From c5c03f90240e1d2bf9f1579ae14b5dc8f0547c33 Mon Sep 17 00:00:00 2001 From: Jin-Gu Kang Date: Sat, 12 Mar 2011 12:18:44 +0000 Subject: This patch removes some of useless instructions generated by bitfield access. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127539 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../InstCombine/InstCombineLoadStoreAlloca.cpp | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index 35c1d91d50..f233ca6af1 100644 --- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -429,9 +429,19 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { // the pointer we're loading and is producing the pointer we're storing, // then *this* store is dead (X = load P; store X -> P). if (LoadInst *LI = dyn_cast(BBI)) { - if (LI == Val && equivalentAddressValues(LI->getOperand(0), Ptr) && - !SI.isVolatile()) - return EraseInstFromFunction(SI); + if (equivalentAddressValues(LI->getOperand(0), Ptr) && + !SI.isVolatile()) { + if (LI == Val) + return EraseInstFromFunction(SI); + if (Ptr->hasNUses(2)) { + if (GetElementPtrInst *GEP = dyn_cast(Ptr)) { + if (isa(GEP->getOperand(0))) { + if (GEP->getOperand(0)->hasOneUse()) + return EraseInstFromFunction(SI); + } + } + } + } // Otherwise, this is a load from some other location. Stores before it // may not be dead. -- cgit v1.2.3