[NFC] Simplify code & reduce nest slightly
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353832 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index fcf6a2b..cca425b 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -8103,44 +8103,46 @@
// exit value from the loop without using SCEVs.
if (const SCEVUnknown *SU = dyn_cast<SCEVUnknown>(V)) {
if (Instruction *I = dyn_cast<Instruction>(SU->getValue())) {
- const Loop *LI = this->LI[I->getParent()];
- if (LI && LI->getParentLoop() == L) // Looking for loop exit value.
- if (PHINode *PN = dyn_cast<PHINode>(I))
- if (PN->getParent() == LI->getHeader()) {
- // Okay, there is no closed form solution for the PHI node. Check
- // to see if the loop that contains it has a known backedge-taken
- // count. If so, we may be able to force computation of the exit
- // value.
- const SCEV *BackedgeTakenCount = getBackedgeTakenCount(LI);
- if (const SCEVConstant *BTCC =
- dyn_cast<SCEVConstant>(BackedgeTakenCount)) {
+ if (PHINode *PN = dyn_cast<PHINode>(I)) {
+ const Loop *LI = this->LI[I->getParent()];
+ // Looking for loop exit value.
+ if (LI && LI->getParentLoop() == L &&
+ PN->getParent() == LI->getHeader()) {
+ // Okay, there is no closed form solution for the PHI node. Check
+ // to see if the loop that contains it has a known backedge-taken
+ // count. If so, we may be able to force computation of the exit
+ // value.
+ const SCEV *BackedgeTakenCount = getBackedgeTakenCount(LI);
+ if (const SCEVConstant *BTCC =
+ dyn_cast<SCEVConstant>(BackedgeTakenCount)) {
- // This trivial case can show up in some degenerate cases where
- // the incoming IR has not yet been fully simplified.
- if (BTCC->getValue()->isZero()) {
- Value *InitValue = nullptr;
- bool MultipleInitValues = false;
- for (unsigned i = 0; i < PN->getNumIncomingValues(); i++) {
- if (!LI->contains(PN->getIncomingBlock(i))) {
- if (!InitValue)
- InitValue = PN->getIncomingValue(i);
- else if (InitValue != PN->getIncomingValue(i)) {
- MultipleInitValues = true;
- break;
- }
+ // This trivial case can show up in some degenerate cases where
+ // the incoming IR has not yet been fully simplified.
+ if (BTCC->getValue()->isZero()) {
+ Value *InitValue = nullptr;
+ bool MultipleInitValues = false;
+ for (unsigned i = 0; i < PN->getNumIncomingValues(); i++) {
+ if (!LI->contains(PN->getIncomingBlock(i))) {
+ if (!InitValue)
+ InitValue = PN->getIncomingValue(i);
+ else if (InitValue != PN->getIncomingValue(i)) {
+ MultipleInitValues = true;
+ break;
}
- if (!MultipleInitValues && InitValue)
- return getSCEV(InitValue);
}
+ if (!MultipleInitValues && InitValue)
+ return getSCEV(InitValue);
}
- // Okay, we know how many times the containing loop executes. If
- // this is a constant evolving PHI node, get the final value at
- // the specified iteration number.
- Constant *RV =
- getConstantEvolutionLoopExitValue(PN, BTCC->getAPInt(), LI);
- if (RV) return getSCEV(RV);
}
+ // Okay, we know how many times the containing loop executes. If
+ // this is a constant evolving PHI node, get the final value at
+ // the specified iteration number.
+ Constant *RV =
+ getConstantEvolutionLoopExitValue(PN, BTCC->getAPInt(), LI);
+ if (RV) return getSCEV(RV);
}
+ }
+ }
// Okay, this is an expression that we cannot symbolically evaluate
// into a SCEV. Check to see if it's possible to symbolically evaluate
