Fix PR1817.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44284 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index e8cd86778ae45896a6bcce690ae8e52f39c37ffc..c8df4128643282f3918777630498c82ec03bb929 100644 (file)
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -3463,7 +3463,12 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
             LHSCC != ICmpInst::ICMP_UGE && LHSCC != ICmpInst::ICMP_ULE &&
             RHSCC != ICmpInst::ICMP_UGE && RHSCC != ICmpInst::ICMP_ULE &&
             LHSCC != ICmpInst::ICMP_SGE && LHSCC != ICmpInst::ICMP_SLE &&
-            RHSCC != ICmpInst::ICMP_SGE && RHSCC != ICmpInst::ICMP_SLE) {
+            RHSCC != ICmpInst::ICMP_SGE && RHSCC != ICmpInst::ICMP_SLE &&
+            
+            // Don't try to fold ICMP_SLT + ICMP_ULT.
+            (ICmpInst::isEquality(LHSCC) || ICmpInst::isEquality(RHSCC) ||
+             ICmpInst::isSignedPredicate(LHSCC) == 
+                 ICmpInst::isSignedPredicate(RHSCC))) {
           // Ensure that the larger constant is on the RHS.
           ICmpInst::Predicate GT = ICmpInst::isSignedPredicate(LHSCC) ? 
             ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;

diff --git a/test/Transforms/InstCombine/2007-11-22-IcmpCrash.ll b/test/Transforms/InstCombine/2007-11-22-IcmpCrash.ll
new file mode 100644 (file)
index 0000000..1f211b6
--- /dev/null
+++ b/test/Transforms/InstCombine/2007-11-22-IcmpCrash.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output
+; PR1817
+
+define i1 @test1(i32 %X) {
+       %A = icmp slt i32 %X, 10
+       %B = icmp ult i32 %X, 10
+       %C = and i1 %A, %B
+       ret i1 %C
+}
+
+define i1 @test2(i32 %X) {
+       %A = icmp slt i32 %X, 10
+       %B = icmp ult i32 %X, 10
+       %C = or i1 %A, %B
+       ret i1 %C
+}