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[PATCH 3/8 v4] net: Change x86_64 add32_with_carry to allow memory operand

From: Tom Herbert <hidden>
Date: 2014-05-02 23:28:41
Subsystem: the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

From Eric Dumazet:
Note add32_with_carry(a, b) is suboptimal, as it forces
a and b in registers.

b could be a memory or a register operand.

Signed-off-by: Tom Herbert <redacted>
---
 arch/x86/include/asm/checksum_64.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/checksum_64.h b/arch/x86/include/asm/checksum_64.h
index 3581761..cd00e17 100644
--- a/arch/x86/include/asm/checksum_64.h
+++ b/arch/x86/include/asm/checksum_64.h
@@ -184,7 +184,7 @@ static inline unsigned add32_with_carry(unsigned a, unsigned b)
 	asm("addl %2,%0\n\t"
 	    "adcl $0,%0"
 	    : "=r" (a)
-	    : "0" (a), "r" (b));
+	    : "0" (a), "rm" (b));
 	return a;
 }
 
-- 
1.9.1.423.g4596e3a
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