From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Fri, 5 Oct 2018 17:51:57 +0000 (+0000)
Subject: libgo: use inline assembly in favor of call to _xgetbv()
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7fc9c2e52f66a2b8aa101ef918829046f8f517e8;p=gcc.git

libgo: use inline assembly in favor of call to _xgetbv()

    Use inline assembly in the implementation of internal_cpu.xgetbv as
    opposed to a call to the intrinsic _xgetbv(), since non-gcc compilers
    (e.g. clang) may or may not have support for it.

    Reviewed-on: https://go-review.googlesource.com/c/140137

From-SVN: r264882
---

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index b28c8d333ef..2c7a860c8a8 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-9f4cf23e716bcf65e071260afa032a64acd3fdde
+d0739c13ca3686df1f8d0fae7c6c5caaed058503
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/libgo/go/internal/cpu/cpu_gccgo.c b/libgo/go/internal/cpu/cpu_gccgo.c
index 6625ddccabb..1d5b492a787 100644
--- a/libgo/go/internal/cpu/cpu_gccgo.c
+++ b/libgo/go/internal/cpu/cpu_gccgo.c
@@ -52,12 +52,18 @@ struct xgetbv_ret xgetbv(void)
 #pragma GCC target("xsave")
 
 struct xgetbv_ret xgetbv(void) {
-	long long r;
 	struct xgetbv_ret ret;
 
-	r = _xgetbv(0);
-	ret.eax = r & 0xffffffff;
-	ret.edx = r >> 32;
+        // At some point, use call to _xgetbv() instead:
+        //
+        //       long long r = _xgetbv(0);
+        //       ret.eax = r & 0xffffffff;
+        //       ret.edx = r >> 32;
+        //
+        unsigned int __eax, __edx, __xcr_no = 0;
+        __asm__ ("xgetbv" : "=a" (__eax), "=d" (__edx) : "c" (__xcr_no));
+        ret.eax = __eax;
+        ret.edx = __edx;
 	return ret;
 }