Index: llvm/trunk/lib/Analysis/ConstantFolding.cpp =================================================================== --- llvm/trunk/lib/Analysis/ConstantFolding.cpp +++ llvm/trunk/lib/Analysis/ConstantFolding.cpp @@ -1170,7 +1170,9 @@ const DataLayout &DL, const TargetLibraryInfo *TLI) { // fold: icmp (inttoptr x), null -> icmp x, 0 + // fold: icmp null, (inttoptr x) -> icmp 0, x // fold: icmp (ptrtoint x), 0 -> icmp x, null + // fold: icmp 0, (ptrtoint x) -> icmp null, x // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y // @@ -1240,6 +1242,11 @@ Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or; return ConstantFoldBinaryOpOperands(OpC, LHS, RHS, DL); } + } else if (isa(Ops1)) { + // If RHS is a constant expression, but the left side isn't, swap the + // operands and try again. + Predicate = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)Predicate); + return ConstantFoldCompareInstOperands(Predicate, Ops1, Ops0, DL, TLI); } return ConstantExpr::getCompare(Predicate, Ops0, Ops1); Index: llvm/trunk/test/Transforms/InstSimplify/compare.ll =================================================================== --- llvm/trunk/test/Transforms/InstSimplify/compare.ll +++ llvm/trunk/test/Transforms/InstSimplify/compare.ll @@ -1289,7 +1289,7 @@ define i1 @constant_fold_null_inttoptr() { ; CHECK-LABEL: @constant_fold_null_inttoptr( -; CHECK-NEXT: ret i1 icmp eq (i32* inttoptr (i64 32 to i32*), i32* null) +; CHECK-NEXT: ret i1 false ; %x = icmp eq i32* null, inttoptr (i64 32 to i32*) ret i1 %x