Set an allocation hint when rematting before a COPY.
This almost guarantees that the COPY will be coalesced.
llvm-svn: 125140
diff --git a/llvm/lib/CodeGen/InlineSpiller.cpp b/llvm/lib/CodeGen/InlineSpiller.cpp
index 00ca3d5..a1bd972 100644
--- a/llvm/lib/CodeGen/InlineSpiller.cpp
+++ b/llvm/lib/CodeGen/InlineSpiller.cpp
@@ -154,6 +154,10 @@
LiveInterval &NewLI = edit_->create(mri_, lis_, vrm_);
NewLI.markNotSpillable();
+ // Rematting for a copy: Set allocation hint to be the destination register.
+ if (MI->isCopy())
+ mri_.setRegAllocationHint(NewLI.reg, 0, MI->getOperand(0).getReg());
+
// Finally we can rematerialize OrigMI before MI.
SlotIndex DefIdx = edit_->rematerializeAt(*MI->getParent(), MI, NewLI.reg, RM,
lis_, tii_, tri_);