optimize FastISel::UpdateValueMap to avoid duplicate map lookups,
and make it return the assigned register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68888 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 8467330..7e30053 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -149,16 +149,21 @@
/// NOTE: This is only necessary because we might select a block that uses
/// a value before we select the block that defines the value. It might be
/// possible to fix this by selecting blocks in reverse postorder.
-void FastISel::UpdateValueMap(Value* I, unsigned Reg) {
+unsigned FastISel::UpdateValueMap(Value* I, unsigned Reg) {
if (!isa<Instruction>(I)) {
LocalValueMap[I] = Reg;
- return;
+ return Reg;
}
- if (!ValueMap.count(I))
- ValueMap[I] = Reg;
- else
- TII.copyRegToReg(*MBB, MBB->end(), ValueMap[I],
- Reg, MRI.getRegClass(Reg), MRI.getRegClass(Reg));
+
+ unsigned &AssignedReg = ValueMap[I];
+ if (AssignedReg == 0)
+ AssignedReg = Reg;
+ else {
+ const TargetRegisterClass *RegClass = MRI.getRegClass(Reg);
+ TII.copyRegToReg(*MBB, MBB->end(), AssignedReg,
+ Reg, RegClass, RegClass);
+ }
+ return AssignedReg;
}
unsigned FastISel::getRegForGEPIndex(Value *Idx) {