[llvm] r291405 - [MemDep] NFC walk invariant.group graph only down
Piotr Padlewski via llvm-commits
llvm-commits at lists.llvm.org
Sun Jan 8 14:26:06 PST 2017
Author: prazek
Date: Sun Jan 8 16:26:06 2017
New Revision: 291405
URL: http://llvm.org/viewvc/llvm-project?rev=291405&view=rev
Log:
[MemDep] NFC walk invariant.group graph only down
Summary:
By using stripPointerCasts we can get to the root
value and then walk down the bitcast graph
Reviewers: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28181
Modified:
llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp
llvm/trunk/test/Transforms/GVN/invariant.group.ll
llvm/trunk/test/Transforms/NewGVN/invariant.group.ll
Modified: llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp?rev=291405&r1=291404&r2=291405&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp Sun Jan 8 16:26:06 2017
@@ -344,38 +344,24 @@ MemoryDependenceResults::getInvariantGro
if (!InvariantGroupMD)
return MemDepResult::getUnknown();
- Value *LoadOperand = LI->getPointerOperand();
+ // Take the ptr operand after all casts and geps 0. This way we can search
+ // cast graph down only.
+ Value *LoadOperand = LI->getPointerOperand()->stripPointerCasts();
+
// It's is not safe to walk the use list of global value, because function
// passes aren't allowed to look outside their functions.
+ // FIXME: this could be fixed by filtering instructions from outside
+ // of current function.
if (isa<GlobalValue>(LoadOperand))
return MemDepResult::getUnknown();
// Queue to process all pointers that are equivalent to load operand.
SmallVector<const Value *, 8> LoadOperandsQueue;
- SmallSet<const Value *, 14> SeenValues;
- auto TryInsertToQueue = [&](Value *V) {
- if (SeenValues.insert(V).second)
- LoadOperandsQueue.push_back(V);
- };
-
- TryInsertToQueue(LoadOperand);
+ LoadOperandsQueue.push_back(LoadOperand);
while (!LoadOperandsQueue.empty()) {
const Value *Ptr = LoadOperandsQueue.pop_back_val();
- assert(Ptr);
- if (isa<GlobalValue>(Ptr))
- continue;
-
- // Value comes from bitcast: Ptr = bitcast x. Insert x.
- if (auto *BCI = dyn_cast<BitCastInst>(Ptr))
- TryInsertToQueue(BCI->getOperand(0));
- // Gep with zeros is equivalent to bitcast.
- // FIXME: we are not sure if some bitcast should be canonicalized to gep 0
- // or gep 0 to bitcast because of SROA, so there are 2 forms. When typeless
- // pointers will be upstream then both cases will be gone (and this BFS
- // also won't be needed).
- if (auto *GEP = dyn_cast<GetElementPtrInst>(Ptr))
- if (GEP->hasAllZeroIndices())
- TryInsertToQueue(GEP->getOperand(0));
+ assert(Ptr && !isa<GlobalValue>(Ptr) &&
+ "Null or GlobalValue should not be inserted");
for (const Use &Us : Ptr->uses()) {
auto *U = dyn_cast<Instruction>(Us.getUser());
@@ -385,13 +371,17 @@ MemoryDependenceResults::getInvariantGro
// Bitcast or gep with zeros are using Ptr. Add to queue to check it's
// users. U = bitcast Ptr
if (isa<BitCastInst>(U)) {
- TryInsertToQueue(U);
+ LoadOperandsQueue.push_back(U);
continue;
}
- // U = getelementptr Ptr, 0, 0...
+ // Gep with zeros is equivalent to bitcast.
+ // FIXME: we are not sure if some bitcast should be canonicalized to gep 0
+ // or gep 0 to bitcast because of SROA, so there are 2 forms. When
+ // typeless pointers will be ready then both cases will be gone
+ // (and this BFS also won't be needed).
if (auto *GEP = dyn_cast<GetElementPtrInst>(U))
if (GEP->hasAllZeroIndices()) {
- TryInsertToQueue(U);
+ LoadOperandsQueue.push_back(U);
continue;
}
Modified: llvm/trunk/test/Transforms/GVN/invariant.group.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/invariant.group.ll?rev=291405&r1=291404&r2=291405&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/invariant.group.ll (original)
+++ llvm/trunk/test/Transforms/GVN/invariant.group.ll Sun Jan 8 16:26:06 2017
@@ -344,11 +344,63 @@ _Z1gR1A.exit:
ret void
}
+; Check if no optimizations are performed with global pointers.
+; FIXME: we could do the optimizations if we would check if dependency comes
+; from the same function.
+; CHECK-LABEL: define void @testGlobal() {
+define void @testGlobal() {
+; CHECK: %a = load i8, i8* @unknownPtr, !invariant.group !0
+ %a = load i8, i8* @unknownPtr, !invariant.group !0
+ call void @foo2(i8* @unknownPtr, i8 %a)
+; CHECK: %1 = load i8, i8* @unknownPtr, !invariant.group !0
+ %1 = load i8, i8* @unknownPtr, !invariant.group !0
+ call void @bar(i8 %1)
+
+ %b0 = bitcast i8* @unknownPtr to i1*
+ call void @fooBit(i1* %b0, i1 1)
+; Adding regex because of canonicalization of bitcasts
+; CHECK: %2 = load i1, i1* {{.*}}, !invariant.group !0
+ %2 = load i1, i1* %b0, !invariant.group !0
+ call void @fooBit(i1* %b0, i1 %2)
+; CHECK: %3 = load i1, i1* {{.*}}, !invariant.group !0
+ %3 = load i1, i1* %b0, !invariant.group !0
+ call void @fooBit(i1* %b0, i1 %3)
+ ret void
+}
+; And in the case it is not global
+; CHECK-LABEL: define void @testNotGlobal() {
+define void @testNotGlobal() {
+ %a = alloca i8
+ call void @foo(i8* %a)
+; CHECK: %b = load i8, i8* %a, !invariant.group !0
+ %b = load i8, i8* %a, !invariant.group !0
+ call void @foo2(i8* %a, i8 %b)
+
+ %1 = load i8, i8* %a, !invariant.group !0
+; CHECK: call void @bar(i8 %b)
+ call void @bar(i8 %1)
+
+ %b0 = bitcast i8* %a to i1*
+ call void @fooBit(i1* %b0, i1 1)
+; CHECK: %trunc = trunc i8 %b to i1
+ %2 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+ call void @fooBit(i1* %b0, i1 %2)
+ %3 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+ call void @fooBit(i1* %b0, i1 %3)
+ ret void
+}
+
+
declare void @foo(i8*)
+declare void @foo2(i8*, i8)
declare void @bar(i8)
declare i8* @getPointer(i8*)
declare void @_ZN1A3fooEv(%struct.A*)
declare void @_ZN1AC1Ev(%struct.A*)
+declare void @fooBit(i1*, i1)
+
declare i8* @llvm.invariant.group.barrier(i8*)
; Function Attrs: nounwind
Modified: llvm/trunk/test/Transforms/NewGVN/invariant.group.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/NewGVN/invariant.group.ll?rev=291405&r1=291404&r2=291405&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/NewGVN/invariant.group.ll (original)
+++ llvm/trunk/test/Transforms/NewGVN/invariant.group.ll Sun Jan 8 16:26:06 2017
@@ -345,11 +345,63 @@ _Z1gR1A.exit:
ret void
}
+; Check if no optimizations are performed with global pointers.
+; FIXME: we could do the optimizations if we would check if dependency comes
+; from the same function.
+; CHECK-LABEL: define void @testGlobal() {
+define void @testGlobal() {
+; CHECK: %a = load i8, i8* @unknownPtr, !invariant.group !0
+ %a = load i8, i8* @unknownPtr, !invariant.group !0
+ call void @foo2(i8* @unknownPtr, i8 %a)
+; CHECK: %1 = load i8, i8* @unknownPtr, !invariant.group !0
+ %1 = load i8, i8* @unknownPtr, !invariant.group !0
+ call void @bar(i8 %1)
+
+ %b0 = bitcast i8* @unknownPtr to i1*
+ call void @fooBit(i1* %b0, i1 1)
+; Adding regex because of canonicalization of bitcasts
+; CHECK: %2 = load i1, i1* {{.*}}, !invariant.group !0
+ %2 = load i1, i1* %b0, !invariant.group !0
+ call void @fooBit(i1* %b0, i1 %2)
+; CHECK: %3 = load i1, i1* {{.*}}, !invariant.group !0
+ %3 = load i1, i1* %b0, !invariant.group !0
+ call void @fooBit(i1* %b0, i1 %3)
+ ret void
+}
+; And in the case it is not global
+; CHECK-LABEL: define void @testNotGlobal() {
+define void @testNotGlobal() {
+ %a = alloca i8
+ call void @foo(i8* %a)
+; CHECK: %b = load i8, i8* %a, !invariant.group !0
+ %b = load i8, i8* %a, !invariant.group !0
+ call void @foo2(i8* %a, i8 %b)
+
+ %1 = load i8, i8* %a, !invariant.group !0
+; CHECK: call void @bar(i8 %b)
+ call void @bar(i8 %1)
+
+ %b0 = bitcast i8* %a to i1*
+ call void @fooBit(i1* %b0, i1 1)
+; CHECK: %trunc = trunc i8 %b to i1
+ %2 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+ call void @fooBit(i1* %b0, i1 %2)
+ %3 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+ call void @fooBit(i1* %b0, i1 %3)
+ ret void
+}
+
+
declare void @foo(i8*)
+declare void @foo2(i8*, i8)
declare void @bar(i8)
declare i8* @getPointer(i8*)
declare void @_ZN1A3fooEv(%struct.A*)
declare void @_ZN1AC1Ev(%struct.A*)
+declare void @fooBit(i1*, i1)
+
declare i8* @llvm.invariant.group.barrier(i8*)
; Function Attrs: nounwind
More information about the llvm-commits
mailing list