From: Julian Seward <jseward@acm.org>
Date: Sun, 17 Sep 2006 10:02:35 +0000 (+0000)
Subject: Another day, another %eflags reduction rule.
X-Git-Tag: svn/VALGRIND_3_3_1^2~96
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=76e1aa3cb5c35e89350468e8dbfd7adc0b631c5b;p=thirdparty%2Fvalgrind.git

Another day, another %eflags reduction rule.


git-svn-id: svn://svn.valgrind.org/vex/trunk@1660
---

diff --git a/VEX/priv/guest-x86/ghelpers.c b/VEX/priv/guest-x86/ghelpers.c
index 89555342b3..9cfe7379b7 100644
--- a/VEX/priv/guest-x86/ghelpers.c
+++ b/VEX/priv/guest-x86/ghelpers.c
@@ -853,6 +853,16 @@ IRExpr* guest_x86_spechelper ( HChar* function_name,
                      binop(Iop_CmpLE32S, cc_dep1, cc_dep2));
       }
 
+      if (isU32(cc_op, X86G_CC_OP_SUBL) && isU32(cond, X86CondNLE)) {
+         /* long sub/cmp, then LE (signed not less than or equal)
+            --> test dst >s src 
+            --> test !(dst <=s src) */
+         return binop(Iop_Xor32,
+                      unop(Iop_1Uto32,
+                           binop(Iop_CmpLE32S, cc_dep1, cc_dep2)),
+                      mkU32(1));
+      }
+
       if (isU32(cc_op, X86G_CC_OP_SUBL) && isU32(cond, X86CondBE)) {
          /* long sub/cmp, then BE (unsigned less than or equal)
             --> test dst <=u src */