[SandboxVec][DAG] Fix DAG when old interval is mem free #126983
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This patch fixes a bug in `DependencyGraph::extend()` when the old interval contains no memory instructions. When this is the case we should do a full dependency scan of the new interval.
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@llvm/pr-subscribers-llvm-transforms Author: vporpo (vporpo) ChangesThis patch fixes a bug in Full diff: https://github.com/llvm/llvm-project/pull/126983.diff 2 Files Affected:
diff --git a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
index 06a5e3bed7f03..098b296c30ab8 100644
--- a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
+++ b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
@@ -122,6 +122,8 @@ MemDGNodeIntervalBuilder::getBotMemDGNode(const Interval<Instruction> &Intvl,
Interval<MemDGNode>
MemDGNodeIntervalBuilder::make(const Interval<Instruction> &Instrs,
DependencyGraph &DAG) {
+ if (Instrs.empty())
+ return {};
auto *TopMemN = getTopMemDGNode(Instrs, DAG);
// If we couldn't find a mem node in range TopN - BotN then it's empty.
if (TopMemN == nullptr)
@@ -529,8 +531,8 @@ Interval<Instruction> DependencyGraph::extend(ArrayRef<Instruction *> Instrs) {
}
}
};
- if (DAGInterval.empty()) {
- assert(NewInterval == InstrsInterval && "Expected empty DAGInterval!");
+ auto MemDAGInterval = MemDGNodeIntervalBuilder::make(DAGInterval, *this);
+ if (MemDAGInterval.empty()) {
FullScan(NewInterval);
}
// 2. The new section is below the old section.
@@ -550,8 +552,7 @@ Interval<Instruction> DependencyGraph::extend(ArrayRef<Instruction *> Instrs) {
// range including both NewInterval and DAGInterval until DstN, for each DstN.
else if (DAGInterval.bottom()->comesBefore(NewInterval.top())) {
auto DstRange = MemDGNodeIntervalBuilder::make(NewInterval, *this);
- auto SrcRangeFull = MemDGNodeIntervalBuilder::make(
- DAGInterval.getUnionInterval(NewInterval), *this);
+ auto SrcRangeFull = MemDAGInterval.getUnionInterval(DstRange);
for (MemDGNode &DstN : DstRange) {
auto SrcRange =
Interval<MemDGNode>(SrcRangeFull.top(), DstN.getPrevNode());
@@ -589,7 +590,7 @@ Interval<Instruction> DependencyGraph::extend(ArrayRef<Instruction *> Instrs) {
// When scanning for deps with destination in DAGInterval we need to
// consider sources from the NewInterval only, because all intra-DAGInterval
// dependencies have already been created.
- auto DstRangeOld = MemDGNodeIntervalBuilder::make(DAGInterval, *this);
+ auto DstRangeOld = MemDAGInterval;
auto SrcRange = MemDGNodeIntervalBuilder::make(NewInterval, *this);
for (MemDGNode &DstN : DstRangeOld)
scanAndAddDeps(DstN, SrcRange);
diff --git a/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp b/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp
index f1e9afefb4531..37f29428e900a 100644
--- a/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp
+++ b/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp
@@ -1013,3 +1013,42 @@ define void @foo(ptr %ptr, i8 %v1, i8 %v2, i8 %arg) {
EXPECT_EQ(S2N->getNextNode(), S1N);
EXPECT_EQ(S1N->getNextNode(), nullptr);
}
+
+// Extending an "Old" interval with no mem instructions.
+TEST_F(DependencyGraphTest, ExtendDAGWithNoMem) {
+ parseIR(C, R"IR(
+define void @foo(ptr %ptr, i8 %v, i8 %v0, i8 %v1, i8 %v2, i8 %v3) {
+ store i8 %v0, ptr %ptr
+ store i8 %v1, ptr %ptr
+ %zext1 = zext i8 %v to i32
+ %zext2 = zext i8 %v to i32
+ store i8 %v2, ptr %ptr
+ store i8 %v3, ptr %ptr
+ ret void
+}
+)IR");
+ llvm::Function *LLVMF = &*M->getFunction("foo");
+ sandboxir::Context Ctx(C);
+ auto *F = Ctx.createFunction(LLVMF);
+ auto *BB = &*F->begin();
+ auto It = BB->begin();
+ auto *S0 = cast<sandboxir::StoreInst>(&*It++);
+ auto *S1 = cast<sandboxir::StoreInst>(&*It++);
+ auto *Z1 = cast<sandboxir::CastInst>(&*It++);
+ auto *Z2 = cast<sandboxir::CastInst>(&*It++);
+ auto *S2 = cast<sandboxir::StoreInst>(&*It++);
+ auto *S3 = cast<sandboxir::StoreInst>(&*It++);
+
+ sandboxir::DependencyGraph DAG(getAA(*LLVMF), Ctx);
+ // Create a non-empty DAG that contains no memory instructions.
+ DAG.extend({Z1, Z2});
+ // Now extend it downwards.
+ DAG.extend({S2, S3});
+ EXPECT_TRUE(memDependency(DAG.getNode(S2), DAG.getNode(S3)));
+
+ // Same but upwards.
+ DAG.clear();
+ DAG.extend({Z1, Z2});
+ DAG.extend({S0, S1});
+ EXPECT_TRUE(memDependency(DAG.getNode(S0), DAG.getNode(S1)));
+}
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@llvm/pr-subscribers-vectorizers Author: vporpo (vporpo) ChangesThis patch fixes a bug in Full diff: https://github.com/llvm/llvm-project/pull/126983.diff 2 Files Affected:
diff --git a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
index 06a5e3bed7f03..098b296c30ab8 100644
--- a/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
+++ b/llvm/lib/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.cpp
@@ -122,6 +122,8 @@ MemDGNodeIntervalBuilder::getBotMemDGNode(const Interval<Instruction> &Intvl,
Interval<MemDGNode>
MemDGNodeIntervalBuilder::make(const Interval<Instruction> &Instrs,
DependencyGraph &DAG) {
+ if (Instrs.empty())
+ return {};
auto *TopMemN = getTopMemDGNode(Instrs, DAG);
// If we couldn't find a mem node in range TopN - BotN then it's empty.
if (TopMemN == nullptr)
@@ -529,8 +531,8 @@ Interval<Instruction> DependencyGraph::extend(ArrayRef<Instruction *> Instrs) {
}
}
};
- if (DAGInterval.empty()) {
- assert(NewInterval == InstrsInterval && "Expected empty DAGInterval!");
+ auto MemDAGInterval = MemDGNodeIntervalBuilder::make(DAGInterval, *this);
+ if (MemDAGInterval.empty()) {
FullScan(NewInterval);
}
// 2. The new section is below the old section.
@@ -550,8 +552,7 @@ Interval<Instruction> DependencyGraph::extend(ArrayRef<Instruction *> Instrs) {
// range including both NewInterval and DAGInterval until DstN, for each DstN.
else if (DAGInterval.bottom()->comesBefore(NewInterval.top())) {
auto DstRange = MemDGNodeIntervalBuilder::make(NewInterval, *this);
- auto SrcRangeFull = MemDGNodeIntervalBuilder::make(
- DAGInterval.getUnionInterval(NewInterval), *this);
+ auto SrcRangeFull = MemDAGInterval.getUnionInterval(DstRange);
for (MemDGNode &DstN : DstRange) {
auto SrcRange =
Interval<MemDGNode>(SrcRangeFull.top(), DstN.getPrevNode());
@@ -589,7 +590,7 @@ Interval<Instruction> DependencyGraph::extend(ArrayRef<Instruction *> Instrs) {
// When scanning for deps with destination in DAGInterval we need to
// consider sources from the NewInterval only, because all intra-DAGInterval
// dependencies have already been created.
- auto DstRangeOld = MemDGNodeIntervalBuilder::make(DAGInterval, *this);
+ auto DstRangeOld = MemDAGInterval;
auto SrcRange = MemDGNodeIntervalBuilder::make(NewInterval, *this);
for (MemDGNode &DstN : DstRangeOld)
scanAndAddDeps(DstN, SrcRange);
diff --git a/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp b/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp
index f1e9afefb4531..37f29428e900a 100644
--- a/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp
+++ b/llvm/unittests/Transforms/Vectorize/SandboxVectorizer/DependencyGraphTest.cpp
@@ -1013,3 +1013,42 @@ define void @foo(ptr %ptr, i8 %v1, i8 %v2, i8 %arg) {
EXPECT_EQ(S2N->getNextNode(), S1N);
EXPECT_EQ(S1N->getNextNode(), nullptr);
}
+
+// Extending an "Old" interval with no mem instructions.
+TEST_F(DependencyGraphTest, ExtendDAGWithNoMem) {
+ parseIR(C, R"IR(
+define void @foo(ptr %ptr, i8 %v, i8 %v0, i8 %v1, i8 %v2, i8 %v3) {
+ store i8 %v0, ptr %ptr
+ store i8 %v1, ptr %ptr
+ %zext1 = zext i8 %v to i32
+ %zext2 = zext i8 %v to i32
+ store i8 %v2, ptr %ptr
+ store i8 %v3, ptr %ptr
+ ret void
+}
+)IR");
+ llvm::Function *LLVMF = &*M->getFunction("foo");
+ sandboxir::Context Ctx(C);
+ auto *F = Ctx.createFunction(LLVMF);
+ auto *BB = &*F->begin();
+ auto It = BB->begin();
+ auto *S0 = cast<sandboxir::StoreInst>(&*It++);
+ auto *S1 = cast<sandboxir::StoreInst>(&*It++);
+ auto *Z1 = cast<sandboxir::CastInst>(&*It++);
+ auto *Z2 = cast<sandboxir::CastInst>(&*It++);
+ auto *S2 = cast<sandboxir::StoreInst>(&*It++);
+ auto *S3 = cast<sandboxir::StoreInst>(&*It++);
+
+ sandboxir::DependencyGraph DAG(getAA(*LLVMF), Ctx);
+ // Create a non-empty DAG that contains no memory instructions.
+ DAG.extend({Z1, Z2});
+ // Now extend it downwards.
+ DAG.extend({S2, S3});
+ EXPECT_TRUE(memDependency(DAG.getNode(S2), DAG.getNode(S3)));
+
+ // Same but upwards.
+ DAG.clear();
+ DAG.extend({Z1, Z2});
+ DAG.extend({S0, S1});
+ EXPECT_TRUE(memDependency(DAG.getNode(S0), DAG.getNode(S1)));
+}
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tmsri
approved these changes
Feb 12, 2025
flovent
pushed a commit
to flovent/llvm-project
that referenced
this pull request
Feb 13, 2025
This patch fixes a bug in `DependencyGraph::extend()` when the old interval contains no memory instructions. When this is the case we should do a full dependency scan of the new interval.
joaosaffran
pushed a commit
to joaosaffran/llvm-project
that referenced
this pull request
Feb 14, 2025
This patch fixes a bug in `DependencyGraph::extend()` when the old interval contains no memory instructions. When this is the case we should do a full dependency scan of the new interval.
sivan-shani
pushed a commit
to sivan-shani/llvm-project
that referenced
this pull request
Feb 24, 2025
This patch fixes a bug in `DependencyGraph::extend()` when the old interval contains no memory instructions. When this is the case we should do a full dependency scan of the new interval.
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This patch fixes a bug in
DependencyGraph::extend()when the old interval contains no memory instructions. When this is the case we should do a full dependency scan of the new interval.