[InlineSpiller] Check rematerialization before folding operand (#134015)

Current implementation tries to fold the operand before
rematerialization because it can reduce one register usage. But if there
is a physical register available we can still rematerialize it without
causing high register pressure.

This patch do this check to find the better choice. Then we can produce

    xorps %xmm1, %xmm1
    ucomiss %xmm1, %xmm0

instead of 

    ucomiss LCPI0_1(%rip), %xmm0

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/RegAllocGreedy.cpp b/llvm/lib/CodeGen/RegAllocGreedy.cpp
index 56d3bd9..250776e 100644
--- a/llvm/lib/CodeGen/RegAllocGreedy.cpp
+++ b/llvm/lib/CodeGen/RegAllocGreedy.cpp
@@ -2664,7 +2664,7 @@ MCRegister RAGreedy::selectOrSplitImpl(const LiveInterval &VirtReg,
     NamedRegionTimer T("spill", "Spiller", TimerGroupName,
                        TimerGroupDescription, TimePassesIsEnabled);
     LiveRangeEdit LRE(&VirtReg, NewVRegs, *MF, *LIS, VRM, this, &DeadRemats);
-    spiller().spill(LRE);
+    spiller().spill(LRE, &Order);
     ExtraInfo->setStage(NewVRegs.begin(), NewVRegs.end(), RS_Done);
 
     // Tell LiveDebugVariables about the new ranges. Ranges not being covered by
@@ -2908,8 +2908,8 @@ bool RAGreedy::run(MachineFunction &mf) {
   PriorityAdvisor = PriorityProvider->getAdvisor(*MF, *this, *Indexes);
 
   VRAI = std::make_unique<VirtRegAuxInfo>(*MF, *LIS, *VRM, *Loops, *MBFI);
-  SpillerInstance.reset(
-      createInlineSpiller({*LIS, *LSS, *DomTree, *MBFI}, *MF, *VRM, *VRAI));
+  SpillerInstance.reset(createInlineSpiller({*LIS, *LSS, *DomTree, *MBFI}, *MF,
+                                            *VRM, *VRAI, Matrix));
 
   VRAI->calculateSpillWeightsAndHints();