6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-15 04:30:12 +00:00
Code Issues Projects Releases Wiki Activity

Implement a trivial form of store->load forwarding where the store and the

Browse Source 
load are exactly consequtive.  This is picked up by other passes, but this
triggers thousands of times in fortran programs that use static locals
(and is thus a compile-time speedup).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23320 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-09-12 22:00:15 +00:00
parent 598fbf756f
commit 62f254df04
1 changed files with 9 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
lib/Transforms/Scalar/InstructionCombining.cpp
View File

@ -4925,6 +4925,15 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
// None of the following transforms are legal for volatile loads.
if (LI.isVolatile()) return 0;
// If the instruction immediately before this is a store to the same address,
// do a simple form of store->load forwarding.
if (&LI.getParent()->front() != &LI) {
BasicBlock::iterator BBI = &LI; --BBI;
if (StoreInst *SI = dyn_cast<StoreInst>(BBI))
if (SI->getOperand(1) == LI.getOperand(0))
return ReplaceInstUsesWith(LI, SI->getOperand(0));
}
if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(Op))
if (isa<ConstantPointerNull>(GEPI->getOperand(0)) ||