From: Eric Biggers <ebiggers3@gmail.com>
Date: Sat, 22 Aug 2015 16:47:15 +0000 (-0500)
Subject: x86_cpu_features.c: xgetbv fix for old binutils
X-Git-Tag: v1.8.2~2
X-Git-Url: https://wimlib.net/git/?p=wimlib;a=commitdiff_plain;h=56c8b5eaacef8a5563261b9034a8a011480bba6e;hp=719a063c87e3abab99b0fb53ebc80223fbf33123;ds=sidebyside

x86_cpu_features.c: xgetbv fix for old binutils
---

diff --git a/src/x86_cpu_features.c b/src/x86_cpu_features.c
index aab200ff..5e434f9f 100644
--- a/src/x86_cpu_features.c
+++ b/src/x86_cpu_features.c
@@ -47,7 +47,9 @@ read_xcr(u32 index)
 {
 	u32 edx, eax;
 
-	__asm__ ("xgetbv" : "=d" (edx), "=a" (eax) : "c" (index));
+	/* Execute the "xgetbv" instruction.  Old versions of binutils do not
+	 * recognize this instruction, so list the raw bytes instead.  */
+	__asm__ (".byte 0x0f, 0x01, 0xd0" : "=d" (edx), "=a" (eax) : "c" (index));
 
 	return ((u64)edx << 32) | eax;
 }