We were default constructing the Lower/Upper APInts. Then creating min or max value, then doing a move assignment to Lower and copy assignment to upper. The copy assignment operator in particular has an out of line function call that has to examine whether or not a previous allocation exists that can be reused which of course it can't in this case.
The new code creates the min/max value first, move constructs Lower from it then copy constructs Upper from Lower.
This also seems to have convinced a self host build that this constructor can be inlined more readily into other methods in ConstantRange.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301736
91177308-0d34-0410-b5e6-
96231b3b80d8
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
-ConstantRange::ConstantRange(uint32_t BitWidth, bool Full) {
- if (Full)
- Lower = Upper = APInt::getMaxValue(BitWidth);
- else
- Lower = Upper = APInt::getMinValue(BitWidth);
-}
+ConstantRange::ConstantRange(uint32_t BitWidth, bool Full)
+ : Lower(Full ? APInt::getMaxValue(BitWidth) : APInt::getMinValue(BitWidth)),
+ Upper(Lower) {}
ConstantRange::ConstantRange(APInt V)
: Lower(std::move(V)), Upper(Lower + 1) {}