From: Julian Seward <jseward@acm.org>
Date: Fri, 23 Sep 2011 15:04:29 +0000 (+0000)
Subject: Add a couple of spec rules for MI and PL after LOGIC.  These are
X-Git-Tag: svn/VALGRIND_3_7_0^2~18
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=96b712612639747bd1a88755f5b72aa038588276;p=thirdparty%2Fvalgrind.git

Add a couple of spec rules for MI and PL after LOGIC.  These are
important for avoiding false positives in Android syscall handlers.


git-svn-id: svn://svn.valgrind.org/vex/trunk@2206
---

diff --git a/VEX/priv/guest_arm_helpers.c b/VEX/priv/guest_arm_helpers.c
index 8aae1b34fb..f5ed31038f 100644
--- a/VEX/priv/guest_arm_helpers.c
+++ b/VEX/priv/guest_arm_helpers.c
@@ -676,6 +676,21 @@ IRExpr* guest_arm_spechelper ( HChar*   function_name,
                      binop(Iop_CmpNE32, cc_dep1, mkU32(0)));
       }
 
+      if (isU32(cond_n_op, (ARMCondPL << 4) | ARMG_CC_OP_LOGIC)) {
+         /* PL after LOGIC --> test (res >> 31) == 0 */
+         return unop(Iop_1Uto32,
+                     binop(Iop_CmpEQ32,
+                           binop(Iop_Shr32, cc_dep1, mkU8(31)),
+                           mkU32(0)));
+      }
+      if (isU32(cond_n_op, (ARMCondMI << 4) | ARMG_CC_OP_LOGIC)) {
+         /* MI after LOGIC --> test (res >> 31) == 1 */
+         return unop(Iop_1Uto32,
+                     binop(Iop_CmpEQ32,
+                           binop(Iop_Shr32, cc_dep1, mkU8(31)),
+                           mkU32(1)));
+      }
+
       /*----------------- AL -----------------*/
 
       /* A critically important case for Thumb code.