[llvm-commits] [llvm] r130954 - in /llvm/trunk: lib/Analysis/InstructionSimplify.cpp lib/Transforms/InstCombine/InstCombineCompares.cpp test/Transforms/InstCombine/icmp.ll

[Eli Friedman]

Author: efriedma
Date: Thu May  5 16:59:18 2011
New Revision: 130954

URL: http://llvm.org/viewvc/llvm-project?rev=130954&view=rev
Log:
PR9838: Fix transform introduced in r127064 to not trigger when only one side of the icmp is an exact shift.


Modified:
    llvm/trunk/lib/Analysis/InstructionSimplify.cpp
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
    llvm/trunk/test/Transforms/InstCombine/icmp.ll

Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=130954&r1=130953&r2=130954&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Thu May  5 16:59:18 2011
@@ -1847,7 +1847,7 @@
       // fall-through
     case Instruction::SDiv:
     case Instruction::AShr:
-      if (!LBO->isExact() && !RBO->isExact())
+      if (!LBO->isExact() || !RBO->isExact())
         break;
       if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
                                       RBO->getOperand(0), TD, DT, MaxRecurse-1))

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=130954&r1=130953&r2=130954&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Thu May  5 16:59:18 2011
@@ -2400,7 +2400,7 @@
         // fall-through
       case Instruction::SDiv:
       case Instruction::AShr:
-        if (!BO0->isExact() && !BO1->isExact())
+        if (!BO0->isExact() || !BO1->isExact())
           break;
         return new ICmpInst(I.getPredicate(), BO0->getOperand(0),
                             BO1->getOperand(0));

Modified: llvm/trunk/test/Transforms/InstCombine/icmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/icmp.ll?rev=130954&r1=130953&r2=130954&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/icmp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/icmp.ll Thu May  5 16:59:18 2011
@@ -510,3 +510,14 @@
   ret i1 %A
 }
 
+; PR9838
+; CHECK: @test53
+; CHECK-NEXT: ashr exact
+; CHECK-NEXT: ashr
+; CHECK-NEXT: icmp
+define i1 @test53(i32 %a, i32 %b) nounwind {
+ %x = ashr exact i32 %a, 30
+ %y = ashr i32 %b, 30
+ %z = icmp eq i32 %x, %y
+ ret i1 %z
+}