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tcg/i386: Use byte form of xgetbv instruction

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The assembler in most versions of Mac OS X is pretty old and does not
support the xgetbv instruction.  To go around this problem, the raw
encoding of the instruction is used instead.

Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-Id: <20180604215102.11002-1-programmingkidx@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
John Arbuckle 2018-06-04 17:51:02 -04:00 committed by Richard Henderson
parent 42747d6abb
commit 1019242af1
1 changed files with 4 additions and 1 deletions
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5
tcg/i386/tcg-target.inc.c
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@ -3501,7 +3501,10 @@ 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;