maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

ADd a trivial instcombine: load null -> null 

llvm-svn: 12940
This commit is contained in:
Chris Lattner 2004-04-14 03:28:36 +00:00
parent 0dc099c2b5
commit 6679e46b59
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
View File

@ -2853,8 +2853,11 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
Value *Op = LI.getOperand(0); Value *Op = LI.getOperand(0);
if (LI.isVolatile()) return 0; if (LI.isVolatile()) return 0;
if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(Op)) if (Constant *C = dyn_cast<Constant>(Op))
Op = CPR->getValue(); if (C->isNullValue()) // load null -> 0
return ReplaceInstUsesWith(LI, Constant::getNullValue(LI.getType()));
else if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(C))
Op = CPR->getValue();
// Instcombine load (constant global) into the value loaded... // Instcombine load (constant global) into the value loaded...
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op)) if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op))