[GlobalISel] Micro-optimize the conditional branch optimization.
Convert a check into an assert and pass an MI instead of recomputing in the
apply function.
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h b/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
index 06bbeeb..f931930 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
@@ -163,8 +163,8 @@
/// If a brcond's true block is not the fallthrough, make it so by inverting
/// the condition and swapping operands.
- bool matchOptBrCondByInvertingCond(MachineInstr &MI);
- void applyOptBrCondByInvertingCond(MachineInstr &MI);
+ bool matchOptBrCondByInvertingCond(MachineInstr &MI, MachineInstr *&BrCond);
+ void applyOptBrCondByInvertingCond(MachineInstr &MI, MachineInstr *&BrCond);
/// If \p MI is G_CONCAT_VECTORS, try to combine it.
/// Returns true if MI changed.
diff --git a/llvm/include/llvm/Target/GlobalISel/Combine.td b/llvm/include/llvm/Target/GlobalISel/Combine.td
index a63b9b8..a8c64e0 100644
--- a/llvm/include/llvm/Target/GlobalISel/Combine.td
+++ b/llvm/include/llvm/Target/GlobalISel/Combine.td
@@ -149,11 +149,12 @@
[{ return Helper.matchCombineIndexedLoadStore(*${root}, ${matchinfo}); }]),
(apply [{ Helper.applyCombineIndexedLoadStore(*${root}, ${matchinfo}); }])>;
+def opt_brcond_by_inverting_cond_matchdata : GIDefMatchData<"MachineInstr *">;
def opt_brcond_by_inverting_cond : GICombineRule<
- (defs root:$root),
+ (defs root:$root, opt_brcond_by_inverting_cond_matchdata:$matchinfo),
(match (wip_match_opcode G_BR):$root,
- [{ return Helper.matchOptBrCondByInvertingCond(*${root}); }]),
- (apply [{ Helper.applyOptBrCondByInvertingCond(*${root}); }])>;
+ [{ return Helper.matchOptBrCondByInvertingCond(*${root}, ${matchinfo}); }]),
+ (apply [{ Helper.applyOptBrCondByInvertingCond(*${root}, ${matchinfo}); }])>;
def ptr_add_immed_matchdata : GIDefMatchData<"PtrAddChain">;
def ptr_add_immed_chain : GICombineRule<
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
index e3af0c4..c4678f6 100644
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -1033,9 +1033,9 @@
OtherMI->eraseFromParent();
}
-bool CombinerHelper::matchOptBrCondByInvertingCond(MachineInstr &MI) {
- if (MI.getOpcode() != TargetOpcode::G_BR)
- return false;
+bool CombinerHelper::matchOptBrCondByInvertingCond(MachineInstr &MI,
+ MachineInstr *&BrCond) {
+ assert(MI.getOpcode() == TargetOpcode::G_BR);
// Try to match the following:
// bb1:
@@ -1056,7 +1056,7 @@
return false;
assert(std::next(BrIt) == MBB->end() && "expected G_BR to be a terminator");
- MachineInstr *BrCond = &*std::prev(BrIt);
+ BrCond = &*std::prev(BrIt);
if (BrCond->getOpcode() != TargetOpcode::G_BRCOND)
return false;
@@ -1067,11 +1067,9 @@
MBB->isLayoutSuccessor(BrCondTarget);
}
-void CombinerHelper::applyOptBrCondByInvertingCond(MachineInstr &MI) {
+void CombinerHelper::applyOptBrCondByInvertingCond(MachineInstr &MI,
+ MachineInstr *&BrCond) {
MachineBasicBlock *BrTarget = MI.getOperand(0).getMBB();
- MachineBasicBlock::iterator BrIt(MI);
- MachineInstr *BrCond = &*std::prev(BrIt);
-
Builder.setInstrAndDebugLoc(*BrCond);
LLT Ty = MRI.getType(BrCond->getOperand(0).getReg());
// FIXME: Does int/fp matter for this? If so, we might need to restrict
