diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/Transforms/SimplifyCFG/switch_msan.ll | 102 |
2 files changed, 108 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 3a18b52a4de..bcf52198e94 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -3729,12 +3729,17 @@ static bool SimplifyBranchOnICmpChain(BranchInst *BI, IRBuilder<> &Builder, BasicBlock *BB = BI->getParent(); + // MSAN does not like undefs as branch condition which can be introduced + // with "explicit branch". + if (ExtraCase && BB->getParent()->hasFnAttribute(Attribute::SanitizeMemory)) + return false; + LLVM_DEBUG(dbgs() << "Converting 'icmp' chain with " << Values.size() << " cases into SWITCH. BB is:\n" << *BB); // If there are any extra values that couldn't be folded into the switch - // then we evaluate them with an explicit branch first. Split the block + // then we evaluate them with an explicit branch first. Split the block // right before the condbr to handle it. if (ExtraCase) { BasicBlock *NewBB = diff --git a/llvm/test/Transforms/SimplifyCFG/switch_msan.ll b/llvm/test/Transforms/SimplifyCFG/switch_msan.ll new file mode 100644 index 00000000000..96e79828977 --- /dev/null +++ b/llvm/test/Transforms/SimplifyCFG/switch_msan.ll @@ -0,0 +1,102 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -S -simplifycfg < %s | FileCheck %s + +declare i8 @next_char(); + +define void @test_no_msan() { +; CHECK-LABEL: @test_no_msan( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[WHILE_BODY:%.*]] +; CHECK: while.body: +; CHECK-NEXT: br label [[WHILE_BODY_I:%.*]] +; CHECK: while.body.i: +; CHECK-NEXT: [[MAYBE_UNDEF:%.*]] = phi i1 [ undef, [[WHILE_BODY]] ], [ [[NEXT_MAYBE_UNDEF:%.*]], [[WHILE_BODY_I]] ] +; CHECK-NEXT: [[C:%.*]] = call fastcc signext i8 @next_char() +; CHECK-NEXT: [[C_10:%.*]] = icmp eq i8 [[C]], 10 +; CHECK-NEXT: [[C_13:%.*]] = icmp eq i8 [[C]], 13 +; CHECK-NEXT: [[C_10_OR_13:%.*]] = or i1 [[C_10]], [[C_13]] +; CHECK-NEXT: [[NEXT_MAYBE_UNDEF]] = or i1 [[MAYBE_UNDEF]], [[C_10_OR_13]] +; CHECK-NEXT: [[C_NOT_10_OR_13:%.*]] = xor i1 [[C_10_OR_13]], true +; CHECK-NEXT: br i1 [[C_NOT_10_OR_13]], label [[WHILE_BODY_I]], label [[WHILE_BODY_I_BREAK:%.*]] +; CHECK: while.body.i.break: +; CHECK-NEXT: br i1 [[MAYBE_UNDEF]], label [[WHILE_BODY]], label [[SWITCH_EARLY_TEST:%.*]] +; CHECK: switch.early.test: +; CHECK-NEXT: switch i8 [[C]], label [[RETURN:%.*]] [ +; CHECK-NEXT: i8 13, label [[WHILE_BODY]] +; CHECK-NEXT: i8 10, label [[WHILE_BODY]] +; CHECK-NEXT: ] +; CHECK: return: +; CHECK-NEXT: ret void +; + +entry: + br label %while.body + +while.body: + br label %while.body.i + +while.body.i: + %maybe_undef = phi i1 [ undef, %while.body ], [ %next_maybe_undef, %while.body.i ] + %c = call fastcc signext i8 @next_char() + %c_10 = icmp eq i8 %c, 10 + %c_13 = icmp eq i8 %c, 13 + %c_10_or_13 = or i1 %c_10, %c_13 + %next_maybe_undef = or i1 %maybe_undef, %c_10_or_13 + %c_not_10_or_13 = xor i1 %c_10_or_13, true + br i1 %c_not_10_or_13, label %while.body.i, label %while.body.i.break + +while.body.i.break: + ; NEXT_MAYBE_UNDEF is never undef if here + br i1 %next_maybe_undef, label %while.body, label %return + + +return: + ret void +} + + +define void @test_msan() sanitize_memory { +; CHECK-LABEL: @test_msan( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[WHILE_BODY:%.*]] +; CHECK: while.body: +; CHECK-NEXT: br label [[WHILE_BODY_I:%.*]] +; CHECK: while.body.i: +; CHECK-NEXT: [[MAYBE_UNDEF:%.*]] = phi i1 [ undef, [[WHILE_BODY]] ], [ [[NEXT_MAYBE_UNDEF:%.*]], [[WHILE_BODY_I]] ] +; CHECK-NEXT: [[C:%.*]] = call fastcc signext i8 @next_char() +; CHECK-NEXT: [[C_10:%.*]] = icmp eq i8 [[C]], 10 +; CHECK-NEXT: [[C_13:%.*]] = icmp eq i8 [[C]], 13 +; CHECK-NEXT: [[C_10_OR_13:%.*]] = or i1 [[C_10]], [[C_13]] +; CHECK-NEXT: [[NEXT_MAYBE_UNDEF]] = or i1 [[MAYBE_UNDEF]], [[C_10_OR_13]] +; CHECK-NEXT: [[C_NOT_10_OR_13:%.*]] = xor i1 [[C_10_OR_13]], true +; CHECK-NEXT: br i1 [[C_NOT_10_OR_13]], label [[WHILE_BODY_I]], label [[WHILE_BODY_I_BREAK:%.*]] +; CHECK: while.body.i.break: +; CHECK-NEXT: br i1 [[NEXT_MAYBE_UNDEF]], label [[WHILE_BODY]], label [[RETURN:%.*]] +; CHECK: return: +; CHECK-NEXT: ret void +; + +entry: + br label %while.body + +while.body: + br label %while.body.i + +while.body.i: + %maybe_undef = phi i1 [ undef, %while.body ], [ %next_maybe_undef, %while.body.i ] + %c = call fastcc signext i8 @next_char() + %c_10 = icmp eq i8 %c, 10 + %c_13 = icmp eq i8 %c, 13 + %c_10_or_13 = or i1 %c_10, %c_13 + %next_maybe_undef = or i1 %maybe_undef, %c_10_or_13 + %c_not_10_or_13 = xor i1 %c_10_or_13, true + br i1 %c_not_10_or_13, label %while.body.i, label %while.body.i.break + +while.body.i.break: + ; NEXT_MAYBE_UNDEF is never undef if here + br i1 %next_maybe_undef, label %while.body, label %return + + +return: + ret void +} |
