[llvm-commits] [llvm] r60799 - in /llvm/trunk: include/llvm/Analysis/MemoryDependenceAnalysis.h lib/Analysis/MemoryDependenceAnalysis.cpp lib/Transforms/Scalar/GVN.cpp
Chris Lattner
sabre at nondot.org
Tue Dec 9 14:06:24 PST 2008
Author: lattner
Date: Tue Dec 9 16:06:23 2008
New Revision: 60799
URL: http://llvm.org/viewvc/llvm-project?rev=60799&view=rev
Log:
Teach GVN to invalidate some memdep information when it does an RAUW
of a pointer. This allows is to catch more equivalencies. For example,
the type_lists_compatible_p function used to require two iterations of
the gvn pass (!) to delete its 18 redundant loads because the first pass
would CSE all the addressing computation cruft, which would unblock the
second memdep/gvn passes from recognizing them. This change allows
memdep/gvn to catch all 18 when run just once on the function (as is
typical :) instead of just 3.
On all of 403.gcc, this bumps up the # reundandancies found from:
63 gvn - Number of instructions PRE'd
153991 gvn - Number of instructions deleted
50069 gvn - Number of loads deleted
to:
63 gvn - Number of instructions PRE'd
154137 gvn - Number of instructions deleted
50185 gvn - Number of loads deleted
+120 loads deleted isn't bad.
Modified:
llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h
llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp
llvm/trunk/lib/Transforms/Scalar/GVN.cpp
Modified: llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h?rev=60799&r1=60798&r2=60799&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h (original)
+++ llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h Tue Dec 9 16:06:23 2008
@@ -243,6 +243,14 @@
/// updating the dependence of instructions that previously depended on it.
void removeInstruction(Instruction *InstToRemove);
+ /// invalidateCachedPointerInfo - This method is used to invalidate cached
+ /// information about the specified pointer, because it may be too
+ /// conservative in memdep. This is an optional call that can be used when
+ /// the client detects an equivalence between the pointer and some other
+ /// value and replaces the other value with ptr. This can make Ptr available
+ /// in more places that cached info does not necessarily keep.
+ void invalidateCachedPointerInfo(Value *Ptr);
+
private:
MemDepResult getPointerDependencyFrom(Value *Pointer, uint64_t MemSize,
bool isLoad,
@@ -260,7 +268,6 @@
NonLocalDepInfo *Cache,
unsigned NumSortedEntries);
-
void RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P);
/// verifyRemoved - Verify that the specified instruction does not occur
Modified: llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp?rev=60799&r1=60798&r2=60799&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp Tue Dec 9 16:06:23 2008
@@ -698,6 +698,21 @@
}
+/// invalidateCachedPointerInfo - This method is used to invalidate cached
+/// information about the specified pointer, because it may be too
+/// conservative in memdep. This is an optional call that can be used when
+/// the client detects an equivalence between the pointer and some other
+/// value and replaces the other value with ptr. This can make Ptr available
+/// in more places that cached info does not necessarily keep.
+void MemoryDependenceAnalysis::invalidateCachedPointerInfo(Value *Ptr) {
+ // If Ptr isn't really a pointer, just ignore it.
+ if (!isa<PointerType>(Ptr->getType())) return;
+ // Flush store info for the pointer.
+ RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, false));
+ // Flush load info for the pointer.
+ RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, true));
+}
+
/// removeInstruction - Remove an instruction from the dependence analysis,
/// updating the dependence of instructions that previously depended on it.
/// This method attempts to keep the cache coherent using the reverse map.
@@ -864,7 +879,6 @@
AA->deleteValue(RemInst);
DEBUG(verifyRemoved(RemInst));
}
-
/// verifyRemoved - Verify that the specified instruction does not occur
/// in our internal data structures.
void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const {
Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=60799&r1=60798&r2=60799&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Tue Dec 9 16:06:23 2008
@@ -842,6 +842,8 @@
}
PN->replaceAllUsesWith(v);
+ if (isa<PointerType>(v->getType()))
+ MD->invalidateCachedPointerInfo(v);
for (DenseMap<BasicBlock*, Value*>::iterator I = Phis.begin(),
E = Phis.end(); I != E; ++I)
@@ -1015,6 +1017,8 @@
if ((*I)->getParent() == LI->getParent()) {
DEBUG(cerr << "GVN REMOVING NONLOCAL LOAD #1: " << *LI);
LI->replaceAllUsesWith(*I);
+ if (isa<PointerType>((*I)->getType()))
+ MD->invalidateCachedPointerInfo(*I);
toErase.push_back(LI);
NumGVNLoad++;
return true;
@@ -1030,6 +1034,8 @@
// Perform PHI construction.
Value* v = GetValueForBlock(LI->getParent(), LI, BlockReplValues, true);
LI->replaceAllUsesWith(v);
+ if (isa<PointerType>(v->getType()))
+ MD->invalidateCachedPointerInfo(v);
toErase.push_back(LI);
NumGVNLoad++;
return true;
@@ -1124,6 +1130,8 @@
Value* v = GetValueForBlock(LI->getParent(), LI, BlockReplValues, true);
LI->replaceAllUsesWith(v);
v->takeName(LI);
+ if (isa<PointerType>(v->getType()))
+ MD->invalidateCachedPointerInfo(v);
toErase.push_back(LI);
NumPRELoad++;
return true;
@@ -1157,6 +1165,8 @@
// Remove it!
L->replaceAllUsesWith(DepSI->getOperand(0));
+ if (isa<PointerType>(DepSI->getOperand(0)->getType()))
+ MD->invalidateCachedPointerInfo(DepSI->getOperand(0));
toErase.push_back(L);
NumGVNLoad++;
return true;
@@ -1170,6 +1180,8 @@
// Remove it!
L->replaceAllUsesWith(DepLI);
+ if (isa<PointerType>(DepLI->getType()))
+ MD->invalidateCachedPointerInfo(DepLI);
toErase.push_back(L);
NumGVNLoad++;
return true;
@@ -1241,6 +1253,8 @@
PI->second.erase(p);
p->replaceAllUsesWith(constVal);
+ if (isa<PointerType>(constVal->getType()))
+ MD->invalidateCachedPointerInfo(constVal);
toErase.push_back(p);
} else {
localAvail[I->getParent()]->table.insert(std::make_pair(num, I));
@@ -1257,6 +1271,8 @@
// Remove it!
VN.erase(I);
I->replaceAllUsesWith(repl);
+ if (isa<PointerType>(repl->getType()))
+ MD->invalidateCachedPointerInfo(repl);
toErase.push_back(I);
return true;
} else {
@@ -1494,6 +1510,8 @@
localAvail[CurrentBlock]->table[valno] = Phi;
CurInst->replaceAllUsesWith(Phi);
+ if (isa<PointerType>(Phi->getType()))
+ MD->invalidateCachedPointerInfo(Phi);
VN.erase(CurInst);
DEBUG(cerr << "GVN PRE removed: " << *CurInst);
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