X86: Fix carry calculation for subtraction based microops.

The carry flag should be calculated using the -complement- of the second operand, not it's negation. The carry in which is part of computing the 2's complement may induce a carry, but if you've already caused the carry before you get the carry computing logic involved, it will miss it.

--HG--
extra : convert_revision : 318cf86929664fc52ed9e023606a9e892eba635c

diff --git a/src/arch/x86/isa/microops/regop.isa b/src/arch/x86/isa/microops/regop.isa
index c3f0089937848578c78790dddbde6e917f90f0b8..bb34df7dfffb0fbdc60635955b5f018ecc36c287 100644 (file)
--- a/src/arch/x86/isa/microops/regop.isa
+++ b/src/arch/x86/isa/microops/regop.isa
@@ -343,7 +343,7 @@ let {{
         immCode = matcher.sub("imm8", code)
 
         if subtract:
-            secondSrc = "-op2, true"
+            secondSrc = "~op2, true"
         else:
             secondSrc = "op2"