diff options
| -rw-r--r-- | lib/Analysis/InstructionSimplify.cpp | 28 | ||||
| -rw-r--r-- | test/Transforms/Inline/inline_constprop.ll | 62 |
2 files changed, 79 insertions, 11 deletions
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 16a9a0481c..379a35ad37 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -1719,10 +1719,13 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, return ConstantInt::get(ITy, false); // A local identified object (alloca or noalias call) can't equal any - // incoming argument, unless they're both null. - if (isa<Instruction>(LHSPtr) && isa<Argument>(RHSPtr) && - Pred == CmpInst::ICMP_EQ) - return ConstantInt::get(ITy, false); + // incoming argument, unless they're both null or they belong to + // different functions. The latter happens during inlining. + if (Instruction *LHSInst = dyn_cast<Instruction>(LHSPtr)) + if (Argument *RHSArg = dyn_cast<Argument>(RHSPtr)) + if (LHSInst->getParent()->getParent() == RHSArg->getParent() && + Pred == CmpInst::ICMP_EQ) + return ConstantInt::get(ITy, false); } // Assume that the constant null is on the right. @@ -1732,14 +1735,17 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, else if (Pred == CmpInst::ICMP_NE) return ConstantInt::get(ITy, true); } - } else if (isa<Argument>(LHSPtr)) { + } else if (Argument *LHSArg = dyn_cast<Argument>(LHSPtr)) { RHSPtr = RHSPtr->stripInBoundsOffsets(); - // An alloca can't be equal to an argument. - if (isa<AllocaInst>(RHSPtr)) { - if (Pred == CmpInst::ICMP_EQ) - return ConstantInt::get(ITy, false); - else if (Pred == CmpInst::ICMP_NE) - return ConstantInt::get(ITy, true); + // An alloca can't be equal to an argument unless they come from separate + // functions via inlining. + if (AllocaInst *RHSInst = dyn_cast<AllocaInst>(RHSPtr)) { + if (LHSArg->getParent() == RHSInst->getParent()->getParent()) { + if (Pred == CmpInst::ICMP_EQ) + return ConstantInt::get(ITy, false); + else if (Pred == CmpInst::ICMP_NE) + return ConstantInt::get(ITy, true); + } } } diff --git a/test/Transforms/Inline/inline_constprop.ll b/test/Transforms/Inline/inline_constprop.ll index dc35b60ba3..0b48a7282f 100644 --- a/test/Transforms/Inline/inline_constprop.ll +++ b/test/Transforms/Inline/inline_constprop.ll @@ -110,3 +110,65 @@ bb.merge: bb.false: ret i32 %sub } + + +define i32 @PR13412.main() { +; This is a somewhat complicated three layer subprogram that was reported to +; compute the wrong value for a branch due to assuming that an argument +; mid-inline couldn't be equal to another pointer. +; +; After inlining, the branch should point directly to the exit block, not to +; the intermediate block. +; CHECK: @PR13412.main +; CHECK: br i1 true, label %[[TRUE_DEST:.*]], label %[[FALSE_DEST:.*]] +; CHECK: [[FALSE_DEST]]: +; CHECK-NEXT: call void @PR13412.fail() +; CHECK: [[TRUE_DEST]]: +; CHECK-NEXT: ret i32 0 + +entry: + %i1 = alloca i64 + store i64 0, i64* %i1 + %arraydecay = bitcast i64* %i1 to i32* + %call = call i1 @PR13412.first(i32* %arraydecay, i32* %arraydecay) + br i1 %call, label %cond.end, label %cond.false + +cond.false: + call void @PR13412.fail() + br label %cond.end + +cond.end: + ret i32 0 +} + +define internal i1 @PR13412.first(i32* %a, i32* %b) { +entry: + %call = call i32* @PR13412.second(i32* %a, i32* %b) + %cmp = icmp eq i32* %call, %b + ret i1 %cmp +} + +declare void @PR13412.fail() + +define internal i32* @PR13412.second(i32* %a, i32* %b) { +entry: + %sub.ptr.lhs.cast = ptrtoint i32* %b to i64 + %sub.ptr.rhs.cast = ptrtoint i32* %a to i64 + %sub.ptr.sub = sub i64 %sub.ptr.lhs.cast, %sub.ptr.rhs.cast + %sub.ptr.div = ashr exact i64 %sub.ptr.sub, 2 + %cmp = icmp ugt i64 %sub.ptr.div, 1 + br i1 %cmp, label %if.then, label %if.end3 + +if.then: + %0 = load i32* %a + %1 = load i32* %b + %cmp1 = icmp eq i32 %0, %1 + br i1 %cmp1, label %return, label %if.end3 + +if.end3: + br label %return + +return: + %retval.0 = phi i32* [ %b, %if.end3 ], [ %a, %if.then ] + ret i32* %retval.0 +} |