From: Chris Lattner <sabre@nondot.org>
Date: Mon, 16 Jul 2007 04:15:34 +0000 (+0000)
Subject: Repair a regression in Transforms/InstCombine/mul.ll that Reid noticed.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=cb7122bb7d6f8191904c3d6e646bffc0282afa68;p=oota-llvm.git

Repair a regression in Transforms/InstCombine/mul.ll that Reid noticed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39896 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index f5a85751eaa..77cb18584f9 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -2286,9 +2286,22 @@ static bool isSignBitCheck(ICmpInst::Predicate pred, ConstantInt *RHS,
   case ICmpInst::ICMP_SLT:   // True if LHS s< 0
     TrueIfSigned = true;
     return RHS->isZero();
+  case ICmpInst::ICMP_SLE:   // True if LHS s<= RHS and RHS == -1
+    TrueIfSigned = true;
+    return RHS->isAllOnesValue();
   case ICmpInst::ICMP_SGT:   // True if LHS s> -1
     TrueIfSigned = false;
     return RHS->isAllOnesValue();
+  case ICmpInst::ICMP_UGT:
+    // True if LHS u> RHS and RHS == high-bit-mask - 1
+    TrueIfSigned = true;
+    return RHS->getValue() ==
+      APInt::getSignedMaxValue(RHS->getType()->getPrimitiveSizeInBits());
+  case ICmpInst::ICMP_UGE: 
+    // True if LHS u>= RHS and RHS == high-bit-mask (2^7, 2^15, 2^31, etc)
+    TrueIfSigned = true;
+    return RHS->getValue() == 
+      APInt::getSignBit(RHS->getType()->getPrimitiveSizeInBits());
   default:
     return false;
   }