[polly] r218793 - Annotate LLVM-IR for all parallel loops
Johannes Doerfert
doerfert at cs.uni-saarland.de
Wed Oct 1 13:10:44 PDT 2014
Author: jdoerfert
Date: Wed Oct 1 15:10:44 2014
New Revision: 218793
URL: http://llvm.org/viewvc/llvm-project?rev=218793&view=rev
Log:
Annotate LLVM-IR for all parallel loops
This change allows to annotate all parallel loops with loop id metadata.
Furthermore, it will annotate memory instructions with
llvm.mem.parallel_loop_access metadata for all surrounding parallel loops.
This is especially usefull if an external paralleliser is used.
This also removes the PollyLoopInfo class and comments the
LoopAnnotator.
A test case for multiple parallel loops is attached.
Added:
polly/trunk/test/Isl/CodeGen/LoopParallelMD/loop_nest_param_parallel.ll
Modified:
polly/trunk/include/polly/CodeGen/IRBuilder.h
polly/trunk/lib/CodeGen/IRBuilder.cpp
polly/trunk/lib/CodeGen/IslCodeGeneration.cpp
polly/trunk/lib/CodeGen/LoopGenerators.cpp
Modified: polly/trunk/include/polly/CodeGen/IRBuilder.h
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/include/polly/CodeGen/IRBuilder.h?rev=218793&r1=218792&r2=218793&view=diff
==============================================================================
--- polly/trunk/include/polly/CodeGen/IRBuilder.h (original)
+++ polly/trunk/include/polly/CodeGen/IRBuilder.h Wed Oct 1 15:10:44 2014
@@ -16,54 +16,35 @@
#define POLLY_CODEGEN_IRBUILDER_H
#include "llvm/IR/IRBuilder.h"
+#include "llvm/Analysis/LoopInfo.h"
+
namespace polly {
-/// @brief Keeps information about generated loops.
-class PollyLoopInfo {
+/// @brief Helper class to annotate newly generated loops with metadata.
+///
+/// This stack-like structure will keep track of all loops, and annotate
+/// memory instructions and loop headers according to all parallel loops.
+class LoopAnnotator {
public:
- PollyLoopInfo(llvm::BasicBlock *Header)
- : LoopID(0), Header(Header), Parallel(false) {}
+ /// @brief Add a new loop @p L which is parallel if @p IsParallel is true.
+ void pushLoop(llvm::Loop *L, bool IsParallel);
- /// @brief Get the loop id metadata node.
- ///
- /// Each loop is identified by a self referencing metadata node of the form:
- ///
- /// '!n = metadata !{metadata !n}'
- ///
- /// This functions creates such metadata on demand if not yet available.
- ///
- /// @return The loop id metadata node.
- llvm::MDNode *GetLoopID() const;
-
- /// @brief Get the head basic block of this loop.
- llvm::BasicBlock *GetHeader() const { return Header; }
-
- /// @brief Check if the loop is parallel.
- ///
- /// @return True, if the loop is parallel.
- bool IsParallel() const { return Parallel; }
-
- /// @brief Set a loop as parallel.
- ///
- /// @IsParallel True, if the loop is to be marked as parallel. False, if the
- // loop should be marked sequential.
- void SetParallel(bool IsParallel = true) { Parallel = IsParallel; }
+ /// @brief Remove the last added loop.
+ void popLoop(bool isParallel);
-private:
- mutable llvm::MDNode *LoopID;
- llvm::BasicBlock *Header;
- bool Parallel;
-};
+ /// @brief Annotate the new instruction @p I for all parallel loops.
+ void annotate(llvm::Instruction *I);
-class LoopAnnotator {
-public:
- void Begin(llvm::BasicBlock *Header);
- void SetCurrentParallel();
- void End();
- void Annotate(llvm::Instruction *I);
+ /// @brief Annotate the loop latch @p B wrt. @p L.
+ void annotateLoopLatch(llvm::BranchInst *B, llvm::Loop *L,
+ bool IsParallel) const;
private:
- std::vector<PollyLoopInfo> Active;
+ /// @brief All loops currently under construction.
+ llvm::SmallVector<llvm::Loop *, 8> ActiveLoops;
+
+ /// @brief Metadata pointing to parallel loops currently under construction.
+ llvm::SmallVector<llvm::MDNode *, 8> ParallelLoops;
};
/// @brief Add Polly specifics when running IRBuilder.
@@ -84,7 +65,7 @@ protected:
llvm::IRBuilderDefaultInserter<PreserveNames>::InsertHelper(I, Name, BB,
InsertPt);
if (Annotator)
- Annotator->Annotate(I);
+ Annotator->annotate(I);
}
private:
Modified: polly/trunk/lib/CodeGen/IRBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/CodeGen/IRBuilder.cpp?rev=218793&r1=218792&r2=218793&view=diff
==============================================================================
--- polly/trunk/lib/CodeGen/IRBuilder.cpp (original)
+++ polly/trunk/lib/CodeGen/IRBuilder.cpp Wed Oct 1 15:10:44 2014
@@ -13,48 +13,66 @@
//===----------------------------------------------------------------------===//
#include "polly/CodeGen/IRBuilder.h"
-#include "llvm/Analysis/LoopInfo.h"
+
#include "llvm/IR/Metadata.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
using namespace polly;
-llvm::MDNode *polly::PollyLoopInfo::GetLoopID() const {
- if (LoopID)
- return LoopID;
-
- llvm::Value *Args[] = {0};
- LoopID = llvm::MDNode::get(Header->getContext(), Args);
+/// @brief Get the loop id metadata node.
+///
+/// Each loop is identified by a self referencing metadata node of the form:
+///
+/// '!n = metadata !{metadata !n}'
+///
+/// This functions creates such metadata on demand if not yet available.
+///
+/// @return The loop id metadata node.
+static MDNode *getLoopID(Loop *L) {
+ Value *Args[] = {0};
+ MDNode *LoopID = MDNode::get(L->getHeader()->getContext(), Args);
LoopID->replaceOperandWith(0, LoopID);
return LoopID;
}
-void polly::LoopAnnotator::Begin(llvm::BasicBlock *Header) {
- Active.push_back(PollyLoopInfo(Header));
+void polly::LoopAnnotator::pushLoop(Loop *L, bool IsParallel) {
+ ActiveLoops.push_back(L);
+ if (!IsParallel)
+ return;
+
+ BasicBlock *Header = L->getHeader();
+ MDNode *Id = getLoopID(L);
+ Value *Args[] = {Id};
+ MDNode *Ids = ParallelLoops.empty()
+ ? MDNode::get(Header->getContext(), Args)
+ : MDNode::concatenate(ParallelLoops.back(), Id);
+ ParallelLoops.push_back(Ids);
}
-void polly::LoopAnnotator::End() { Active.pop_back(); }
+void polly::LoopAnnotator::popLoop(bool IsParallel) {
+ ActiveLoops.pop_back();
+ if (!IsParallel)
+ return;
-void polly::LoopAnnotator::SetCurrentParallel() {
- Active.back().SetParallel(true);
+ assert(!ParallelLoops.empty() && "Expected a parallel loop to pop");
+ ParallelLoops.pop_back();
}
-void polly::LoopAnnotator::Annotate(llvm::Instruction *Inst) {
- if (Active.empty())
+void polly::LoopAnnotator::annotateLoopLatch(BranchInst *B, Loop *L,
+ bool IsParallel) const {
+ if (!IsParallel)
return;
- const PollyLoopInfo &L = Active.back();
- if (!L.IsParallel())
+ assert(!ParallelLoops.empty() && "Expected a parallel loop to annotate");
+ MDNode *Ids = ParallelLoops.back();
+ MDNode *Id = cast<MDNode>(Ids->getOperand(Ids->getNumOperands() - 1));
+ B->setMetadata("llvm.loop", Id);
+}
+
+void polly::LoopAnnotator::annotate(Instruction *Inst) {
+ if (!Inst->mayReadOrWriteMemory() || ParallelLoops.empty())
return;
- if (TerminatorInst *TI = dyn_cast<llvm::TerminatorInst>(Inst)) {
- for (unsigned i = 0, ie = TI->getNumSuccessors(); i != ie; ++i)
- if (TI->getSuccessor(i) == L.GetHeader()) {
- TI->setMetadata("llvm.loop", L.GetLoopID());
- break;
- }
- } else if (Inst->mayReadOrWriteMemory()) {
- Inst->setMetadata("llvm.mem.parallel_loop_access", L.GetLoopID());
- }
+ Inst->setMetadata("llvm.mem.parallel_loop_access", ParallelLoops.back());
}
Modified: polly/trunk/lib/CodeGen/IslCodeGeneration.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/CodeGen/IslCodeGeneration.cpp?rev=218793&r1=218792&r2=218793&view=diff
==============================================================================
--- polly/trunk/lib/CodeGen/IslCodeGeneration.cpp (original)
+++ polly/trunk/lib/CodeGen/IslCodeGeneration.cpp Wed Oct 1 15:10:44 2014
@@ -319,8 +319,8 @@ void IslNodeBuilder::createForSequential
CmpInst::Predicate Predicate;
bool Parallel;
- Parallel = IslAstInfo::isInnermostParallel(For) &&
- !IslAstInfo::isReductionParallel(For);
+ Parallel =
+ IslAstInfo::isParallel(For) && !IslAstInfo::isReductionParallel(For);
Body = isl_ast_node_for_get_body(For);
@@ -362,7 +362,7 @@ void IslNodeBuilder::createForSequential
create(Body);
- Annotator.End();
+ Annotator.popLoop(Parallel);
IDToValue.erase(IteratorID);
Modified: polly/trunk/lib/CodeGen/LoopGenerators.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/CodeGen/LoopGenerators.cpp?rev=218793&r1=218792&r2=218793&view=diff
==============================================================================
--- polly/trunk/lib/CodeGen/LoopGenerators.cpp (original)
+++ polly/trunk/lib/CodeGen/LoopGenerators.cpp Wed Oct 1 15:10:44 2014
@@ -64,12 +64,6 @@ Value *polly::createLoop(Value *LB, Valu
BasicBlock *PreHeaderBB =
BasicBlock::Create(Context, "polly.loop_preheader", F);
- if (Annotator) {
- Annotator->Begin(HeaderBB);
- if (Parallel)
- Annotator->SetCurrentParallel();
- }
-
// Update LoopInfo
Loop *OuterLoop = LI.getLoopFor(BeforeBB);
Loop *NewLoop = new Loop();
@@ -86,6 +80,11 @@ Value *polly::createLoop(Value *LB, Valu
NewLoop->addBasicBlockToLoop(HeaderBB, LI.getBase());
+ // Notify the annotator (if present) that we have a new loop, but only
+ // after the header block is set.
+ if (Annotator)
+ Annotator->pushLoop(NewLoop, Parallel);
+
// ExitBB
ExitBB = SplitBlock(BeforeBB, Builder.GetInsertPoint()++, P);
ExitBB->setName("polly.loop_exit");
@@ -122,7 +121,12 @@ Value *polly::createLoop(Value *LB, Valu
UB = Builder.CreateSub(UB, Stride, "polly.adjust_ub");
LoopCondition = Builder.CreateICmp(Predicate, IV, UB);
LoopCondition->setName("polly.loop_cond");
- Builder.CreateCondBr(LoopCondition, HeaderBB, ExitBB);
+
+ // Create the loop latch and annotate it as such.
+ BranchInst *B = Builder.CreateCondBr(LoopCondition, HeaderBB, ExitBB);
+ if (Annotator)
+ Annotator->annotateLoopLatch(B, NewLoop, Parallel);
+
IV->addIncoming(IncrementedIV, HeaderBB);
if (GuardBB)
DT.changeImmediateDominator(ExitBB, GuardBB);
Added: polly/trunk/test/Isl/CodeGen/LoopParallelMD/loop_nest_param_parallel.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/Isl/CodeGen/LoopParallelMD/loop_nest_param_parallel.ll?rev=218793&view=auto
==============================================================================
--- polly/trunk/test/Isl/CodeGen/LoopParallelMD/loop_nest_param_parallel.ll (added)
+++ polly/trunk/test/Isl/CodeGen/LoopParallelMD/loop_nest_param_parallel.ll Wed Oct 1 15:10:44 2014
@@ -0,0 +1,64 @@
+; RUN: opt %loadPolly -polly-codegen-isl -polly-ast-detect-parallel -S < %s | FileCheck %s
+;
+; Check that we mark multiple parallel loops correctly including the memory instructions.
+;
+; CHECK-DAG: %polly.loop_cond[[COuter:[0-9]*]] = icmp sle i64 %polly.indvar{{[0-9]*}}, 1022
+; CHECK-DAG: br i1 %polly.loop_cond[[COuter]], label %polly.loop_header{{[0-9]*}}, label %polly.loop_exit{{[0-9]*}}, !llvm.loop !0
+;
+; CHECK-DAG: %polly.loop_cond[[CInner:[0-9]*]] = icmp sle i64 %polly.indvar{{[0-9]*}}, 510
+; CHECK-DAG: br i1 %polly.loop_cond[[CInner]], label %polly.loop_header{{[0-9]*}}, label %polly.loop_exit{{[0-9]*}}, !llvm.loop !2
+;
+; CHECK-DAG: store i32 %p_tmp{{[0-9]*}}, i32* %p_arrayidx{{[0-9]*}}, !llvm.mem.parallel_loop_access !1
+;
+; CHECK: !0 = metadata !{metadata !0}
+; CHECK: !1 = metadata !{metadata !0, metadata !2}
+; CHECK: !2 = metadata !{metadata !2}
+;
+; void jd(int *A) {
+; for (int i = 0; i < 1024; i++)
+; for (int j = 0; j < 512; j++)
+; A[i * 512 + j] = i + j;
+; }
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @jd(i32* %A) {
+entry:
+ br label %for.cond
+
+for.cond: ; preds = %for.inc5, %entry
+ %indvars.iv3 = phi i64 [ %indvars.iv.next4, %for.inc5 ], [ 0, %entry ]
+ %exitcond6 = icmp ne i64 %indvars.iv3, 1024
+ br i1 %exitcond6, label %for.body, label %for.end7
+
+for.body: ; preds = %for.cond
+ br label %for.cond1
+
+for.cond1: ; preds = %for.inc, %for.body
+ %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %for.body ]
+ %exitcond = icmp ne i64 %indvars.iv, 512
+ br i1 %exitcond, label %for.body3, label %for.end
+
+for.body3: ; preds = %for.cond1
+ %tmp = add nsw i64 %indvars.iv3, %indvars.iv
+ %tmp7 = shl nsw i64 %indvars.iv3, 9
+ %tmp8 = add nsw i64 %tmp7, %indvars.iv
+ %arrayidx = getelementptr inbounds i32* %A, i64 %tmp8
+ %tmp9 = trunc i64 %tmp to i32
+ store i32 %tmp9, i32* %arrayidx, align 4
+ br label %for.inc
+
+for.inc: ; preds = %for.body3
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ br label %for.cond1
+
+for.end: ; preds = %for.cond1
+ br label %for.inc5
+
+for.inc5: ; preds = %for.end
+ %indvars.iv.next4 = add nuw nsw i64 %indvars.iv3, 1
+ br label %for.cond
+
+for.end7: ; preds = %for.cond
+ ret void
+}
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