diff options
Diffstat (limited to 'lib/Transforms/Utils/Local.cpp')
| -rw-r--r-- | lib/Transforms/Utils/Local.cpp | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index be0aa82500..7034feb227 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -721,10 +721,14 @@ bool llvm::EliminateDuplicatePHINodes(BasicBlock *BB) { /// their preferred alignment from the beginning. /// static unsigned enforceKnownAlignment(Value *V, unsigned Align, - unsigned PrefAlign) { + unsigned PrefAlign, const TargetData *TD) { V = V->stripPointerCasts(); if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) { + // If the preferred alignment is greater than the natural stack alignment + // then don't round up. This avoids dynamic stack realignment. + if (TD && TD->exceedsNaturalStackAlignment(PrefAlign)) + return Align; // If there is a requested alignment and if this is an alloca, round up. if (AI->getAlignment() >= PrefAlign) return AI->getAlignment(); @@ -775,7 +779,7 @@ unsigned llvm::getOrEnforceKnownAlignment(Value *V, unsigned PrefAlign, Align = std::min(Align, +Value::MaximumAlignment); if (PrefAlign > Align) - Align = enforceKnownAlignment(V, Align, PrefAlign); + Align = enforceKnownAlignment(V, Align, PrefAlign, TD); // We don't need to make any adjustment. return Align; |