[PATCH] D89423: Explicitly check for entry basic block, rather than relying on MachineBasicBlock::pred_empty.

[Sriraman Tallam via Phabricator via llvm-commits]

tmsriram added inline comments.


================
Comment at: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:3092
   // Print the main label for the block.
-  if (MBB.pred_empty() ||
-      (!MF->hasBBLabels() && isBlockOnlyReachableByFallthrough(&MBB) &&
-       !MBB.isEHFuncletEntry() && !MBB.hasLabelMustBeEmitted())) {
+  if (shouldEmitLabelForBasicBlock(MBB)) {
+    if (isVerbose() && MBB.hasLabelMustBeEmitted())
----------------
Should we keep the same order as before? Any reason to flip it?  I don't have a strong opinion but the change is simpler.


================
Comment at: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:3142
+/// shouldEmitLabelForBasicBlock - Return true if the given basic block requires
+/// basic block label. The symbol is constructed later by a call to
+/// MachineBasicBlock::getSymbol and may assume different names under various
----------------



================
Comment at: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:3144
+/// MachineBasicBlock::getSymbol and may assume different names under various
+/// circumstances.
+bool AsmPrinter::shouldEmitLabelForBasicBlock(
----------------
"assume different names under various circumstances" , please rephrase.


================
Comment at: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:3147
+    const MachineBasicBlock &MBB) const {
+  // With -basic-block-sections, a label is needed for every non-entry block in
+  // the 'labels' mode and every section beginning in the 'sections' mode.
----------------



================
Comment at: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:3148
+  // With -basic-block-sections, a label is needed for every non-entry block in
+  // the 'labels' mode and every section beginning in the 'sections' mode.
+  if ((MF->hasBBLabels() || MBB.isBeginSection()) && !MBB.isEntryBlock())
----------------



================
Comment at: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:3152
+  // A label is needed for any block with at least one predecessor (when that
+  // predecessor is not the fallthrough predecessor, or if other conditions are
+  // met).
----------------



Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89423/new/

https://reviews.llvm.org/D89423