maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[SCEV] Remove extra APInt copies from getRangeForAffineARHelper. 

This changes one parameter to be a const APInt& since we only read from it. Use std::move on local APInts once they are no longer needed so we can reuse their allocations. Lastly, use operator+=(uint64_t) instead of adding 1 to an APInt twice creating a new APInt each time.

llvm-svn: 302335
This commit is contained in:
Craig Topper 2017-05-06 06:03:07 +00:00
parent 69f1af29fb
commit 6c5e22a4b8
1 changed files with 10 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
llvm/lib/Analysis/ScalarEvolution.cpp
View File

@ -4843,7 +4843,7 @@ ScalarEvolution::getRange(const SCEV *S,
// argument defines if we treat Step as signed or unsigned.
static ConstantRange getRangeForAffineARHelper(APInt Step,
ConstantRange StartRange,
APInt MaxBECount,
const APInt &MaxBECount,
unsigned BitWidth, bool Signed) {
// If either Step or MaxBECount is 0, then the expression won't change, and we
// just need to return the initial range.
@ -4882,8 +4882,8 @@ static ConstantRange getRangeForAffineARHelper(APInt Step,
// if the expression is decreasing and will be increased by Offset otherwise.
APInt StartLower = StartRange.getLower();
APInt StartUpper = StartRange.getUpper() - 1;
APInt MovedBoundary =
Descending ? (StartLower - Offset) : (StartUpper + Offset);
APInt MovedBoundary = Descending ? (StartLower - std::move(Offset))
: (StartUpper + std::move(Offset));
// It's possible that the new minimum/maximum value will fall into the initial
// range (due to wrap around). This means that the expression can take any
@ -4891,21 +4891,18 @@ static ConstantRange getRangeForAffineARHelper(APInt Step,
if (StartRange.contains(MovedBoundary))
return ConstantRange(BitWidth, /* isFullSet = */ true);
APInt NewLower, NewUpper;
if (Descending) {
NewLower = MovedBoundary;
NewUpper = StartUpper;
} else {
NewLower = StartLower;
NewUpper = MovedBoundary;
}
APInt NewLower =
Descending ? std::move(MovedBoundary) : std::move(StartLower);
APInt NewUpper =
Descending ? std::move(StartUpper) : std::move(MovedBoundary);
NewUpper += 1;
// If we end up with full range, return a proper full range.
if (NewLower == NewUpper + 1)
if (NewLower == NewUpper)
return ConstantRange(BitWidth, /* isFullSet = */ true);
// No overflow detected, return [StartLower, StartUpper + Offset + 1) range.
return ConstantRange(NewLower, NewUpper + 1);
return ConstantRange(std::move(NewLower), std::move(NewUpper));
}
ConstantRange ScalarEvolution::getRangeForAffineAR(const SCEV *Start,