From: Julian Seward <jseward@acm.org>
Date: Fri, 2 May 2008 22:15:12 +0000 (+0000)
Subject: Specialise CondNZ after SUBW for both x86 and amd64.
X-Git-Tag: svn/VALGRIND_3_4_1^2~34
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cb283b95c122caef83a4ab7f58b08123424a7791;p=thirdparty%2Fvalgrind.git

Specialise CondNZ after SUBW for both x86 and amd64.


git-svn-id: svn://svn.valgrind.org/vex/trunk@1833
---

diff --git a/VEX/priv/guest-amd64/ghelpers.c b/VEX/priv/guest-amd64/ghelpers.c
index 2f2bf7e047..d3140f9c4b 100644
--- a/VEX/priv/guest-amd64/ghelpers.c
+++ b/VEX/priv/guest-amd64/ghelpers.c
@@ -1001,6 +1001,13 @@ IRExpr* guest_amd64_spechelper ( HChar* function_name,
                            unop(Iop_64to16,cc_dep1),
                            unop(Iop_64to16,cc_dep2)));
       }
+      if (isU64(cc_op, AMD64G_CC_OP_SUBW) && isU64(cond, AMD64CondNZ)) {
+         /* word sub/cmp, then NZ --> test dst!=src */
+         return unop(Iop_1Uto64,
+                     binop(Iop_CmpNE16, 
+                           unop(Iop_64to16,cc_dep1),
+                           unop(Iop_64to16,cc_dep2)));
+      }
 
       if (isU64(cc_op, AMD64G_CC_OP_SUBW) && isU64(cond, AMD64CondLE)) {
          /* word sub/cmp, then LE (signed less than or equal) 
diff --git a/VEX/priv/guest-x86/ghelpers.c b/VEX/priv/guest-x86/ghelpers.c
index db4e3d2602..808e9f9890 100644
--- a/VEX/priv/guest-x86/ghelpers.c
+++ b/VEX/priv/guest-x86/ghelpers.c
@@ -925,6 +925,13 @@ IRExpr* guest_x86_spechelper ( HChar* function_name,
                            unop(Iop_32to16,cc_dep1), 
                            unop(Iop_32to16,cc_dep2)));
       }
+      if (isU32(cc_op, X86G_CC_OP_SUBW) && isU32(cond, X86CondNZ)) {
+         /* word sub/cmp, then NZ --> test dst!=src */
+         return unop(Iop_1Uto32,
+                     binop(Iop_CmpNE16, 
+                           unop(Iop_32to16,cc_dep1), 
+                           unop(Iop_32to16,cc_dep2)));
+      }
 
       /*---------------- SUBB ----------------*/