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-rw-r--r--lib/VMCore/ConstantFold.cpp29
-rw-r--r--test/Transforms/InstCombine/2010-03-03-ExtElim.ll18
2 files changed, 23 insertions, 24 deletions
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index 47244a0e32..549977c234 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -2070,7 +2070,7 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
if (ConstantExpr *CE2 = dyn_cast<ConstantExpr>(C2)) {
Constant *CE2Op0 = CE2->getOperand(0);
if (CE2->getOpcode() == Instruction::BitCast &&
- CE2->getType()->isVectorTy()==CE2Op0->getType()->isVectorTy()) {
+ CE2->getType()->isVectorTy() == CE2Op0->getType()->isVectorTy()) {
Constant *Inverse = ConstantExpr::getBitCast(C1, CE2Op0->getType());
return ConstantExpr::getICmp(pred, Inverse, CE2Op0);
}
@@ -2078,8 +2078,8 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
// If the left hand side is an extension, try eliminating it.
if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
- if (CE1->getOpcode() == Instruction::SExt ||
- CE1->getOpcode() == Instruction::ZExt) {
+ if ((CE1->getOpcode() == Instruction::SExt && ICmpInst::isSigned(pred)) ||
+ (CE1->getOpcode() == Instruction::ZExt && !ICmpInst::isSigned(pred))){
Constant *CE1Op0 = CE1->getOperand(0);
Constant *CE1Inverse = ConstantExpr::getTrunc(CE1, CE1Op0->getType());
if (CE1Inverse == CE1Op0) {
@@ -2097,27 +2097,8 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
// If C2 is a constant expr and C1 isn't, flip them around and fold the
// other way if possible.
// Also, if C1 is null and C2 isn't, flip them around.
- switch (pred) {
- case ICmpInst::ICMP_EQ:
- case ICmpInst::ICMP_NE:
- // No change of predicate required.
- return ConstantExpr::getICmp(pred, C2, C1);
-
- case ICmpInst::ICMP_ULT:
- case ICmpInst::ICMP_SLT:
- case ICmpInst::ICMP_UGT:
- case ICmpInst::ICMP_SGT:
- case ICmpInst::ICMP_ULE:
- case ICmpInst::ICMP_SLE:
- case ICmpInst::ICMP_UGE:
- case ICmpInst::ICMP_SGE:
- // Change the predicate as necessary to swap the operands.
- pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred);
- return ConstantExpr::getICmp(pred, C2, C1);
-
- default: // These predicates cannot be flopped around.
- break;
- }
+ pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred);
+ return ConstantExpr::getICmp(pred, C2, C1);
}
}
return 0;
diff --git a/test/Transforms/InstCombine/2010-03-03-ExtElim.ll b/test/Transforms/InstCombine/2010-03-03-ExtElim.ll
new file mode 100644
index 0000000000..2df12d670a
--- /dev/null
+++ b/test/Transforms/InstCombine/2010-03-03-ExtElim.ll
@@ -0,0 +1,18 @@
+; RUN: opt -instcombine -S %s | FileCheck %s
+; PR6486
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
+target triple = "i386-unknown-linux-gnu"
+
+@g_92 = common global [2 x i32*] zeroinitializer, align 4 ; <[2 x i32*]*> [#uses=1]
+@g_177 = constant i32** bitcast (i8* getelementptr (i8* bitcast ([2 x i32*]* @g_92 to i8*), i64 4) to i32**), align 4 ; <i32***> [#uses=1]
+
+define i1 @test() nounwind {
+; CHECK: @test
+ %tmp = load i32*** @g_177 ; <i32**> [#uses=1]
+ %cmp = icmp ne i32** null, %tmp ; <i1> [#uses=1]
+ %conv = zext i1 %cmp to i32 ; <i32> [#uses=1]
+ %cmp1 = icmp sle i32 0, %conv ; <i1> [#uses=1]
+ ret i1 %cmp1
+; CHECK: ret i1 true
+}