Change the INLINEASM_BR MachineInstr to be a non-terminating instruction.

Before this instruction supported output values, it fit fairly
naturally as a terminator. However, being a terminator while also
supporting outputs causes some trouble, as the physreg->vreg COPY
operations cannot be in the same block.

Modeling it as a non-terminator allows it to be handled the same way
as invoke is handled already.

Most of the changes here were created by auditing all the existing
users of MachineBasicBlock::isEHPad() and
MachineBasicBlock::hasEHPadSuccessor(), and adding calls to
isInlineAsmBrIndirectTarget or mayHaveInlineAsmBr, as appropriate.

Reviewed By: nickdesaulniers, void

Differential Revision: https://reviews.llvm.org/D79794

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index e848741..2d4b604 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -277,8 +277,16 @@ LLVM_DUMP_METHOD void MachineBasicBlock::dump() const {
 }
 #endif
 
+bool MachineBasicBlock::mayHaveInlineAsmBr() const {
+  for (const MachineBasicBlock *Succ : successors()) {
+    if (Succ->isInlineAsmBrIndirectTarget())
+      return true;
+  }
+  return false;
+}
+
 bool MachineBasicBlock::isLegalToHoistInto() const {
-  if (isReturnBlock() || hasEHPadSuccessor())
+  if (isReturnBlock() || hasEHPadSuccessor() || mayHaveInlineAsmBr())
     return false;
   return true;
 }
@@ -1132,7 +1140,7 @@ bool MachineBasicBlock::canSplitCriticalEdge(
 
   // Splitting the critical edge to a callbr's indirect block isn't advised.
   // Don't do it in this generic function.
-  if (isInlineAsmBrIndirectTarget(Succ))
+  if (Succ->isInlineAsmBrIndirectTarget())
     return false;
 
   const MachineFunction *MF = getParent();