Reapply 68073, with fixes. EH Landing-pad basic blocks are not
entered via fall-through. Don't miss fallthroughs from blocks
terminated by conditional branches. Also, move
isOnlyReachableByFallthrough out of line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68129 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 51f0f9d..5ac54ea8 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -123,6 +123,16 @@
return I;
}
+bool
+MachineBasicBlock::isOnlyReachableByFallthrough() const {
+ return !isLandingPad() &&
+ !pred_empty() &&
+ next(pred_begin()) == pred_end() &&
+ (*pred_begin())->isLayoutSuccessor(this) &&
+ ((*pred_begin())->empty() ||
+ !(*pred_begin())->back().getDesc().isBarrier());
+}
+
void MachineBasicBlock::dump() const {
print(*cerr.stream());
}
diff --git a/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp b/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
index 3bdcf88..3b6b0ef 100644
--- a/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
+++ b/lib/Target/X86/AsmPrinter/X86ATTAsmPrinter.cpp
@@ -238,7 +238,10 @@
for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
I != E; ++I) {
// Print a label for the basic block.
- if (!I->pred_empty()) {
+ if (!VerboseAsm && (I->pred_empty() || I->isOnlyReachableByFallthrough())) {
+ // This is an entry block or a block that's only reachable via a
+ // fallthrough edge. In non-VerboseAsm mode, don't print the label.
+ } else {
printBasicBlockLabel(I, true, true, VerboseAsm);
O << '\n';
}