From a029c75470284d76badcea91aee3d87f22042304 Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@users.sourceforge.net>
Date: Tue, 3 May 2011 19:02:52 +0200
Subject: [PATCH] Does not clobber ebx to allow compilation in PIC mode.

---
 cpu.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/cpu.h b/cpu.h
index d4426948..0609418a 100644
--- a/cpu.h
+++ b/cpu.h
@@ -31,9 +31,19 @@ static inline int cpu_has(uint32_t flag)
 	uint32_t eax = (flag >> 5) ? 0x80000001 : 1;
 	uint32_t edx;
 
-	asm volatile("cpuid"
+	asm volatile(
+#if defined(__i386__)
+		/* allow compilation in PIC mode saving ebx */
+		"push %%ebx\n"
+		"cpuid\n"
+		"pop %%ebx\n"
+		: "+a" (eax), "=d" (edx)
+		: : "ecx");
+#else
+		"cpuid\n"
 		: "+a" (eax), "=d" (edx)
 		: : "ecx", "ebx");
+#endif
 
 	return (edx >> (flag & 31)) & 1;
 }