Trivially re-materializable instructions have spill weights that are half of what it would be otherwise.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35658 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index a01889a..3858a98 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -164,13 +164,13 @@
unsigned reg = rep(mop.getReg());
mii->getOperand(i).setReg(reg);
- // If the definition instruction is re-materializable, its spill
- // weight is zero.
LiveInterval &RegInt = getInterval(reg);
- if (!RegInt.remat) {
- RegInt.weight +=
- (mop.isUse() + mop.isDef()) * pow(10.0F, (int)loopDepth);
- }
+ float w = (mop.isUse()+mop.isDef()) * powf(10.0F, (float)loopDepth);
+ // If the definition instruction is re-materializable, its spill
+ // weight is half of what it would have been normally.
+ if (RegInt.remat)
+ w /= 2;
+ RegInt.weight += w;
}
}
++mii;