[llvm] 984bca9 - [GVN][NewGVN] Take call attributes into account in expressions (#114545)
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Fri Nov 8 00:00:52 PST 2024
Author: Yingwei Zheng
Date: 2024-11-08T16:00:48+08:00
New Revision: 984bca9d1faaa1fa5c694f8f2a5524b2374d204a
URL: https://github.com/llvm/llvm-project/commit/984bca9d1faaa1fa5c694f8f2a5524b2374d204a
DIFF: https://github.com/llvm/llvm-project/commit/984bca9d1faaa1fa5c694f8f2a5524b2374d204a.diff
LOG: [GVN][NewGVN] Take call attributes into account in expressions (#114545)
Drop `canBeReplacedBy` and take call attributes into account in
expressions.
Address comment
https://github.com/llvm/llvm-project/pull/114011#pullrequestreview-2409772313.
Added:
Modified:
llvm/include/llvm/Transforms/Scalar/GVNExpression.h
llvm/lib/Transforms/Scalar/GVN.cpp
llvm/lib/Transforms/Scalar/NewGVN.cpp
llvm/test/Transforms/GVN/pr113997.ll
llvm/test/Transforms/NewGVN/pr113997.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/Scalar/GVNExpression.h b/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
index 2433890d0df802..71437953640c9b 100644
--- a/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
+++ b/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
@@ -315,6 +315,12 @@ class CallExpression final : public MemoryExpression {
return EB->getExpressionType() == ET_Call;
}
+ bool equals(const Expression &Other) const override;
+ bool exactlyEquals(const Expression &Other) const override {
+ return Expression::exactlyEquals(Other) &&
+ cast<CallExpression>(Other).Call == Call;
+ }
+
// Debugging support
void printInternal(raw_ostream &OS, bool PrintEType) const override {
if (PrintEType)
diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index 8bc2c710ec1744..e27f5a08c85a97 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -143,6 +143,8 @@ struct llvm::GVNPass::Expression {
Type *type = nullptr;
SmallVector<uint32_t, 4> varargs;
+ AttributeList attrs;
+
Expression(uint32_t o = ~2U) : opcode(o) {}
bool operator==(const Expression &other) const {
@@ -154,6 +156,9 @@ struct llvm::GVNPass::Expression {
return false;
if (varargs != other.varargs)
return false;
+ if (!attrs.isEmpty() && !other.attrs.isEmpty() &&
+ !attrs.intersectWith(type->getContext(), other.attrs).has_value())
+ return false;
return true;
}
@@ -364,6 +369,8 @@ GVNPass::Expression GVNPass::ValueTable::createExpr(Instruction *I) {
} else if (auto *SVI = dyn_cast<ShuffleVectorInst>(I)) {
ArrayRef<int> ShuffleMask = SVI->getShuffleMask();
e.varargs.append(ShuffleMask.begin(), ShuffleMask.end());
+ } else if (auto *CB = dyn_cast<CallBase>(I)) {
+ e.attrs = CB->getAttributes();
}
return e;
@@ -2136,16 +2143,6 @@ bool GVNPass::processAssumeIntrinsic(AssumeInst *IntrinsicI) {
return Changed;
}
-// Return true iff V1 can be replaced with V2.
-static bool canBeReplacedBy(Value *V1, Value *V2) {
- if (auto *CB1 = dyn_cast<CallBase>(V1))
- if (auto *CB2 = dyn_cast<CallBase>(V2))
- return CB1->getAttributes()
- .intersectWith(CB2->getContext(), CB2->getAttributes())
- .has_value();
- return true;
-}
-
static void patchAndReplaceAllUsesWith(Instruction *I, Value *Repl) {
patchReplacementInstruction(I, Repl);
I->replaceAllUsesWith(Repl);
@@ -2690,7 +2687,7 @@ bool GVNPass::processInstruction(Instruction *I) {
// Perform fast-path value-number based elimination of values inherited from
// dominators.
Value *Repl = findLeader(I->getParent(), Num);
- if (!Repl || !canBeReplacedBy(I, Repl)) {
+ if (!Repl) {
// Failure, just remember this instance for future use.
LeaderTable.insert(Num, I, I->getParent());
return false;
@@ -2956,7 +2953,7 @@ bool GVNPass::performScalarPRE(Instruction *CurInst) {
uint32_t TValNo = VN.phiTranslate(P, CurrentBlock, ValNo, *this);
Value *predV = findLeader(P, TValNo);
- if (!predV || !canBeReplacedBy(CurInst, predV)) {
+ if (!predV) {
predMap.push_back(std::make_pair(static_cast<Value *>(nullptr), P));
PREPred = P;
++NumWithout;
diff --git a/llvm/lib/Transforms/Scalar/NewGVN.cpp b/llvm/lib/Transforms/Scalar/NewGVN.cpp
index 6800ad51cc0a8f..0cba8739441bcb 100644
--- a/llvm/lib/Transforms/Scalar/NewGVN.cpp
+++ b/llvm/lib/Transforms/Scalar/NewGVN.cpp
@@ -945,6 +945,18 @@ bool StoreExpression::equals(const Expression &Other) const {
return true;
}
+bool CallExpression::equals(const Expression &Other) const {
+ if (!MemoryExpression::equals(Other))
+ return false;
+
+ if (auto *RHS = dyn_cast<CallExpression>(&Other))
+ return Call->getAttributes()
+ .intersectWith(Call->getContext(), RHS->Call->getAttributes())
+ .has_value();
+
+ return false;
+}
+
// Determine if the edge From->To is a backedge
bool NewGVN::isBackedge(BasicBlock *From, BasicBlock *To) const {
return From == To ||
@@ -3854,16 +3866,6 @@ Value *NewGVN::findPHIOfOpsLeader(const Expression *E,
return nullptr;
}
-// Return true iff V1 can be replaced with V2.
-static bool canBeReplacedBy(Value *V1, Value *V2) {
- if (auto *CB1 = dyn_cast<CallBase>(V1))
- if (auto *CB2 = dyn_cast<CallBase>(V2))
- return CB1->getAttributes()
- .intersectWith(CB2->getContext(), CB2->getAttributes())
- .has_value();
- return true;
-}
-
bool NewGVN::eliminateInstructions(Function &F) {
// This is a non-standard eliminator. The normal way to eliminate is
// to walk the dominator tree in order, keeping track of available
@@ -3973,8 +3975,6 @@ bool NewGVN::eliminateInstructions(Function &F) {
MembersLeft.insert(Member);
continue;
}
- if (!canBeReplacedBy(Member, Leader))
- continue;
LLVM_DEBUG(dbgs() << "Found replacement " << *(Leader) << " for "
<< *Member << "\n");
@@ -4082,11 +4082,8 @@ bool NewGVN::eliminateInstructions(Function &F) {
if (DominatingLeader != Def) {
// Even if the instruction is removed, we still need to update
// flags/metadata due to downstreams users of the leader.
- if (!match(DefI, m_Intrinsic<Intrinsic::ssa_copy>())) {
- if (!canBeReplacedBy(DefI, DominatingLeader))
- continue;
+ if (!match(DefI, m_Intrinsic<Intrinsic::ssa_copy>()))
patchReplacementInstruction(DefI, DominatingLeader);
- }
markInstructionForDeletion(DefI);
}
@@ -4134,11 +4131,8 @@ bool NewGVN::eliminateInstructions(Function &F) {
// original operand, as we already know we can just drop it.
auto *ReplacedInst = cast<Instruction>(U->get());
auto *PI = PredInfo->getPredicateInfoFor(ReplacedInst);
- if (!PI || DominatingLeader != PI->OriginalOp) {
- if (!canBeReplacedBy(ReplacedInst, DominatingLeader))
- continue;
+ if (!PI || DominatingLeader != PI->OriginalOp)
patchReplacementInstruction(ReplacedInst, DominatingLeader);
- }
LLVM_DEBUG(dbgs()
<< "Found replacement " << *DominatingLeader << " for "
diff --git a/llvm/test/Transforms/GVN/pr113997.ll b/llvm/test/Transforms/GVN/pr113997.ll
index 35e73b1a4439b3..6aebdb3a5dfac3 100644
--- a/llvm/test/Transforms/GVN/pr113997.ll
+++ b/llvm/test/Transforms/GVN/pr113997.ll
@@ -31,3 +31,39 @@ if.else:
if.then:
ret i1 false
}
+
+; Make sure we don't merge these two users of the incompatible call pair.
+
+define i1 @bucket2(i32 noundef %x) {
+; CHECK-LABEL: define i1 @bucket2(
+; CHECK-SAME: i32 noundef [[X:%.*]]) {
+; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 [[X]], 0
+; CHECK-NEXT: [[CTPOP1:%.*]] = tail call range(i32 1, 32) i32 @llvm.ctpop.i32(i32 zeroext [[X]])
+; CHECK-NEXT: [[CTPOP1INC:%.*]] = add i32 [[CTPOP1]], 1
+; CHECK-NEXT: [[CMP2:%.*]] = icmp samesign ult i32 [[CTPOP1INC]], 3
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP1]], i1 [[CMP2]], i1 false
+; CHECK-NEXT: br i1 [[COND]], label %[[IF_THEN:.*]], label %[[IF_ELSE:.*]]
+; CHECK: [[IF_ELSE]]:
+; CHECK-NEXT: [[CTPOP2:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
+; CHECK-NEXT: [[CTPOP2INC:%.*]] = add i32 [[CTPOP2]], 1
+; CHECK-NEXT: [[RES:%.*]] = icmp eq i32 [[CTPOP2INC]], 2
+; CHECK-NEXT: ret i1 [[RES]]
+; CHECK: [[IF_THEN]]:
+; CHECK-NEXT: ret i1 false
+;
+ %cmp1 = icmp sgt i32 %x, 0
+ %ctpop1 = tail call range(i32 1, 32) i32 @llvm.ctpop.i32(i32 zeroext %x)
+ %ctpop1inc = add i32 %ctpop1, 1
+ %cmp2 = icmp samesign ult i32 %ctpop1inc, 3
+ %cond = select i1 %cmp1, i1 %cmp2, i1 false
+ br i1 %cond, label %if.then, label %if.else
+
+if.else:
+ %ctpop2 = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 %x)
+ %ctpop2inc = add i32 %ctpop2, 1
+ %res = icmp eq i32 %ctpop2inc, 2
+ ret i1 %res
+
+if.then:
+ ret i1 false
+}
diff --git a/llvm/test/Transforms/NewGVN/pr113997.ll b/llvm/test/Transforms/NewGVN/pr113997.ll
index a919c8c304b1b9..59dce09e89c887 100644
--- a/llvm/test/Transforms/NewGVN/pr113997.ll
+++ b/llvm/test/Transforms/NewGVN/pr113997.ll
@@ -31,3 +31,39 @@ if.else:
if.then:
ret i1 false
}
+
+; Make sure we don't merge these two users of the incompatible call pair.
+
+define i1 @bucket2(i32 noundef %x) {
+; CHECK-LABEL: define i1 @bucket2(
+; CHECK-SAME: i32 noundef [[X:%.*]]) {
+; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 [[X]], 0
+; CHECK-NEXT: [[CTPOP1:%.*]] = tail call range(i32 1, 32) i32 @llvm.ctpop.i32(i32 zeroext [[X]])
+; CHECK-NEXT: [[CTPOP1INC:%.*]] = add i32 [[CTPOP1]], 1
+; CHECK-NEXT: [[CMP2:%.*]] = icmp samesign ult i32 [[CTPOP1INC]], 3
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP1]], i1 [[CMP2]], i1 false
+; CHECK-NEXT: br i1 [[COND]], label %[[IF_THEN:.*]], label %[[IF_ELSE:.*]]
+; CHECK: [[IF_ELSE]]:
+; CHECK-NEXT: [[CTPOP2:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
+; CHECK-NEXT: [[CTPOP2INC:%.*]] = add i32 [[CTPOP2]], 1
+; CHECK-NEXT: [[RES:%.*]] = icmp eq i32 [[CTPOP2INC]], 2
+; CHECK-NEXT: ret i1 [[RES]]
+; CHECK: [[IF_THEN]]:
+; CHECK-NEXT: ret i1 false
+;
+ %cmp1 = icmp sgt i32 %x, 0
+ %ctpop1 = tail call range(i32 1, 32) i32 @llvm.ctpop.i32(i32 zeroext %x)
+ %ctpop1inc = add i32 %ctpop1, 1
+ %cmp2 = icmp samesign ult i32 %ctpop1inc, 3
+ %cond = select i1 %cmp1, i1 %cmp2, i1 false
+ br i1 %cond, label %if.then, label %if.else
+
+if.else:
+ %ctpop2 = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 %x)
+ %ctpop2inc = add i32 %ctpop2, 1
+ %res = icmp eq i32 %ctpop2inc, 2
+ ret i1 %res
+
+if.then:
+ ret i1 false
+}
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