RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2025-03-03 16:18:37 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[SCEV][NFC] Share value cache between SCEVs in GroupByComplexity

Browse Source 
Current implementation of `compareSCEVComplexity` is being unreasonable with `SCEVUnknown`s:
every time it sees one, it creates a new value cache and tries to prove equality of two values using it.
This cache reallocates and gets lost from SCEV to SCEV.

This patch changes this behavior: now we create one cache for all values and share it between SCEVs.

Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D40597


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319880 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Max Kazantsev 2017-12-06 08:58:16 +00:00
parent 4fe5c0ae02
commit 3126a95a41
1 changed files with 26 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
lib/Analysis/ScalarEvolution.cpp
View File

@ -549,10 +549,10 @@ bool SCEVUnknown::isOffsetOf(Type *&CTy, Constant *&FieldNo) const {
/// Since we do not continue running this routine on expression trees once we
/// have seen unequal values, there is no need to track them in the cache.
static int
CompareValueComplexity(EquivalenceClasses<Value *> &EqCache,
CompareValueComplexity(EquivalenceClasses<const Value *> &EqCacheValue,
const LoopInfo *const LI, Value *LV, Value *RV,
unsigned Depth) {
if (Depth > MaxValueCompareDepth || EqCache.isEquivalent(LV, RV))
if (Depth > MaxValueCompareDepth || EqCacheValue.isEquivalent(LV, RV))
return 0;
// Order pointer values after integer values. This helps SCEVExpander form
@ -612,14 +612,14 @@ CompareValueComplexity(EquivalenceClasses<Value *> &EqCache,
for (unsigned Idx : seq(0u, LNumOps)) {
int Result =
CompareValueComplexity(EqCache, LI, LInst->getOperand(Idx),
CompareValueComplexity(EqCacheValue, LI, LInst->getOperand(Idx),
RInst->getOperand(Idx), Depth + 1);
if (Result != 0)
return Result;
}
}
EqCache.unionSets(LV, RV);
EqCacheValue.unionSets(LV, RV);
return 0;
}
@ -628,6 +628,7 @@ CompareValueComplexity(EquivalenceClasses<Value *> &EqCache,
// more efficient.
static int CompareSCEVComplexity(
EquivalenceClasses<const SCEV *> &EqCacheSCEV,
EquivalenceClasses<const Value *> &EqCacheValue,
const LoopInfo *const LI, const SCEV *LHS, const SCEV *RHS,
DominatorTree &DT, unsigned Depth = 0) {
// Fast-path: SCEVs are uniqued so we can do a quick equality check.
@ -649,9 +650,8 @@ static int CompareSCEVComplexity(
const SCEVUnknown *LU = cast<SCEVUnknown>(LHS);
const SCEVUnknown *RU = cast<SCEVUnknown>(RHS);
EquivalenceClasses<Value *> EqCache;
int X = CompareValueComplexity(EqCache, LI, LU->getValue(), RU->getValue(),
Depth + 1);
int X = CompareValueComplexity(EqCacheValue, LI, LU->getValue(),
RU->getValue(), Depth + 1);
if (X == 0)
EqCacheSCEV.unionSets(LHS, RHS);
return X;
@ -696,8 +696,9 @@ static int CompareSCEVComplexity(
// Lexicographically compare.
for (unsigned i = 0; i != LNumOps; ++i) {
int X = CompareSCEVComplexity(EqCacheSCEV, LI, LA->getOperand(i),
RA->getOperand(i), DT, Depth + 1);
int X = CompareSCEVComplexity(EqCacheSCEV, EqCacheValue, LI,
LA->getOperand(i), RA->getOperand(i), DT,
Depth + 1);
if (X != 0)
return X;
}
@ -718,8 +719,9 @@ static int CompareSCEVComplexity(
return (int)LNumOps - (int)RNumOps;
for (unsigned i = 0; i != LNumOps; ++i) {
int X = CompareSCEVComplexity(EqCacheSCEV, LI, LC->getOperand(i),
RC->getOperand(i), DT, Depth + 1);
int X = CompareSCEVComplexity(EqCacheSCEV, EqCacheValue, LI,
LC->getOperand(i), RC->getOperand(i), DT,
Depth + 1);
if (X != 0)
return X;
}
@ -732,12 +734,12 @@ static int CompareSCEVComplexity(
const SCEVUDivExpr *RC = cast<SCEVUDivExpr>(RHS);
// Lexicographically compare udiv expressions.
int X = CompareSCEVComplexity(EqCacheSCEV, LI, LC->getLHS(), RC->getLHS(),
DT, Depth + 1);
int X = CompareSCEVComplexity(EqCacheSCEV, EqCacheValue, LI, LC->getLHS(),
RC->getLHS(), DT, Depth + 1);
if (X != 0)
return X;
X = CompareSCEVComplexity(EqCacheSCEV, LI, LC->getRHS(), RC->getRHS(), DT,
Depth + 1);
X = CompareSCEVComplexity(EqCacheSCEV, EqCacheValue, LI, LC->getRHS(),
RC->getRHS(), DT, Depth + 1);
if (X == 0)
EqCacheSCEV.unionSets(LHS, RHS);
return X;
@ -750,8 +752,9 @@ static int CompareSCEVComplexity(
const SCEVCastExpr *RC = cast<SCEVCastExpr>(RHS);
// Compare cast expressions by operand.
int X = CompareSCEVComplexity(EqCacheSCEV, LI, LC->getOperand(),
RC->getOperand(), DT, Depth + 1);
int X = CompareSCEVComplexity(EqCacheSCEV, EqCacheValue, LI,
LC->getOperand(), RC->getOperand(), DT,
Depth + 1);
if (X == 0)
EqCacheSCEV.unionSets(LHS, RHS);
return X;
@ -776,21 +779,22 @@ static void GroupByComplexity(SmallVectorImpl<const SCEV *> &Ops,
LoopInfo *LI, DominatorTree &DT) {
if (Ops.size() < 2) return; // Noop
EquivalenceClasses<const SCEV *> EqCache;
EquivalenceClasses<const SCEV *> EqCacheSCEV;
EquivalenceClasses<const Value *> EqCacheValue;
if (Ops.size() == 2) {
// This is the common case, which also happens to be trivially simple.
// Special case it.
const SCEV *&LHS = Ops[0], *&RHS = Ops[1];
if (CompareSCEVComplexity(EqCache, LI, RHS, LHS, DT) < 0)
if (CompareSCEVComplexity(EqCacheSCEV, EqCacheValue, LI, RHS, LHS, DT) < 0)
std::swap(LHS, RHS);
return;
}
// Do the rough sort by complexity.
std::stable_sort(Ops.begin(), Ops.end(),
[&EqCache, LI, &DT](const SCEV *LHS, const SCEV *RHS) {
return
CompareSCEVComplexity(EqCache, LI, LHS, RHS, DT) < 0;
[&](const SCEV *LHS, const SCEV *RHS) {
return CompareSCEVComplexity(EqCacheSCEV, EqCacheValue, LI,
LHS, RHS, DT) < 0;
});
// Now that we are sorted by complexity, group elements of the same