6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-07-25 13:24:46 +00:00
Code Issues Projects Releases Wiki Activity

Atomic load/store support in LICM.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137648 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Friedman
2011-08-15 20:52:09 +00:00
parent c537f3be0c
commit 97671565ff
3 changed files with 97 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
lib/Transforms/Scalar/LICM.cpp
View File

@@ -362,8 +362,8 @@ void LICM::HoistRegion(DomTreeNode *N) {
bool LICM::canSinkOrHoistInst(Instruction &I) {
// Loads have extra constraints we have to verify before we can hoist them.
if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
if (LI->isVolatile())
return false; // Don't hoist volatile loads!
if (!LI->isUnordered())
return false; // Don't hoist volatile/atomic loads!
// Loads from constant memory are always safe to move, even if they end up
// in the same alias set as something that ends up being modified.
@@ -722,15 +722,18 @@ void LICM::PromoteAliasSet(AliasSet &AS) {
// If there is an non-load/store instruction in the loop, we can't promote
// it.
if (isa<LoadInst>(Use)) {
assert(!cast<LoadInst>(Use)->isVolatile() && "AST broken");
if (LoadInst *load = dyn_cast<LoadInst>(Use)) {
assert(!load->isVolatile() && "AST broken");
if (!load->isSimple())
return;
} else if (StoreInst *store = dyn_cast<StoreInst>(Use)) {
// Stores *of* the pointer are not interesting, only stores *to* the
// pointer.
if (Use->getOperand(1) != ASIV)
continue;
unsigned InstAlignment = store->getAlignment();
assert(!cast<StoreInst>(Use)->isVolatile() && "AST broken");
assert(!store->isVolatile() && "AST broken");
if (!store->isSimple())
return;
// Note that we only check GuaranteedToExecute inside the store case
// so that we do not introduce stores where they did not exist before
@@ -740,6 +743,7 @@ void LICM::PromoteAliasSet(AliasSet &AS) {
// restrictive (and performant) alignment and if we are sure this
// instruction will be executed, update the alignment.
// Larger is better, with the exception of 0 being the best alignment.
unsigned InstAlignment = store->getAlignment();
if ((InstAlignment > Alignment || InstAlignment == 0)
&& (Alignment != 0))
if (isGuaranteedToExecute(*Use)) {