poly1305: fix bug in amd64 assembly

Add the conditional subtraction of 3 from 'h2' (register R10). Change-Id: I75615b0375f050a5cd97b968075c2992ccd1dee7 Reviewed-on: https://go-review.googlesource.com/30101 Reviewed-by: Adam Langley <agl@golang.org>
LewiGoddard · Oct 2, 2016 · 380809d · 380809d
1 parent 7fb8d38
commit 380809d
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/poly1305/poly1305_amd64.s b/poly1305/poly1305_amd64.s
@@ -121,6 +121,7 @@ done:
 	MOVQ    R9, BX
 	SUBQ    $0xFFFFFFFFFFFFFFFB, AX
 	SBBQ    $0xFFFFFFFFFFFFFFFF, BX
+	SBBQ    $3, R10
 	CMOVQCS R8, AX
 	CMOVQCS R9, BX
 	ADDQ    16(SP), AX