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[Qemu-devel] [PATCH v2] tcg-target.inc.c: Use byte form of xgetbv instru
From: |
John Arbuckle |
Subject: |
[Qemu-devel] [PATCH v2] tcg-target.inc.c: Use byte form of xgetbv instruction |
Date: |
Mon, 4 Jun 2018 17:51:02 -0400 |
Signed-off-by: John Arbuckle <address@hidden>
---
v2 changes:
- Fixed a spacing issue in the asm() function.
tcg/i386/tcg-target.inc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c
index 5357909fff..09141fa8e0 100644
--- a/tcg/i386/tcg-target.inc.c
+++ b/tcg/i386/tcg-target.inc.c
@@ -3501,7 +3501,11 @@ static void tcg_target_init(TCGContext *s)
sure of not hitting invalid opcode. */
if (c & bit_OSXSAVE) {
unsigned xcrl, xcrh;
- asm ("xgetbv" : "=a" (xcrl), "=d" (xcrh) : "c" (0));
+ /*
+ * The xgetbv instruction is not available to older versions of the
+ * assembler, so we encode the instruction manually.
+ */
+ asm(".byte 0x0f, 0x01, 0xd0" : "=a" (xcrl), "=d" (xcrh) : "c" (0));
if ((xcrl & 6) == 6) {
have_avx1 = (c & bit_AVX) != 0;
have_avx2 = (b7 & bit_AVX2) != 0;
--
2.14.3 (Apple Git-98)
- [Qemu-devel] [PATCH v2] tcg-target.inc.c: Use byte form of xgetbv instruction,
John Arbuckle <=