[llvm] [MacroFusion] Remove createBranchMacroFusionDAGMutation (PR #76209)

[Wang Pengcheng via llvm-commits]

https://github.com/wangpc-pp created https://github.com/llvm/llvm-project/pull/76209

Instead, we add a `BranchOnly` parameter to indicate that only
branches with its predecessors will be fused.

X86 is the only user of `createBranchMacroFusionDAGMutation`.


>From 2933689a23535d154802708b39485081e84585bc Mon Sep 17 00:00:00 2001
From: wangpc <wangpengcheng.pp at bytedance.com>
Date: Fri, 22 Dec 2023 14:56:50 +0800
Subject: [PATCH] [MacroFusion] Remove createBranchMacroFusionDAGMutation

Instead, we add a `BranchOnly` parameter to indicate that only
branches with its predecessors will be fused.

X86 is the only user of `createBranchMacroFusionDAGMutation`.
---
 llvm/include/llvm/CodeGen/MacroFusion.h | 12 ++++--------
 llvm/lib/CodeGen/MacroFusion.cpp        | 11 ++---------
 llvm/lib/Target/X86/X86MacroFusion.cpp  |  3 ++-
 3 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/MacroFusion.h b/llvm/include/llvm/CodeGen/MacroFusion.h
index a359fca6042600..191c906e9ef6c6 100644
--- a/llvm/include/llvm/CodeGen/MacroFusion.h
+++ b/llvm/include/llvm/CodeGen/MacroFusion.h
@@ -50,15 +50,11 @@ bool fuseInstructionPair(ScheduleDAGInstrs &DAG, SUnit &FirstSU,
 /// for instructions that benefit according to the target-specific
 /// predicate functions. shouldScheduleAdjacent will be true if any of the
 /// provided predicates are true.
+/// If BranchOnly is true, only branch instructions with one of their
+/// predecessors will be fused.
 std::unique_ptr<ScheduleDAGMutation>
-createMacroFusionDAGMutation(ArrayRef<MacroFusionPredTy> Predicates);
-
-/// Create a DAG scheduling mutation to pair branch instructions with one
-/// of their predecessors back to back for instructions that benefit according
-/// to the target-specific predicate functions. shouldScheduleAdjacent will be
-/// true if any of the provided predicates are true.
-std::unique_ptr<ScheduleDAGMutation>
-createBranchMacroFusionDAGMutation(ArrayRef<MacroFusionPredTy> Predicates);
+createMacroFusionDAGMutation(ArrayRef<MacroFusionPredTy> Predicates,
+                             bool BranchOnly = false);
 
 } // end namespace llvm
 
diff --git a/llvm/lib/CodeGen/MacroFusion.cpp b/llvm/lib/CodeGen/MacroFusion.cpp
index aff4d95781f45c..d4b02fd70084bf 100644
--- a/llvm/lib/CodeGen/MacroFusion.cpp
+++ b/llvm/lib/CodeGen/MacroFusion.cpp
@@ -212,15 +212,8 @@ bool MacroFusion::scheduleAdjacentImpl(ScheduleDAGInstrs &DAG, SUnit &AnchorSU)
 }
 
 std::unique_ptr<ScheduleDAGMutation>
-llvm::createMacroFusionDAGMutation(ArrayRef<MacroFusionPredTy> Predicates) {
+llvm::createMacroFusionDAGMutation(ArrayRef<MacroFusionPredTy> Predicates, bool BranchOnly) {
   if (EnableMacroFusion)
-    return std::make_unique<MacroFusion>(Predicates, true);
-  return nullptr;
-}
-
-std::unique_ptr<ScheduleDAGMutation> llvm::createBranchMacroFusionDAGMutation(
-    ArrayRef<MacroFusionPredTy> Predicates) {
-  if (EnableMacroFusion)
-    return std::make_unique<MacroFusion>(Predicates, false);
+    return std::make_unique<MacroFusion>(Predicates, !BranchOnly);
   return nullptr;
 }
diff --git a/llvm/lib/Target/X86/X86MacroFusion.cpp b/llvm/lib/Target/X86/X86MacroFusion.cpp
index 82667b8cdbdb87..c0fa9aa7032437 100644
--- a/llvm/lib/Target/X86/X86MacroFusion.cpp
+++ b/llvm/lib/Target/X86/X86MacroFusion.cpp
@@ -68,7 +68,8 @@ static bool shouldScheduleAdjacent(const TargetInstrInfo &TII,
 namespace llvm {
 
 std::unique_ptr<ScheduleDAGMutation> createX86MacroFusionDAGMutation() {
-  return createBranchMacroFusionDAGMutation(shouldScheduleAdjacent);
+  return createMacroFusionDAGMutation(shouldScheduleAdjacent,
+                                      /*BranchOnly=*/true);
 }
 
 } // end namespace llvm