RPCSX/archived-llvm
1
0
Fork 0
mirror of https://github.com/RPCSX/llvm.git synced 2026-01-31 01:05:23 +01:00
Code Issues Packages Projects Releases Wiki Activity

[LoopUnrollRuntime] NFC: use the precomputed loop exit in ConnectProlog

Browse Source 
Minor refactoring to use the preexisting loop exit that's already
calculated. We do not need to recompute the loop exit in ConnectProlog.
Apart from avoiding redundant computation, this is required for
supporting multiple loop exits when Prolog remainder loops are generated.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307417 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Anna Thomas
2017-07-07 18:05:28 +00:00
parent 9163803bf0
commit 987dd01d1b
1 changed files with 11 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
lib/Transforms/Utils/LoopUnrollRuntime.cpp
View File

@@ -65,9 +65,11 @@ static cl::opt<bool> UnrollRuntimeMultiExit(
/// than the unroll factor.
///
static void ConnectProlog(Loop *L, Value *BECount, unsigned Count,
BasicBlock *PrologExit, BasicBlock *PreHeader,
BasicBlock *NewPreHeader, ValueToValueMapTy &VMap,
DominatorTree *DT, LoopInfo *LI, bool PreserveLCSSA) {
BasicBlock *PrologExit,
BasicBlock *OriginalLoopLatchExit,
BasicBlock *PreHeader, BasicBlock *NewPreHeader,
ValueToValueMapTy &VMap, DominatorTree *DT,
LoopInfo *LI, bool PreserveLCSSA) {
BasicBlock *Latch = L->getLoopLatch();
assert(Latch && "Loop must have a latch");
BasicBlock *PrologLatch = cast<BasicBlock>(VMap[Latch]);
@@ -142,17 +144,15 @@ static void ConnectProlog(Loop *L, Value *BECount, unsigned Count,
// then (BECount + 1) cannot unsigned-overflow.
Value *BrLoopExit =
B.CreateICmpULT(BECount, ConstantInt::get(BECount->getType(), Count - 1));
BasicBlock *Exit = L->getUniqueExitBlock();
assert(Exit && "Loop must have a single exit block only");
// Split the exit to maintain loop canonicalization guarantees
SmallVector<BasicBlock*, 4> Preds(predecessors(Exit));
SplitBlockPredecessors(Exit, Preds, ".unr-lcssa", DT, LI,
SmallVector<BasicBlock *, 4> Preds(predecessors(OriginalLoopLatchExit));
SplitBlockPredecessors(OriginalLoopLatchExit, Preds, ".unr-lcssa", DT, LI,
PreserveLCSSA);
// Add the branch to the exit block (around the unrolled loop)
B.CreateCondBr(BrLoopExit, Exit, NewPreHeader);
B.CreateCondBr(BrLoopExit, OriginalLoopLatchExit, NewPreHeader);
InsertPt->eraseFromParent();
if (DT)
DT->changeImmediateDominator(Exit, PrologExit);
DT->changeImmediateDominator(OriginalLoopLatchExit, PrologExit);
}
/// Connect the unrolling epilog code to the original loop.
@@ -782,8 +782,8 @@ bool llvm::UnrollRuntimeLoopRemainder(Loop *L, unsigned Count,
} else {
// Connect the prolog code to the original loop and update the
// PHI functions.
ConnectProlog(L, BECount, Count, PrologExit, PreHeader, NewPreHeader,
VMap, DT, LI, PreserveLCSSA);
ConnectProlog(L, BECount, Count, PrologExit, LatchExit, PreHeader,
NewPreHeader, VMap, DT, LI, PreserveLCSSA);
}
// If this loop is nested, then the loop unroller changes the code in the