From bdb4012fe3f9e30e2ea3e1d92524ad7725b2957e Mon Sep 17 00:00:00 2001
From: Philip Reames <preames@rivosinc.com>
Date: Fri, 14 Mar 2025 09:04:52 -0700
Subject: [PATCH] [CodeGen] Remove parameter from
 LiveRangeEdit::canRematerializeAt [NFC]

Only one caller cares about the true case of this parameter, so move
the check to that single caller.  Note that RegisterCoalescer seems
like it should care, but it already duplicates the check several
lines above.
---
 llvm/include/llvm/CodeGen/LiveRangeEdit.h | 4 +---
 llvm/lib/CodeGen/InlineSpiller.cpp        | 2 +-
 llvm/lib/CodeGen/LiveRangeEdit.cpp        | 6 +-----
 llvm/lib/CodeGen/RegisterCoalescer.cpp    | 2 +-
 llvm/lib/CodeGen/SplitKit.cpp             | 6 ++----
 5 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/LiveRangeEdit.h b/llvm/include/llvm/CodeGen/LiveRangeEdit.h
index 3a4a76d99c5c..3d5df194c71c 100644
--- a/llvm/include/llvm/CodeGen/LiveRangeEdit.h
+++ b/llvm/include/llvm/CodeGen/LiveRangeEdit.h
@@ -200,9 +200,7 @@ public:
 
   /// canRematerializeAt - Determine if ParentVNI can be rematerialized at
   /// UseIdx. It is assumed that parent_.getVNINfoAt(UseIdx) == ParentVNI.
-  /// When cheapAsAMove is set, only cheap remats are allowed.
-  bool canRematerializeAt(Remat &RM, VNInfo *OrigVNI, SlotIndex UseIdx,
-                          bool cheapAsAMove);
+  bool canRematerializeAt(Remat &RM, VNInfo *OrigVNI, SlotIndex UseIdx);
 
   /// rematerializeAt - Rematerialize RM.ParentVNI into DestReg by inserting an
   /// instruction into MBB before MI. The new instruction is mapped, but
diff --git a/llvm/lib/CodeGen/InlineSpiller.cpp b/llvm/lib/CodeGen/InlineSpiller.cpp
index 4a49665ada3c..ec71d504ebab 100644
--- a/llvm/lib/CodeGen/InlineSpiller.cpp
+++ b/llvm/lib/CodeGen/InlineSpiller.cpp
@@ -644,7 +644,7 @@ bool InlineSpiller::reMaterializeFor(LiveInterval &VirtReg, MachineInstr &MI) {
   LiveRangeEdit::Remat RM(ParentVNI);
   RM.OrigMI = LIS.getInstructionFromIndex(OrigVNI->def);
 
-  if (!Edit->canRematerializeAt(RM, OrigVNI, UseIdx, false)) {
+  if (!Edit->canRematerializeAt(RM, OrigVNI, UseIdx)) {
     markValueUsed(&VirtReg, ParentVNI);
     LLVM_DEBUG(dbgs() << "\tcannot remat for " << UseIdx << '\t' << MI);
     return false;
diff --git a/llvm/lib/CodeGen/LiveRangeEdit.cpp b/llvm/lib/CodeGen/LiveRangeEdit.cpp
index 0b637bf8a9c5..a3858efbdc5e 100644
--- a/llvm/lib/CodeGen/LiveRangeEdit.cpp
+++ b/llvm/lib/CodeGen/LiveRangeEdit.cpp
@@ -156,7 +156,7 @@ bool LiveRangeEdit::allUsesAvailableAt(const MachineInstr *OrigMI,
 }
 
 bool LiveRangeEdit::canRematerializeAt(Remat &RM, VNInfo *OrigVNI,
-                                       SlotIndex UseIdx, bool cheapAsAMove) {
+                                       SlotIndex UseIdx) {
   assert(ScannedRemattable && "Call anyRematerializable first");
 
   // Use scanRemattable info.
@@ -168,10 +168,6 @@ bool LiveRangeEdit::canRematerializeAt(Remat &RM, VNInfo *OrigVNI,
   assert(RM.OrigMI && "No defining instruction for remattable value");
   DefIdx = LIS.getInstructionIndex(*RM.OrigMI);
 
-  // If only cheap remats were requested, bail out early.
-  if (cheapAsAMove && !TII.isAsCheapAsAMove(*RM.OrigMI))
-    return false;
-
   // Verify that all used registers are available with the same values.
   if (!allUsesAvailableAt(RM.OrigMI, DefIdx, UseIdx))
     return false;
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp
index 74606e66d4e4..dbd354f2ca2c 100644
--- a/llvm/lib/CodeGen/RegisterCoalescer.cpp
+++ b/llvm/lib/CodeGen/RegisterCoalescer.cpp
@@ -1398,7 +1398,7 @@ bool RegisterCoalescer::reMaterializeTrivialDef(const CoalescerPair &CP,
 
   LiveRangeEdit::Remat RM(ValNo);
   RM.OrigMI = DefMI;
-  if (!Edit.canRematerializeAt(RM, ValNo, CopyIdx, true))
+  if (!Edit.canRematerializeAt(RM, ValNo, CopyIdx))
     return false;
 
   DebugLoc DL = CopyMI->getDebugLoc();
diff --git a/llvm/lib/CodeGen/SplitKit.cpp b/llvm/lib/CodeGen/SplitKit.cpp
index bdccbffe90f9..e55dfaebd028 100644
--- a/llvm/lib/CodeGen/SplitKit.cpp
+++ b/llvm/lib/CodeGen/SplitKit.cpp
@@ -591,9 +591,6 @@ SlotIndex SplitEditor::buildCopy(Register FromReg, Register ToReg,
 bool SplitEditor::rematWillIncreaseRestriction(const MachineInstr *DefMI,
                                                MachineBasicBlock &MBB,
                                                SlotIndex UseIdx) const {
-  if (!DefMI)
-    return false;
-
   const MachineInstr *UseMI = LIS.getInstructionFromIndex(UseIdx);
   if (!UseMI)
     return false;
@@ -640,7 +637,8 @@ VNInfo *SplitEditor::defFromParent(unsigned RegIdx, const VNInfo *ParentVNI,
   if (OrigVNI) {
     LiveRangeEdit::Remat RM(ParentVNI);
     RM.OrigMI = LIS.getInstructionFromIndex(OrigVNI->def);
-    if (Edit->canRematerializeAt(RM, OrigVNI, UseIdx, true)) {
+    if (RM.OrigMI && TII.isAsCheapAsAMove(*RM.OrigMI) &&
+        Edit->canRematerializeAt(RM, OrigVNI, UseIdx)) {
       if (!rematWillIncreaseRestriction(RM.OrigMI, MBB, UseIdx)) {
         SlotIndex Def = Edit->rematerializeAt(MBB, I, Reg, RM, TRI, Late);
         ++NumRemats;