[llvm] [CVP][LVI] Add support for InsertElementInst in LVI (PR #99368)
Rajat Bajpai via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 18 09:37:11 PDT 2024
https://github.com/rajatbajpai updated https://github.com/llvm/llvm-project/pull/99368
>From 2f6512680394a53ecff040dc7828b87267278cdb Mon Sep 17 00:00:00 2001
From: rbajpai <rbajpai at nvidia.com>
Date: Fri, 5 Jul 2024 12:05:34 +0530
Subject: [PATCH 1/3] Currently, the LVI analysis pass doesn't support
InsertElementInst vector instruction. Due to this, some optimization
opportunities are missed. For example, in the below example, ICMP instruction
can be folded but it doesn't.
```
...
%ie1 = insertelement <2 x i32> poison, i32 10, i64 0
%ie2 = insertelement <2 x i32> %ie1, i32 20, i64 1
%icmp = icmp <2 x i1> %ie2, <i32 40, i32 40>
...
```
This change adds InsertElementInst support in the LVI analysis pass to fix the motivating
example.
---
llvm/lib/Analysis/LazyValueInfo.cpp | 36 +++++++++
.../insertelement.ll | 76 +++++++++++++++++++
2 files changed, 112 insertions(+)
create mode 100644 llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index 92389f2896b8e..d28d4fa47fdae 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -428,6 +428,8 @@ class LazyValueInfoImpl {
std::optional<ValueLatticeElement> solveBlockValueIntrinsic(IntrinsicInst *II,
BasicBlock *BB);
std::optional<ValueLatticeElement>
+ solveBlockValueInsertElement(InsertElementInst *IEI, BasicBlock *BB);
+ std::optional<ValueLatticeElement>
solveBlockValueExtractValue(ExtractValueInst *EVI, BasicBlock *BB);
bool isNonNullAtEndOfBlock(Value *Val, BasicBlock *BB);
void intersectAssumeOrGuardBlockValueConstantRange(Value *Val,
@@ -657,6 +659,9 @@ LazyValueInfoImpl::solveBlockValueImpl(Value *Val, BasicBlock *BB) {
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(BBI))
return solveBlockValueBinaryOp(BO, BB);
+ if (auto *IEI = dyn_cast<InsertElementInst>(BBI))
+ return solveBlockValueInsertElement(IEI, BB);
+
if (auto *EVI = dyn_cast<ExtractValueInst>(BBI))
return solveBlockValueExtractValue(EVI, BB);
@@ -1038,6 +1043,37 @@ LazyValueInfoImpl::solveBlockValueIntrinsic(IntrinsicInst *II, BasicBlock *BB) {
MetadataVal);
}
+std::optional<ValueLatticeElement>
+LazyValueInfoImpl::solveBlockValueInsertElement(InsertElementInst *IEI,
+ BasicBlock *BB) {
+ std::optional<ValueLatticeElement> OptEltVal =
+ getBlockValue(IEI->getOperand(1), BB, IEI);
+ if (!OptEltVal)
+ return std::nullopt;
+ ValueLatticeElement &EltVal = *OptEltVal;
+
+ if (auto *CV = dyn_cast<ConstantVector>(IEI->getOperand(0))) {
+ // Must be vector of integers. Merge these elements to create
+ // the range.
+ for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
+ Constant *Elem = CV->getAggregateElement(i);
+ if (isa<PoisonValue>(Elem))
+ continue;
+ std::optional<ConstantRange> CR = getRangeFor(Elem, IEI, BB);
+ if (!CR)
+ return std::nullopt;
+ EltVal.mergeIn(ValueLatticeElement::getRange(*CR));
+ }
+ } else if (!isa<PoisonValue>(IEI->getOperand(0))) {
+ std::optional<ValueLatticeElement> OptVecResult =
+ solveBlockValueImpl(IEI->getOperand(0), BB);
+ if (!OptVecResult)
+ return std::nullopt;
+ EltVal.mergeIn(*OptVecResult);
+ }
+ return EltVal;
+}
+
std::optional<ValueLatticeElement>
LazyValueInfoImpl::solveBlockValueExtractValue(ExtractValueInst *EVI,
BasicBlock *BB) {
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll b/llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll
new file mode 100644
index 0000000000000..769f431738342
--- /dev/null
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll
@@ -0,0 +1,76 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=correlated-propagation -S | FileCheck %s
+
+;; Check if ICMP instruction is constant folded or not.
+
+define void @test1(ptr addrspace(1) %out) {
+; CHECK-LABEL: define void @test1(
+; CHECK-SAME: ptr addrspace(1) [[OUT:%.*]]) {
+; CHECK-NEXT: [[CALL:%.*]] = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range [[RNG0:![0-9]+]]
+; CHECK-NEXT: [[UDIV_LHS_TRUNC:%.*]] = trunc i32 [[CALL]] to i16
+; CHECK-NEXT: [[UDIV1:%.*]] = udiv i16 [[UDIV_LHS_TRUNC]], 5
+; CHECK-NEXT: [[UDIV_ZEXT:%.*]] = zext i16 [[UDIV1]] to i32
+; CHECK-NEXT: [[ADD1:%.*]] = add nuw nsw i32 [[UDIV_ZEXT]], 768
+; CHECK-NEXT: [[ADD2:%.*]] = add nuw nsw i32 [[UDIV_ZEXT]], 896
+; CHECK-NEXT: [[IE1:%.*]] = insertelement <2 x i32> poison, i32 [[ADD1]], i64 0
+; CHECK-NEXT: [[IE2:%.*]] = insertelement <2 x i32> [[IE1]], i32 [[ADD2]], i64 1
+; CHECK-NEXT: [[EI1:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 0
+; CHECK-NEXT: [[EI2:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 1
+; CHECK-NEXT: [[ADDUP:%.*]] = add i1 [[EI1]], [[EI2]]
+; CHECK-NEXT: [[ADDUP_UPCAST:%.*]] = zext i1 [[ADDUP]] to i32
+; CHECK-NEXT: store i32 [[ADDUP_UPCAST]], ptr addrspace(1) [[OUT]], align 4
+; CHECK-NEXT: ret void
+;
+ %call = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range !1
+ %udiv = udiv i32 %call, 5
+ %add1 = add i32 %udiv, 768
+ %add2 = add i32 %udiv, 896
+ %ie1 = insertelement <2 x i32> poison, i32 %add1, i64 0
+ %ie2 = insertelement <2 x i32> %ie1, i32 %add2, i64 1
+ %icmp1 = icmp slt <2 x i32> %ie2, <i32 1024, i32 1024>
+ %ei1 = extractelement <2 x i1> %icmp1, i64 0
+ %ei2 = extractelement <2 x i1> %icmp1, i64 1
+ %addUp = add i1 %ei1, %ei2
+ %addUp.upcast = zext i1 %addUp to i32
+ store i32 %addUp.upcast, ptr addrspace(1) %out, align 4
+ ret void
+}
+
+
+;; Check if LVI is able to handle constant vector operands
+;; in InsertElementInst and CVP is able to fold ICMP instruction.
+
+define void @test2(ptr addrspace(1) %out) {
+; CHECK-LABEL: define void @test2(
+; CHECK-SAME: ptr addrspace(1) [[OUT:%.*]]) {
+; CHECK-NEXT: [[CALL:%.*]] = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range [[RNG0]]
+; CHECK-NEXT: [[UDIV_LHS_TRUNC:%.*]] = trunc i32 [[CALL]] to i16
+; CHECK-NEXT: [[UDIV1:%.*]] = udiv i16 [[UDIV_LHS_TRUNC]], 5
+; CHECK-NEXT: [[UDIV_ZEXT:%.*]] = zext i16 [[UDIV1]] to i32
+; CHECK-NEXT: [[ADD2:%.*]] = add nuw nsw i32 [[UDIV_ZEXT]], 896
+; CHECK-NEXT: [[IE1:%.*]] = insertelement <2 x i32> <i32 poison, i32 1>, i32 [[ADD2]], i64 0
+; CHECK-NEXT: [[EI1:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 0
+; CHECK-NEXT: [[EI2:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 1
+; CHECK-NEXT: [[ADDUP:%.*]] = add i1 [[EI1]], [[EI2]]
+; CHECK-NEXT: [[ADDUP_UPCAST:%.*]] = zext i1 [[ADDUP]] to i32
+; CHECK-NEXT: store i32 [[ADDUP_UPCAST]], ptr addrspace(1) [[OUT]], align 4
+; CHECK-NEXT: ret void
+;
+ %call = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range !1
+ %udiv = udiv i32 %call, 5
+ %add2 = add i32 %udiv, 896
+ %ie1 = insertelement <2 x i32> <i32 poison, i32 1>, i32 %add2, i64 0
+ %icmp1 = icmp slt <2 x i32> %ie1, <i32 1024, i32 1024>
+ %ei1 = extractelement <2 x i1> %icmp1, i64 0
+ %ei2 = extractelement <2 x i1> %icmp1, i64 1
+ %addUp = add i1 %ei1, %ei2
+ %addUp.upcast = zext i1 %addUp to i32
+ store i32 %addUp.upcast, ptr addrspace(1) %out, align 4
+ ret void
+}
+
+
+!1 = !{i32 0, i32 640}
+;.
+; CHECK: [[RNG0]] = !{i32 0, i32 640}
+;.
>From f1bf8795ada6b9055c6e8e183a26f7d1c0dd537a Mon Sep 17 00:00:00 2001
From: rbajpai <rbajpai at nvidia.com>
Date: Thu, 18 Jul 2024 13:54:32 +0530
Subject: [PATCH 2/3] Addressed review comments. Moved `ConstantVector` logic
inside `getBlockValue` function.
---
llvm/lib/Analysis/LazyValueInfo.cpp | 48 ++++++------
.../insertelement.ll | 76 -------------------
.../CorrelatedValuePropagation/vectors.ll | 25 ++++++
3 files changed, 51 insertions(+), 98 deletions(-)
delete mode 100644 llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index d28d4fa47fdae..8a14fae13327f 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -572,6 +572,23 @@ void LazyValueInfoImpl::solve() {
std::optional<ValueLatticeElement>
LazyValueInfoImpl::getBlockValue(Value *Val, BasicBlock *BB,
Instruction *CxtI) {
+ if (auto *CV = dyn_cast<ConstantVector>(Val)) {
+ // Must be vector of integers. Merge these elements to create
+ // the range.
+ ValueLatticeElement Res;
+ for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
+ Constant *Elem = CV->getAggregateElement(i);
+ if (isa<PoisonValue>(Elem))
+ continue;
+ std::optional<ValueLatticeElement> ElemVal =
+ getBlockValue(Elem, BB, CxtI);
+ if (!ElemVal)
+ return std::nullopt;
+ Res.mergeIn(*ElemVal);
+ }
+ return Res;
+ }
+
// If already a constant, there is nothing to compute.
if (Constant *VC = dyn_cast<Constant>(Val))
return ValueLatticeElement::get(VC);
@@ -1045,33 +1062,20 @@ LazyValueInfoImpl::solveBlockValueIntrinsic(IntrinsicInst *II, BasicBlock *BB) {
std::optional<ValueLatticeElement>
LazyValueInfoImpl::solveBlockValueInsertElement(InsertElementInst *IEI,
- BasicBlock *BB) {
+ BasicBlock *BB) {
std::optional<ValueLatticeElement> OptEltVal =
getBlockValue(IEI->getOperand(1), BB, IEI);
if (!OptEltVal)
return std::nullopt;
- ValueLatticeElement &EltVal = *OptEltVal;
+ ValueLatticeElement &Res = *OptEltVal;
- if (auto *CV = dyn_cast<ConstantVector>(IEI->getOperand(0))) {
- // Must be vector of integers. Merge these elements to create
- // the range.
- for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
- Constant *Elem = CV->getAggregateElement(i);
- if (isa<PoisonValue>(Elem))
- continue;
- std::optional<ConstantRange> CR = getRangeFor(Elem, IEI, BB);
- if (!CR)
- return std::nullopt;
- EltVal.mergeIn(ValueLatticeElement::getRange(*CR));
- }
- } else if (!isa<PoisonValue>(IEI->getOperand(0))) {
- std::optional<ValueLatticeElement> OptVecResult =
- solveBlockValueImpl(IEI->getOperand(0), BB);
- if (!OptVecResult)
- return std::nullopt;
- EltVal.mergeIn(*OptVecResult);
- }
- return EltVal;
+ std::optional<ValueLatticeElement> OptVecVal =
+ getBlockValue(IEI->getOperand(0), BB, IEI);
+ if (!OptVecVal)
+ return std::nullopt;
+
+ Res.mergeIn(*OptVecVal);
+ return Res;
}
std::optional<ValueLatticeElement>
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll b/llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll
deleted file mode 100644
index 769f431738342..0000000000000
--- a/llvm/test/Transforms/CorrelatedValuePropagation/insertelement.ll
+++ /dev/null
@@ -1,76 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
-; RUN: opt < %s -passes=correlated-propagation -S | FileCheck %s
-
-;; Check if ICMP instruction is constant folded or not.
-
-define void @test1(ptr addrspace(1) %out) {
-; CHECK-LABEL: define void @test1(
-; CHECK-SAME: ptr addrspace(1) [[OUT:%.*]]) {
-; CHECK-NEXT: [[CALL:%.*]] = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range [[RNG0:![0-9]+]]
-; CHECK-NEXT: [[UDIV_LHS_TRUNC:%.*]] = trunc i32 [[CALL]] to i16
-; CHECK-NEXT: [[UDIV1:%.*]] = udiv i16 [[UDIV_LHS_TRUNC]], 5
-; CHECK-NEXT: [[UDIV_ZEXT:%.*]] = zext i16 [[UDIV1]] to i32
-; CHECK-NEXT: [[ADD1:%.*]] = add nuw nsw i32 [[UDIV_ZEXT]], 768
-; CHECK-NEXT: [[ADD2:%.*]] = add nuw nsw i32 [[UDIV_ZEXT]], 896
-; CHECK-NEXT: [[IE1:%.*]] = insertelement <2 x i32> poison, i32 [[ADD1]], i64 0
-; CHECK-NEXT: [[IE2:%.*]] = insertelement <2 x i32> [[IE1]], i32 [[ADD2]], i64 1
-; CHECK-NEXT: [[EI1:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 0
-; CHECK-NEXT: [[EI2:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 1
-; CHECK-NEXT: [[ADDUP:%.*]] = add i1 [[EI1]], [[EI2]]
-; CHECK-NEXT: [[ADDUP_UPCAST:%.*]] = zext i1 [[ADDUP]] to i32
-; CHECK-NEXT: store i32 [[ADDUP_UPCAST]], ptr addrspace(1) [[OUT]], align 4
-; CHECK-NEXT: ret void
-;
- %call = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range !1
- %udiv = udiv i32 %call, 5
- %add1 = add i32 %udiv, 768
- %add2 = add i32 %udiv, 896
- %ie1 = insertelement <2 x i32> poison, i32 %add1, i64 0
- %ie2 = insertelement <2 x i32> %ie1, i32 %add2, i64 1
- %icmp1 = icmp slt <2 x i32> %ie2, <i32 1024, i32 1024>
- %ei1 = extractelement <2 x i1> %icmp1, i64 0
- %ei2 = extractelement <2 x i1> %icmp1, i64 1
- %addUp = add i1 %ei1, %ei2
- %addUp.upcast = zext i1 %addUp to i32
- store i32 %addUp.upcast, ptr addrspace(1) %out, align 4
- ret void
-}
-
-
-;; Check if LVI is able to handle constant vector operands
-;; in InsertElementInst and CVP is able to fold ICMP instruction.
-
-define void @test2(ptr addrspace(1) %out) {
-; CHECK-LABEL: define void @test2(
-; CHECK-SAME: ptr addrspace(1) [[OUT:%.*]]) {
-; CHECK-NEXT: [[CALL:%.*]] = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range [[RNG0]]
-; CHECK-NEXT: [[UDIV_LHS_TRUNC:%.*]] = trunc i32 [[CALL]] to i16
-; CHECK-NEXT: [[UDIV1:%.*]] = udiv i16 [[UDIV_LHS_TRUNC]], 5
-; CHECK-NEXT: [[UDIV_ZEXT:%.*]] = zext i16 [[UDIV1]] to i32
-; CHECK-NEXT: [[ADD2:%.*]] = add nuw nsw i32 [[UDIV_ZEXT]], 896
-; CHECK-NEXT: [[IE1:%.*]] = insertelement <2 x i32> <i32 poison, i32 1>, i32 [[ADD2]], i64 0
-; CHECK-NEXT: [[EI1:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 0
-; CHECK-NEXT: [[EI2:%.*]] = extractelement <2 x i1> <i1 true, i1 true>, i64 1
-; CHECK-NEXT: [[ADDUP:%.*]] = add i1 [[EI1]], [[EI2]]
-; CHECK-NEXT: [[ADDUP_UPCAST:%.*]] = zext i1 [[ADDUP]] to i32
-; CHECK-NEXT: store i32 [[ADDUP_UPCAST]], ptr addrspace(1) [[OUT]], align 4
-; CHECK-NEXT: ret void
-;
- %call = call i32 @llvm.nvvm.read.ptx.sreg.tid.x(), !range !1
- %udiv = udiv i32 %call, 5
- %add2 = add i32 %udiv, 896
- %ie1 = insertelement <2 x i32> <i32 poison, i32 1>, i32 %add2, i64 0
- %icmp1 = icmp slt <2 x i32> %ie1, <i32 1024, i32 1024>
- %ei1 = extractelement <2 x i1> %icmp1, i64 0
- %ei2 = extractelement <2 x i1> %icmp1, i64 1
- %addUp = add i1 %ei1, %ei2
- %addUp.upcast = zext i1 %addUp to i32
- store i32 %addUp.upcast, ptr addrspace(1) %out, align 4
- ret void
-}
-
-
-!1 = !{i32 0, i32 640}
-;.
-; CHECK: [[RNG0]] = !{i32 0, i32 640}
-;.
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/vectors.ll b/llvm/test/Transforms/CorrelatedValuePropagation/vectors.ll
index 6254b54d42554..351a2c79cdff4 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/vectors.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/vectors.ll
@@ -327,3 +327,28 @@ join:
%add = add <2 x i16> %phi, <i16 2, i16 3>
ret <2 x i16> %add
}
+
+;; Check if ICMP instruction is constant folded or not.
+define <2 x i1> @insertelement_fold1() {
+; CHECK-LABEL: define <2 x i1> @insertelement_fold1() {
+; CHECK-NEXT: [[IE1:%.*]] = insertelement <2 x i32> poison, i32 10, i64 0
+; CHECK-NEXT: [[IE2:%.*]] = insertelement <2 x i32> [[IE1]], i32 20, i64 1
+; CHECK-NEXT: ret <2 x i1> <i1 true, i1 true>
+;
+ %ie1 = insertelement <2 x i32> poison, i32 10, i64 0
+ %ie2 = insertelement <2 x i32> %ie1, i32 20, i64 1
+ %icmp1 = icmp slt <2 x i32> %ie2, <i32 1024, i32 1024>
+ ret <2 x i1> %icmp1
+}
+
+;; Check if LVI is able to handle constant vector operands
+;; in InsertElementInst and CVP is able to fold ICMP instruction.
+define <2 x i1> @insertelement_fold2() {
+; CHECK-LABEL: define <2 x i1> @insertelement_fold2() {
+; CHECK-NEXT: [[IE1:%.*]] = insertelement <2 x i32> <i32 poison, i32 20>, i32 10, i64 0
+; CHECK-NEXT: ret <2 x i1> <i1 true, i1 true>
+;
+ %ie1 = insertelement <2 x i32> <i32 poison, i32 20>, i32 10, i64 0
+ %icmp1 = icmp slt <2 x i32> %ie1, <i32 1024, i32 1024>
+ ret <2 x i1> %icmp1
+}
>From 5e2a073d89d6b35a6ce05e029c112d6fe32bf2ed Mon Sep 17 00:00:00 2001
From: rbajpai <rbajpai at nvidia.com>
Date: Thu, 18 Jul 2024 22:02:52 +0530
Subject: [PATCH 3/3] Removed `ConstantVector` handling from `getBlockValue`
---
llvm/lib/Analysis/LazyValueInfo.cpp | 17 -----------------
1 file changed, 17 deletions(-)
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index 8a14fae13327f..4c023ed5ed8f0 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -572,23 +572,6 @@ void LazyValueInfoImpl::solve() {
std::optional<ValueLatticeElement>
LazyValueInfoImpl::getBlockValue(Value *Val, BasicBlock *BB,
Instruction *CxtI) {
- if (auto *CV = dyn_cast<ConstantVector>(Val)) {
- // Must be vector of integers. Merge these elements to create
- // the range.
- ValueLatticeElement Res;
- for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
- Constant *Elem = CV->getAggregateElement(i);
- if (isa<PoisonValue>(Elem))
- continue;
- std::optional<ValueLatticeElement> ElemVal =
- getBlockValue(Elem, BB, CxtI);
- if (!ElemVal)
- return std::nullopt;
- Res.mergeIn(*ElemVal);
- }
- return Res;
- }
-
// If already a constant, there is nothing to compute.
if (Constant *VC = dyn_cast<Constant>(Val))
return ValueLatticeElement::get(VC);
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