diff options
| -rw-r--r-- | llvm/lib/CodeGen/MIRPrinter.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/CodeGen/MIR/X86/unreachable_block.ll | 48 |
2 files changed, 2 insertions, 49 deletions
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp index 6347e6da942..db9ccef8a36 100644 --- a/llvm/lib/CodeGen/MIRPrinter.cpp +++ b/llvm/lib/CodeGen/MIRPrinter.cpp @@ -598,7 +598,8 @@ void MIPrinter::print(const MachineBasicBlock &MBB) { bool HasLineAttributes = false; // Print the successors bool canPredictProbs = canPredictBranchProbabilities(MBB); - if (!SimplifyMIR || !canPredictProbs || !canPredictSuccessors(MBB)) { + if (!MBB.succ_empty() && (!SimplifyMIR || !canPredictProbs || + !canPredictSuccessors(MBB))) { OS.indent(2) << "successors: "; for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I) { if (I != MBB.succ_begin()) diff --git a/llvm/test/CodeGen/MIR/X86/unreachable_block.ll b/llvm/test/CodeGen/MIR/X86/unreachable_block.ll deleted file mode 100644 index 4cea0392255..00000000000 --- a/llvm/test/CodeGen/MIR/X86/unreachable_block.ll +++ /dev/null @@ -1,48 +0,0 @@ -; RUN: llc -mtriple x86_64-- -stop-before peephole-opt -o %t.mir %s -; RUN: llc -mtriple x86_64-- -run-pass none %t.mir -verify-machineinstrs -o - | FileCheck %s - -; Unreachable blocks in the machine instr representation are these -; weird empty blocks with no successors. -; The MIR printer used to not print empty lists of successors. However, -; the MIR parser now treats non-printed list of successors as "please -; guess it for me". As a result, the parser tries to guess the list of -; successors and given the block is empty, just assumes it falls through -; the next block. -; -; The following test case used to fail the verifier because the false -; path ended up falling through split.true and now, the definition of -; %v does not dominate all its uses. -; Indeed, we go from the following CFG: -; entry -; / \ -; true (def) false -; | -; split.true (use) -; -; To this one: -; entry -; / \ -; true (def) false -; | / <-- invalid edge -; split.true (use) -; -; Because of the invalid edge, we get the "def does not -; dominate all uses" error. -; -; CHECK-LABEL: name: foo -; CHECK-LABEL: bb.{{[0-9]+}}.false: -; CHECK-NEXT: successors: -; CHECK-NOT: %bb.{{[0-9]+}}.split.true -; CHECK-LABEL: bb.{{[0-9]+}}.split.true: -define void @foo(i32* %bar) { - br i1 undef, label %true, label %false -true: - %v = load i32, i32* %bar - br label %split.true -false: - unreachable -split.true: - %vInc = add i32 %v, 1 - store i32 %vInc, i32* %bar - ret void -} |
