6..8d4e8fb 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_wasm.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_wasm.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build wasm
 // +build wasm
 
 package cpu
diff --git a/libgo/go/golang.org/x/sys/cpu/cpu_x86.go b/libgo/go/golang.org/x/sys/cpu/cpu_x86.go
index 8cc67e6..e50ed98 100644
--- a/libgo/go/golang.org/x/sys/cpu/cpu_x86.go
+++ b/libgo/go/golang.org/x/sys/cpu/cpu_x86.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build 386 || amd64 || amd64p32
 // +build 386 amd64 amd64p32
 
 package cpu
@@ -86,8 +87,14 @@ func archInit() {
 		// Check if XMM and YMM registers have OS support.
 		osSupportsAVX = isSet(1, eax) && isSet(2, eax)
 
-		// Check if OPMASK and ZMM registers have OS support.
-		osSupportsAVX512 = osSupportsAVX && isSet(5, eax) && isSet(6, eax) && isSet(7, eax)
+		if runtime.GOOS == "darwin" {
+			// Check darwin commpage for AVX512 support. Necessary because:
+			// https://github.com/apple/darwin-xnu/blob/0a798f6738bc1db01281fc08ae024145e84df927/osfmk/i386/fpu.c#L175-L201
+			osSupportsAVX512 = osSupportsAVX && darwinSupportsAVX512()
+		} else {
+			// Check if OPMASK and ZMM registers have OS support.
+			osSupportsAVX512 = osSupportsAVX && isSet(5, eax) && isSet(6, eax) && isSet(7, eax)
+		}
 	}
 
 	X86.HasAVX = isSet(28, ecx1) && osSupportsAVX
diff --git a/libgo/go/golang.org/x/sys/cpu/syscall_aix_gccgo.go b/libgo/go/golang.org/x/sys/cpu/syscall_aix_gccgo.go
index 76fbe40..a864f24 100644
--- a/libgo/go/golang.org/x/sys/cpu/syscall_aix_gccgo.go
+++ b/libgo/go/golang.org/x/sys/cpu/syscall_aix_gccgo.go
@@ -8,8 +8,8 @@
 // Morever, this file will be used during the building of
 // gccgo's libgo and thus must not used a CGo method.
 
-// +build aix
-// +build gccgo
+//go:build aix && gccgo
+// +build aix,gccgo
 
 package cpu
 
diff --git a/libgo/go/golang.org/x/sys/cpu/syscall_aix_ppc64_gc.go b/libgo/go/golang.org/x/sys/cpu/syscall_aix_ppc64_gc.go
index 5b427d6..904be42 100644
--- a/libgo/go/golang.org/x/sys/cpu/syscall_aix_ppc64_gc.go
+++ b/libgo/go/golang.org/x/sys/cpu/syscall_aix_ppc64_gc.go
@@ -6,8 +6,8 @@
 // system call on AIX without depending on x/sys/unix.
 // (See golang.org/issue/32102)
 
-// +build aix,ppc64
-// +build gc
+//go:build aix && ppc64 && gc
+// +build aix,ppc64,gc
 
 package cpu