Fix up comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53586 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nick Lewycky 2008-07-15 03:40:27 +00:00
parent b27cb55923
commit 86dae65baa

View File

@ -2675,7 +2675,7 @@ bool ScalarEvolutionsImpl::executesAtLeastOnce(const Loop *L, bool isSigned,
return false;
}
if (!PreCondLHS->getType()->isInteger()) return false;
if (PreCondLHS->getType()->isInteger()) return false;
return LHS == getSCEV(PreCondLHS) && RHS == getSCEV(PreCondRHS);
}
@ -2706,12 +2706,14 @@ HowManyLessThans(SCEV *LHS, SCEV *RHS, const Loop *L, bool isSigned) {
// First, we get the value of the LHS in the first iteration: n
SCEVHandle Start = AddRec->getOperand(0);
// Then, we get the value of the LHS in the first iteration in which the
// above condition doesn't hold. This equals to max(m,n).
if (executesAtLeastOnce(L, isSigned,
SE.getMinusSCEV(AddRec->getOperand(0), One), RHS))
SE.getMinusSCEV(AddRec->getOperand(0), One), RHS)) {
// Since we know that the condition is true in order to enter the loop,
// we know that it will run exactly m-n times.
return SE.getMinusSCEV(RHS, Start);
else {
} else {
// Then, we get the value of the LHS in the first iteration in which the
// above condition doesn't hold. This equals to max(m,n).
SCEVHandle End = isSigned ? SE.getSMaxExpr(RHS, Start)
: SE.getUMaxExpr(RHS, Start);