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-rw-r--r--lib/Transforms/Scalar/GVN.cpp72
1 files changed, 34 insertions, 38 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 106eba0..7dba4e2 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -24,6 +24,7 @@
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/AssumptionTracker.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
@@ -45,6 +46,7 @@
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/SSAUpdater.h"
#include <vector>
using namespace llvm;
@@ -590,6 +592,7 @@ namespace {
DominatorTree *DT;
const DataLayout *DL;
const TargetLibraryInfo *TLI;
+ AssumptionTracker *AT;
SetVector<BasicBlock *> DeadBlocks;
ValueTable VN;
@@ -679,6 +682,7 @@ namespace {
// This transformation requires dominator postdominator info
void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addRequired<AssumptionTracker>();
AU.addRequired<DominatorTreeWrapperPass>();
AU.addRequired<TargetLibraryInfo>();
if (!NoLoads)
@@ -727,6 +731,7 @@ FunctionPass *llvm::createGVNPass(bool NoLoads) {
}
INITIALIZE_PASS_BEGIN(GVN, "gvn", "Global Value Numbering", false, false)
+INITIALIZE_PASS_DEPENDENCY(AssumptionTracker)
INITIALIZE_PASS_DEPENDENCY(MemoryDependenceAnalysis)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
@@ -1616,7 +1621,7 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
// If all preds have a single successor, then we know it is safe to insert
// the load on the pred (?!?), so we can insert code to materialize the
// pointer if it is not available.
- PHITransAddr Address(LI->getPointerOperand(), DL);
+ PHITransAddr Address(LI->getPointerOperand(), DL, AT);
Value *LoadPtr = nullptr;
LoadPtr = Address.PHITranslateWithInsertion(LoadBB, UnavailablePred,
*DT, NewInsts);
@@ -1669,9 +1674,11 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
LI->getAlignment(),
UnavailablePred->getTerminator());
- // Transfer the old load's TBAA tag to the new load.
- if (MDNode *Tag = LI->getMetadata(LLVMContext::MD_tbaa))
- NewLoad->setMetadata(LLVMContext::MD_tbaa, Tag);
+ // Transfer the old load's AA tags to the new load.
+ AAMDNodes Tags;
+ LI->getAAMetadata(Tags);
+ if (Tags)
+ NewLoad->setAAMetadata(Tags);
// Transfer DebugLoc.
NewLoad->setDebugLoc(LI->getDebugLoc());
@@ -1774,36 +1781,24 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) {
ReplOp->setHasNoUnsignedWrap(false);
}
if (Instruction *ReplInst = dyn_cast<Instruction>(Repl)) {
- SmallVector<std::pair<unsigned, MDNode*>, 4> Metadata;
- ReplInst->getAllMetadataOtherThanDebugLoc(Metadata);
- for (int i = 0, n = Metadata.size(); i < n; ++i) {
- unsigned Kind = Metadata[i].first;
- MDNode *IMD = I->getMetadata(Kind);
- MDNode *ReplMD = Metadata[i].second;
- switch(Kind) {
- default:
- ReplInst->setMetadata(Kind, nullptr); // Remove unknown metadata
- break;
- case LLVMContext::MD_dbg:
- llvm_unreachable("getAllMetadataOtherThanDebugLoc returned a MD_dbg");
- case LLVMContext::MD_tbaa:
- ReplInst->setMetadata(Kind, MDNode::getMostGenericTBAA(IMD, ReplMD));
- break;
- case LLVMContext::MD_range:
- ReplInst->setMetadata(Kind, MDNode::getMostGenericRange(IMD, ReplMD));
- break;
- case LLVMContext::MD_prof:
- llvm_unreachable("MD_prof in a non-terminator instruction");
- break;
- case LLVMContext::MD_fpmath:
- ReplInst->setMetadata(Kind, MDNode::getMostGenericFPMath(IMD, ReplMD));
- break;
- case LLVMContext::MD_invariant_load:
- // Only set the !invariant.load if it is present in both instructions.
- ReplInst->setMetadata(Kind, IMD);
- break;
- }
- }
+ // FIXME: If both the original and replacement value are part of the
+ // same control-flow region (meaning that the execution of one
+ // guarentees the executation of the other), then we can combine the
+ // noalias scopes here and do better than the general conservative
+ // answer used in combineMetadata().
+
+ // In general, GVN unifies expressions over different control-flow
+ // regions, and so we need a conservative combination of the noalias
+ // scopes.
+ unsigned KnownIDs[] = {
+ LLVMContext::MD_tbaa,
+ LLVMContext::MD_alias_scope,
+ LLVMContext::MD_noalias,
+ LLVMContext::MD_range,
+ LLVMContext::MD_fpmath,
+ LLVMContext::MD_invariant_load,
+ };
+ combineMetadata(ReplInst, I, KnownIDs);
}
}
@@ -2219,7 +2214,7 @@ bool GVN::processInstruction(Instruction *I) {
// to value numbering it. Value numbering often exposes redundancies, for
// example if it determines that %y is equal to %x then the instruction
// "%z = and i32 %x, %y" becomes "%z = and i32 %x, %x" which we now simplify.
- if (Value *V = SimplifyInstruction(I, DL, TLI, DT)) {
+ if (Value *V = SimplifyInstruction(I, DL, TLI, DT, AT)) {
I->replaceAllUsesWith(V);
if (MD && V->getType()->getScalarType()->isPointerTy())
MD->invalidateCachedPointerInfo(V);
@@ -2339,6 +2334,7 @@ bool GVN::runOnFunction(Function& F) {
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
DL = DLP ? &DLP->getDataLayout() : nullptr;
+ AT = &getAnalysis<AssumptionTracker>();
TLI = &getAnalysis<TargetLibraryInfo>();
VN.setAliasAnalysis(&getAnalysis<AliasAnalysis>());
VN.setMemDep(MD);
@@ -2653,8 +2649,8 @@ bool GVN::iterateOnFunction(Function &F) {
//
std::vector<BasicBlock *> BBVect;
BBVect.reserve(256);
- for (DomTreeNode *x : depth_first(DT->getRootNode()))
- BBVect.push_back(x->getBlock());
+ for (DomTreeNode *X : depth_first(DT->getRootNode()))
+ BBVect.push_back(X->getBlock());
for (std::vector<BasicBlock *>::iterator I = BBVect.begin(), E = BBVect.end();
I != E; I++)
@@ -2802,7 +2798,7 @@ bool GVN::processFoldableCondBr(BranchInst *BI) {
return true;
}
-// performPRE() will trigger assert if it come across an instruciton without
+// performPRE() will trigger assert if it comes across an instruction without
// associated val-num. As it normally has far more live instructions than dead
// instructions, it makes more sense just to "fabricate" a val-number for the
// dead code than checking if instruction involved is dead or not.
generated by cgit v1.1 at 2024-12-22 18:21:56 +0000