[clang] 9fbd33a - [OMPIRBuilder] Add support for simd (loop) directive.
Arnamoy Bhattacharyya via cfe-commits
cfe-commits at lists.llvm.org
Wed Jan 19 08:29:23 PST 2022
Author: Arnamoy Bhattacharyya
Date: 2022-01-19T11:32:17-05:00
New Revision: 9fbd33ad623d2b576fc563545bbdf2c257cdf709
URL: https://github.com/llvm/llvm-project/commit/9fbd33ad623d2b576fc563545bbdf2c257cdf709
DIFF: https://github.com/llvm/llvm-project/commit/9fbd33ad623d2b576fc563545bbdf2c257cdf709.diff
LOG: [OMPIRBuilder] Add support for simd (loop) directive.
This patch adds OMPIRBuilder support for the simd directive (without any clause). This will be a first step towards lowering simd directive in LLVM_Flang. The patch uses existing CanonicalLoop infrastructure of IRBuilder to add the support. Also adds necessary code to add llvm.access.group and llvm.loop metadata wherever needed.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D114379
Added:
clang/test/OpenMP/irbuilder_simd.cpp
Modified:
clang/lib/CodeGen/CGStmtOpenMP.cpp
llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 11af2812a4118..0db59dd2624c5 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -2584,7 +2584,67 @@ static void emitOMPSimdRegion(CodeGenFunction &CGF, const OMPLoopDirective &S,
}
}
+static bool isSupportedByOpenMPIRBuilder(const OMPExecutableDirective &S) {
+ // Check for unsupported clauses
+ if (!S.clauses().empty()) {
+ // Currently no clause is supported
+ return false;
+ }
+
+ // Check if we have a statement with the ordered directive.
+ // Visit the statement hierarchy to find a compound statement
+ // with a ordered directive in it.
+ if (const auto *CanonLoop = dyn_cast<OMPCanonicalLoop>(S.getRawStmt())) {
+ if (const Stmt *SyntacticalLoop = CanonLoop->getLoopStmt()) {
+ for (const Stmt *SubStmt : SyntacticalLoop->children()) {
+ if (!SubStmt)
+ continue;
+ if (const CompoundStmt *CS = dyn_cast<CompoundStmt>(SubStmt)) {
+ for (const Stmt *CSSubStmt : CS->children()) {
+ if (!CSSubStmt)
+ continue;
+ if (isa<OMPOrderedDirective>(CSSubStmt)) {
+ return false;
+ }
+ }
+ }
+ }
+ }
+ }
+ return true;
+}
+
void CodeGenFunction::EmitOMPSimdDirective(const OMPSimdDirective &S) {
+ bool UseOMPIRBuilder =
+ CGM.getLangOpts().OpenMPIRBuilder && isSupportedByOpenMPIRBuilder(S);
+ if (UseOMPIRBuilder) {
+ auto &&CodeGenIRBuilder = [this, &S, UseOMPIRBuilder](CodeGenFunction &CGF,
+ PrePostActionTy &) {
+ // Use the OpenMPIRBuilder if enabled.
+ if (UseOMPIRBuilder) {
+ // Emit the associated statement and get its loop representation.
+ llvm::DebugLoc DL = SourceLocToDebugLoc(S.getBeginLoc());
+ const Stmt *Inner = S.getRawStmt();
+ llvm::CanonicalLoopInfo *CLI =
+ EmitOMPCollapsedCanonicalLoopNest(Inner, 1);
+
+ llvm::OpenMPIRBuilder &OMPBuilder =
+ CGM.getOpenMPRuntime().getOMPBuilder();
+ // Add SIMD specific metadata
+ OMPBuilder.applySimd(DL, CLI);
+ return;
+ }
+ };
+ {
+ auto LPCRegion =
+ CGOpenMPRuntime::LastprivateConditionalRAII::disable(*this, S);
+ OMPLexicalScope Scope(*this, S, OMPD_unknown);
+ CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_simd,
+ CodeGenIRBuilder);
+ }
+ return;
+ }
+
ParentLoopDirectiveForScanRegion ScanRegion(*this, S);
OMPFirstScanLoop = true;
auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
diff --git a/clang/test/OpenMP/irbuilder_simd.cpp b/clang/test/OpenMP/irbuilder_simd.cpp
new file mode 100644
index 0000000000000..9f369290f2db5
--- /dev/null
+++ b/clang/test/OpenMP/irbuilder_simd.cpp
@@ -0,0 +1,71 @@
+// RUN: %clang_cc1 -fopenmp-enable-irbuilder -verify -fopenmp -fopenmp-version=45 -x c++ -triple x86_64-unknown-unknown -emit-llvm %s -o - | FileCheck %s
+// expected-no-diagnostics
+
+struct S {
+ int a, b;
+};
+
+struct P {
+ int a, b;
+};
+
+void simple(float *a, float *b, int *c) {
+ S s, *p;
+ P pp;
+#pragma omp simd
+ for (int i = 3; i < 32; i += 5) {
+ // llvm.access.group test
+ // CHECK: %[[A_ADDR:.+]] = alloca float*, align 8
+ // CHECK: %[[B_ADDR:.+]] = alloca float*, align 8
+ // CHECK: %[[S:.+]] = alloca %struct.S, align 4
+ // CHECK: %[[P:.+]] = alloca %struct.S*, align 8
+ // CHECK: %[[I:.+]] = alloca i32, align 4
+ // CHECK: %[[TMP3:.+]] = load float*, float** %[[B_ADDR:.+]], align 8, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[TMP4:.+]] = load i32, i32* %[[I:.+]], align 4, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[IDXPROM:.+]] = sext i32 %[[TMP4:.+]] to i64
+ // CHECK-NEXT: %[[ARRAYIDX:.+]] = getelementptr inbounds float, float* %[[TMP3:.+]], i64 %[[IDXPROM:.+]]
+ // CHECK-NEXT: %[[TMP5:.+]] = load float, float* %[[ARRAYIDX:.+]], align 4, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[A2:.+]] = getelementptr inbounds %struct.S, %struct.S* %[[S:.+]], i32 0, i32 0
+ // CHECK-NEXT: %[[TMP6:.+]] = load i32, i32* %[[A2:.+]], align 4, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[CONV:.+]] = sitofp i32 %[[TMP6:.+]] to float
+ // CHECK-NEXT: %[[ADD:.+]] = fadd float %[[TMP5:.+]], %[[CONV:.+]]
+ // CHECK-NEXT: %[[TMP7:.+]] = load %struct.S*, %struct.S** %[[P:.+]], align 8, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[A3:.+]] = getelementptr inbounds %struct.S, %struct.S* %[[TMP7:.+]], i32 0, i32 0
+ // CHECK-NEXT: %[[TMP8:.+]] = load i32, i32* %[[A3:.+]], align 4, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[CONV4:.+]] = sitofp i32 %[[TMP8:.+]] to float
+ // CHECK-NEXT: %[[ADD5:.+]] = fadd float %[[ADD:.+]], %[[CONV4:.+]]
+ // CHECK-NEXT: %[[TMP9:.+]] = load float*, float** %[[A_ADDR:.+]], align 8, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[TMP10:.+]] = load i32, i32* %[[I:.+]], align 4, !llvm.access.group ![[META3:[0-9]+]]
+ // CHECK-NEXT: %[[IDXPROM6:.+]] = sext i32 %[[TMP10:.+]] to i64
+ // CHECK-NEXT: %[[ARRAYIDX7:.+]] = getelementptr inbounds float, float* %[[TMP9:.+]], i64 %[[IDXPROM6:.+]]
+ // CHECK-NEXT: store float %[[ADD5:.+]], float* %[[ARRAYIDX7:.+]], align 4, !llvm.access.group ![[META3:[0-9]+]]
+ // llvm.loop test
+ // CHECK: %[[OMP_LOOPDOTNEXT:.+]] = add nuw i32 %[[OMP_LOOPDOTIV:.+]], 1
+ // CHECK-NEXT: br label %omp_loop.header, !llvm.loop ![[META4:[0-9]+]]
+ a[i] = b[i] + s.a + p->a;
+ }
+
+#pragma omp simd
+ for (int j = 3; j < 32; j += 5) {
+ // test if unique access groups were used for a second loop
+ // CHECK: %[[A22:.+]] = getelementptr inbounds %struct.P, %struct.P* %[[PP:.+]], i32 0, i32 0
+ // CHECK-NEXT: %[[TMP14:.+]] = load i32, i32* %[[A22:.+]], align 4, !llvm.access.group ![[META7:[0-9]+]]
+ // CHECK-NEXT: %[[TMP15:.+]] = load i32*, i32** %[[C_ADDR:.+]], align 8, !llvm.access.group ![[META7:[0-9]+]]
+ // CHECK-NEXT: %[[TMP16:.+]] = load i32, i32* %[[J:.+]], align 4, !llvm.access.group ![[META7:[0-9]+]]
+ // CHECK-NEXT: %[[IDXPROM23:.+]] = sext i32 %[[TMP16:.+]] to i64
+ // CHECK-NEXT: %[[ARRAYIDX24:.+]] = getelementptr inbounds i32, i32* %[[TMP15:.+]], i64 %[[IDXPROM23:.+]]
+ // CHECK-NEXT: store i32 %[[TMP14:.+]], i32* %[[ARRAYIDX24:.+]], align 4, !llvm.access.group ![[META7:[0-9]+]]
+ // check llvm.loop metadata
+ // CHECK: %[[OMP_LOOPDOTNEXT:.+]] = add nuw i32 %[[OMP_LOOPDOTIV:.+]], 1
+ // CHECK-NEXT: br label %[[OMP_LLOP_BODY:.*]], !llvm.loop ![[META8:[0-9]+]]
+ c[j] = pp.a;
+ }
+}
+
+// CHECK: ![[META3:[0-9]+]] = distinct !{}
+// CHECK-NEXT: ![[META4]] = distinct !{![[META4]], ![[META5:[0-9]+]], ![[META6:[0-9]+]]}
+// CHECK-NEXT: ![[META5]] = !{!"llvm.loop.parallel_accesses", ![[META3]]}
+// CHECK-NEXT: ![[META6]] = !{!"llvm.loop.vectorize.enable", i1 true}
+// CHECK-NEXT: ![[META7:[0-9]+]] = distinct !{}
+// CHECK-NEXT: ![[META8]] = distinct !{![[META8]], ![[META9:[0-9]+]], ![[META6]]}
+// CHECK-NEXT: ![[META9]] = !{!"llvm.loop.parallel_accesses", ![[META7]]}
\ No newline at end of file
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h b/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
index d80c521a5acfe..cfebdbd7b2217 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
+++ b/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
@@ -517,6 +517,12 @@ class OpenMPIRBuilder {
void unrollLoopPartial(DebugLoc DL, CanonicalLoopInfo *Loop, int32_t Factor,
CanonicalLoopInfo **UnrolledCLI);
+ /// Add metadata to simd-ize a loop.
+ ///
+ /// \param DL Debug location for instructions added by unrolling.
+ /// \param Loop The loop to simd-ize.
+ void applySimd(DebugLoc DL, CanonicalLoopInfo *Loop);
+
/// Generator for '#omp flush'
///
/// \param Loc The location where the flush directive was encountered
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
index 61194da4b589d..62bef5259877a 100644
--- a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
+++ b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -13,6 +13,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/AssumptionCache.h"
@@ -2145,6 +2146,19 @@ static void addLoopMetadata(CanonicalLoopInfo *Loop,
Latch->getTerminator()->setMetadata(LLVMContext::MD_loop, LoopID);
}
+/// Attach llvm.access.group metadata to the memref instructions of \p Block
+static void addSimdMetadata(BasicBlock *Block, MDNode *AccessGroup,
+ LoopInfo &LI) {
+ for (Instruction &I : *Block) {
+ if (I.mayReadOrWriteMemory()) {
+ // TODO: This instruction may already have access group from
+ // other pragmas e.g. #pragma clang loop vectorize. Append
+ // so that the existing metadata is not overwritten.
+ I.setMetadata(LLVMContext::MD_access_group, AccessGroup);
+ }
+ }
+}
+
void OpenMPIRBuilder::unrollLoopFull(DebugLoc, CanonicalLoopInfo *Loop) {
LLVMContext &Ctx = Builder.getContext();
addLoopMetadata(
@@ -2160,6 +2174,53 @@ void OpenMPIRBuilder::unrollLoopHeuristic(DebugLoc, CanonicalLoopInfo *Loop) {
});
}
+void OpenMPIRBuilder::applySimd(DebugLoc, CanonicalLoopInfo *CanonicalLoop) {
+ LLVMContext &Ctx = Builder.getContext();
+
+ Function *F = CanonicalLoop->getFunction();
+
+ FunctionAnalysisManager FAM;
+ FAM.registerPass([]() { return DominatorTreeAnalysis(); });
+ FAM.registerPass([]() { return LoopAnalysis(); });
+ FAM.registerPass([]() { return PassInstrumentationAnalysis(); });
+
+ LoopAnalysis LIA;
+ LoopInfo &&LI = LIA.run(*F, FAM);
+
+ Loop *L = LI.getLoopFor(CanonicalLoop->getHeader());
+
+ SmallSet<BasicBlock *, 8> Reachable;
+
+ // Get the basic blocks from the loop in which memref instructions
+ // can be found.
+ // TODO: Generalize getting all blocks inside a CanonicalizeLoopInfo,
+ // preferably without running any passes.
+ for (BasicBlock *Block : L->getBlocks()) {
+ if (Block == CanonicalLoop->getCond() ||
+ Block == CanonicalLoop->getHeader())
+ continue;
+ Reachable.insert(Block);
+ }
+
+ // Add access group metadata to memory-access instructions.
+ MDNode *AccessGroup = MDNode::getDistinct(Ctx, {});
+ for (BasicBlock *BB : Reachable)
+ addSimdMetadata(BB, AccessGroup, LI);
+
+ // Use the above access group metadata to create loop level
+ // metadata, which should be distinct for each loop.
+ ConstantAsMetadata *BoolConst =
+ ConstantAsMetadata::get(ConstantInt::getTrue(Type::getInt1Ty(Ctx)));
+ // TODO: If the loop has existing parallel access metadata, have
+ // to combine two lists.
+ addLoopMetadata(
+ CanonicalLoop,
+ {MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.parallel_accesses"),
+ AccessGroup}),
+ MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.vectorize.enable"),
+ BoolConst})});
+}
+
/// Create the TargetMachine object to query the backend for optimization
/// preferences.
///
diff --git a/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp b/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
index 4a75a8aed4e67..d00f799d30c0e 100644
--- a/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
+++ b/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
@@ -1662,6 +1662,37 @@ TEST_F(OpenMPIRBuilderTest, TileSingleLoopCounts) {
EXPECT_FALSE(verifyModule(*M, &errs()));
}
+TEST_F(OpenMPIRBuilderTest, ApplySimd) {
+ OpenMPIRBuilder OMPBuilder(*M);
+
+ CanonicalLoopInfo *CLI = buildSingleLoopFunction(DL, OMPBuilder);
+
+ // Simd-ize the loop.
+ OMPBuilder.applySimd(DL, CLI);
+
+ OMPBuilder.finalize();
+ EXPECT_FALSE(verifyModule(*M, &errs()));
+
+ PassBuilder PB;
+ FunctionAnalysisManager FAM;
+ PB.registerFunctionAnalyses(FAM);
+ LoopInfo &LI = FAM.getResult<LoopAnalysis>(*F);
+
+ const std::vector<Loop *> &TopLvl = LI.getTopLevelLoops();
+ EXPECT_EQ(TopLvl.size(), 1u);
+
+ Loop *L = TopLvl.front();
+ EXPECT_TRUE(findStringMetadataForLoop(L, "llvm.loop.parallel_accesses"));
+ EXPECT_TRUE(getBooleanLoopAttribute(L, "llvm.loop.vectorize.enable"));
+
+ // Check for llvm.access.group metadata attached to the printf
+ // function in the loop body.
+ BasicBlock *LoopBody = CLI->getBody();
+ EXPECT_TRUE(any_of(*LoopBody, [](Instruction &I) {
+ return I.getMetadata("llvm.access.group") != nullptr;
+ }));
+}
+
TEST_F(OpenMPIRBuilderTest, UnrollLoopFull) {
OpenMPIRBuilder OMPBuilder(*M);
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