6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-02 07:11:49 +00:00
Code Issues Projects Releases Wiki Activity

Add some comments.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112437 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2010-08-29 15:27:08 +00:00
parent 3902f9fca8
commit 6a83271532
1 changed files with 13 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
lib/Transforms/Scalar/LoopStrengthReduce.cpp
View File

@ -1932,20 +1932,25 @@ void LSRInstance::DeleteUse(LSRUse &LU) {
LSRUse *
LSRInstance::FindUseWithSimilarFormula(const Formula &OrigF,
const LSRUse &OrigLU) {
// Search all uses for the formula. This could be more clever. Ignore
// ICmpZero uses because they may contain formulae generated by
// GenerateICmpZeroScales, in which case adding fixup offsets may
// be invalid.
// Search all uses for the formula. This could be more clever.
for (size_t LUIdx = 0, NumUses = Uses.size(); LUIdx != NumUses; ++LUIdx) {
LSRUse &LU = Uses[LUIdx];
// Check whether this use is close enough to OrigLU, to see whether it's
// worthwhile looking through its formulae.
// Ignore ICmpZero uses because they may contain formulae generated by
// GenerateICmpZeroScales, in which case adding fixup offsets may
// be invalid.
if (&LU != &OrigLU &&
LU.Kind != LSRUse::ICmpZero &&
LU.Kind == OrigLU.Kind && OrigLU.AccessTy == LU.AccessTy &&
LU.WidestFixupType == OrigLU.WidestFixupType &&
LU.HasFormulaWithSameRegs(OrigF)) {
// Scan through this use's formulae.
for (SmallVectorImpl<Formula>::const_iterator I = LU.Formulae.begin(),
E = LU.Formulae.end(); I != E; ++I) {
const Formula &F = *I;
// Check to see if this formula has the same registers and symbols
// as OrigF.
if (F.BaseRegs == OrigF.BaseRegs &&
F.ScaledReg == OrigF.ScaledReg &&
F.AM.BaseGV == OrigF.AM.BaseGV &&
@ -1953,12 +1958,16 @@ LSRInstance::FindUseWithSimilarFormula(const Formula &OrigF,
LU.Kind) {
if (F.AM.BaseOffs == 0)
return &LU;
// This is the formula where all the registers and symbols matched;
// there aren't going to be any others. Since we declined it, we
// can skip the rest of the formulae and procede to the next LSRUse.
break;
}
}
}
}
// Nothing looked good.
return 0;
}