cpu: add gccgo implementation
It uses __get_cpuid_count, provided by cpuid.h.
The xgetbv is implemented after its counterpart in cpu_x86.s.
Change-Id: I97624d7da67ab4ec3c9a53b0bfc4dfcdf7d12c87
Reviewed-on: https://go-review.googlesource.com/116155
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/cpu/cpu_gccgo.c b/cpu/cpu_gccgo.c
new file mode 100644
index 0000000..e363c7d
--- /dev/null
+++ b/cpu/cpu_gccgo.c
@@ -0,0 +1,43 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build 386 amd64 amd64p32
+// +build gccgo
+
+#include <cpuid.h>
+#include <stdint.h>
+
+// Need to wrap __get_cpuid_count because it's declared as static.
+int
+gccgoGetCpuidCount(uint32_t leaf, uint32_t subleaf,
+ uint32_t *eax, uint32_t *ebx,
+ uint32_t *ecx, uint32_t *edx)
+{
+ return __get_cpuid_count(leaf, subleaf, eax, ebx, ecx, edx);
+}
+
+// xgetbv reads the contents of an XCR (Extended Control Register)
+// specified in the ECX register into registers EDX:EAX.
+// Currently, the only supported value for XCR is 0.
+//
+// TODO: Replace with a better alternative:
+//
+// #include <xsaveintrin.h>
+//
+// #pragma GCC target("xsave")
+//
+// void gccgoXgetbv(uint32_t *eax, uint32_t *edx) {
+// unsigned long long x = _xgetbv(0);
+// *eax = x & 0xffffffff;
+// *edx = (x >> 32) & 0xffffffff;
+// }
+//
+// Note that _xgetbv is defined starting with GCC 8.
+void
+gccgoXgetbv(uint32_t *eax, uint32_t *edx)
+{
+ __asm(" xorl %%ecx, %%ecx\n"
+ " xgetbv"
+ : "=a"(*eax), "=d"(*edx));
+}
diff --git a/cpu/cpu_gccgo.go b/cpu/cpu_gccgo.go
new file mode 100644
index 0000000..ba49b91
--- /dev/null
+++ b/cpu/cpu_gccgo.go
@@ -0,0 +1,26 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build 386 amd64 amd64p32
+// +build gccgo
+
+package cpu
+
+//extern gccgoGetCpuidCount
+func gccgoGetCpuidCount(eaxArg, ecxArg uint32, eax, ebx, ecx, edx *uint32)
+
+func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32) {
+ var a, b, c, d uint32
+ gccgoGetCpuidCount(eaxArg, ecxArg, &a, &b, &c, &d)
+ return a, b, c, d
+}
+
+//extern gccgoXgetbv
+func gccgoXgetbv(eax, edx *uint32)
+
+func xgetbv() (eax, edx uint32) {
+ var a, d uint32
+ gccgoXgetbv(&a, &d)
+ return a, d
+}
diff --git a/cpu/cpu_x86.go b/cpu/cpu_x86.go
index 8842b7c..ffc90d6 100644
--- a/cpu/cpu_x86.go
+++ b/cpu/cpu_x86.go
@@ -8,10 +8,12 @@
const cacheLineSize = 64
-// cpuid is implemented in cpu_x86.s.
+// cpuid is implemented in cpu_x86.s for gc compiler
+// and in cpu_gccgo.c for gccgo.
func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
-// xgetbv with ecx = 0 is implemented in cpu_x86.s.
+// 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)
func init() {
diff --git a/cpu/cpu_x86.s b/cpu/cpu_x86.s
index 4ff61e0..47f0841 100644
--- a/cpu/cpu_x86.s
+++ b/cpu/cpu_x86.s
@@ -3,6 +3,7 @@
// license that can be found in the LICENSE file.
// +build 386 amd64 amd64p32
+// +build !gccgo
#include "textflag.h"
