From df359c264eb717ea69ca8dbda91992d707928af0 Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Wed, 8 Aug 2007 17:58:56 +0000 Subject: [PATCH] Small improvement: if a function doesn't access memory, we don't need to scan it for potentially undeading pointers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40933 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/DeadStoreElimination.cpp | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp index 39a0aba2c95..bcf674ed37f 100644 --- a/lib/Transforms/Scalar/DeadStoreElimination.cpp +++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp @@ -287,6 +287,13 @@ bool DSE::handleEndBlock(BasicBlock& BB, deadPointers.erase(A); continue; } else if (CallSite::get(BBI).getInstruction() != 0) { + // If this call does not access memory, it can't + // be undeadifying any of our pointers. + CallSite CS = CallSite::get(BBI); + if (CS.getCalledFunction() && + AA.doesNotAccessMemory(CS.getCalledFunction())) + continue; + // Remove any pointers made undead by the call from the dead set std::vector dead; for (SmallPtrSet::iterator I = deadPointers.begin(), @@ -298,8 +305,7 @@ bool DSE::handleEndBlock(BasicBlock& BB, TD.getTypeSize((*I)->getAllocatedType()); // See if the call site touches it - AliasAnalysis::ModRefResult A = AA.getModRefInfo(CallSite::get(BBI), - *I, pointerSize); + AliasAnalysis::ModRefResult A = AA.getModRefInfo(CS, *I, pointerSize); if (A == AliasAnalysis::ModRef || A == AliasAnalysis::Ref) dead.push_back(*I); }