[polly] r267707 - [FIX] Propagate execution domain of invariant loads
Johannes Doerfert via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 27 05:49:11 PDT 2016
Author: jdoerfert
Date: Wed Apr 27 07:49:11 2016
New Revision: 267707
URL: http://llvm.org/viewvc/llvm-project?rev=267707&view=rev
Log:
[FIX] Propagate execution domain of invariant loads
If the base pointer of an invariant load is is loaded conditionally, that
condition needs to hold for the invariant load too. The structure of the
program will imply this for domain constraints but not for imprecisions in
the modeling. To this end we will propagate the execution context of base
pointers during code generation and thus ensure the derived pointer does
not access an invalid base pointer.
Added:
polly/trunk/test/Isl/CodeGen/invariant_load_base_pointer_conditional_2.ll
Modified:
polly/trunk/include/polly/CodeGen/IslNodeBuilder.h
polly/trunk/include/polly/ScopInfo.h
polly/trunk/lib/Analysis/ScopInfo.cpp
polly/trunk/lib/CodeGen/IslNodeBuilder.cpp
Modified: polly/trunk/include/polly/CodeGen/IslNodeBuilder.h
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/include/polly/CodeGen/IslNodeBuilder.h?rev=267707&r1=267706&r2=267707&view=diff
==============================================================================
--- polly/trunk/include/polly/CodeGen/IslNodeBuilder.h (original)
+++ polly/trunk/include/polly/CodeGen/IslNodeBuilder.h Wed Apr 27 07:49:11 2016
@@ -247,7 +247,7 @@ protected:
/// to the required type.
///
/// @returns False, iff a problem occured and the load was not preloaded.
- bool preloadInvariantEquivClass(const InvariantEquivClassTy &IAClass);
+ bool preloadInvariantEquivClass(InvariantEquivClassTy &IAClass);
void createForVector(__isl_take isl_ast_node *For, int VectorWidth);
void createForSequential(__isl_take isl_ast_node *For, bool KnownParallel);
Modified: polly/trunk/include/polly/ScopInfo.h
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/include/polly/ScopInfo.h?rev=267707&r1=267706&r2=267707&view=diff
==============================================================================
--- polly/trunk/include/polly/ScopInfo.h (original)
+++ polly/trunk/include/polly/ScopInfo.h Wed Apr 27 07:49:11 2016
@@ -1895,10 +1895,10 @@ public:
inline unsigned getMaxLoopDepth() const { return MaxLoopDepth; }
/// @brief Return the invariant equivalence class for @p Val if any.
- const InvariantEquivClassTy *lookupInvariantEquivClass(Value *Val) const;
+ InvariantEquivClassTy *lookupInvariantEquivClass(Value *Val);
/// @brief Return the set of invariant accesses.
- const InvariantEquivClassesTy &getInvariantAccesses() const {
+ InvariantEquivClassesTy &getInvariantAccesses() {
return InvariantEquivClasses;
}
Modified: polly/trunk/lib/Analysis/ScopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Analysis/ScopInfo.cpp?rev=267707&r1=267706&r2=267707&view=diff
==============================================================================
--- polly/trunk/lib/Analysis/ScopInfo.cpp (original)
+++ polly/trunk/lib/Analysis/ScopInfo.cpp Wed Apr 27 07:49:11 2016
@@ -3221,7 +3221,7 @@ void Scop::simplifySCoP(bool RemoveIgnor
}
}
-const InvariantEquivClassTy *Scop::lookupInvariantEquivClass(Value *Val) const {
+InvariantEquivClassTy *Scop::lookupInvariantEquivClass(Value *Val) {
LoadInst *LInst = dyn_cast<LoadInst>(Val);
if (!LInst)
return nullptr;
Modified: polly/trunk/lib/CodeGen/IslNodeBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/CodeGen/IslNodeBuilder.cpp?rev=267707&r1=267706&r2=267707&view=diff
==============================================================================
--- polly/trunk/lib/CodeGen/IslNodeBuilder.cpp (original)
+++ polly/trunk/lib/CodeGen/IslNodeBuilder.cpp Wed Apr 27 07:49:11 2016
@@ -888,7 +888,7 @@ bool IslNodeBuilder::materializeValue(is
}
}
- if (const auto *IAClass = S.lookupInvariantEquivClass(Val)) {
+ if (auto *IAClass = S.lookupInvariantEquivClass(Val)) {
// Check if this invariant access class is empty, hence if we never
// actually added a loads instruction to it. In that case it has no
@@ -1035,7 +1035,7 @@ Value *IslNodeBuilder::preloadInvariantL
}
bool IslNodeBuilder::preloadInvariantEquivClass(
- const InvariantEquivClassTy &IAClass) {
+ InvariantEquivClassTy &IAClass) {
// For an equivalence class of invariant loads we pre-load the representing
// element with the unified execution context. However, we have to map all
// elements of the class to the one preloaded load as they are referenced
@@ -1059,18 +1059,26 @@ bool IslNodeBuilder::preloadInvariantEqu
if (!PreloadedPtrs.insert(PtrId).second)
return false;
+ // The exectution context of the IAClass.
+ isl_set *&ExecutionCtx = std::get<2>(IAClass);
+
// If the base pointer of this class is dependent on another one we have to
// make sure it was preloaded already.
auto *SAI = MA->getScopArrayInfo();
- if (const auto *BaseIAClass = S.lookupInvariantEquivClass(SAI->getBasePtr()))
+ if (auto *BaseIAClass = S.lookupInvariantEquivClass(SAI->getBasePtr())) {
if (!preloadInvariantEquivClass(*BaseIAClass))
return false;
+ // After we preloaded the BaseIAClass we adjusted the BaseExecutionCtx and
+ // we need to refine the ExecutionCtx.
+ isl_set *BaseExecutionCtx = isl_set_copy(std::get<2>(*BaseIAClass));
+ ExecutionCtx = isl_set_intersect(ExecutionCtx, BaseExecutionCtx);
+ }
+
Instruction *AccInst = MA->getAccessInstruction();
Type *AccInstTy = AccInst->getType();
- isl_set *Domain = isl_set_copy(std::get<2>(IAClass));
- Value *PreloadVal = preloadInvariantLoad(*MA, Domain);
+ Value *PreloadVal = preloadInvariantLoad(*MA, isl_set_copy(ExecutionCtx));
if (!PreloadVal)
return false;
@@ -1138,7 +1146,7 @@ bool IslNodeBuilder::preloadInvariantEqu
bool IslNodeBuilder::preloadInvariantLoads() {
- const auto &InvariantEquivClasses = S.getInvariantAccesses();
+ auto &InvariantEquivClasses = S.getInvariantAccesses();
if (InvariantEquivClasses.empty())
return true;
@@ -1147,7 +1155,7 @@ bool IslNodeBuilder::preloadInvariantLoa
PreLoadBB->setName("polly.preload.begin");
Builder.SetInsertPoint(&PreLoadBB->front());
- for (const auto &IAClass : InvariantEquivClasses)
+ for (auto &IAClass : InvariantEquivClasses)
if (!preloadInvariantEquivClass(IAClass))
return false;
Added: polly/trunk/test/Isl/CodeGen/invariant_load_base_pointer_conditional_2.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/Isl/CodeGen/invariant_load_base_pointer_conditional_2.ll?rev=267707&view=auto
==============================================================================
--- polly/trunk/test/Isl/CodeGen/invariant_load_base_pointer_conditional_2.ll (added)
+++ polly/trunk/test/Isl/CodeGen/invariant_load_base_pointer_conditional_2.ll Wed Apr 27 07:49:11 2016
@@ -0,0 +1,73 @@
+; RUN: opt %loadPolly -analyze -polly-scops < %s | FileCheck %s
+; RUN: opt %loadPolly -S -polly-codegen < %s | FileCheck %s --check-prefix=IR
+;
+; As (p + q) can overflow we have to check that we load from
+; I[p + q] only if it does not.
+;
+; CHECK: Invariant Accesses: {
+; CHECK-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
+; CHECK-NEXT: [N, p, q] -> { Stmt_for_body[i0] -> MemRef_I[p + q] };
+; CHECK-NEXT: Execution Context: [N, p, q] -> { : N > 0 and -2147483648 - p <= q <= 2147483647 - p }
+; CHECK-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
+; CHECK-NEXT: [N, p, q] -> { Stmt_for_body[i0] -> MemRef_tmp1[0] };
+; CHECK-NEXT: Execution Context: [N, p, q] -> { : N > 0 }
+; CHECK-NEXT: }
+;
+; IR: polly.preload.merge:
+; IR-NEXT: %polly.preload.tmp1.merge = phi i32* [ %polly.access.I.load, %polly.preload.exec ], [ null, %polly.preload.cond ]
+; IR-NEXT: store i32* %polly.preload.tmp1.merge, i32** %tmp1.preload.s2a
+; IR-NEXT: %12 = sext i32 %N to i64
+; IR-NEXT: %13 = icmp sge i64 %12, 1
+; IR-NEXT: %14 = sext i32 %q to i64
+; IR-NEXT: %15 = sext i32 %p to i64
+; IR-NEXT: %16 = add nsw i64 %15, %14
+; IR-NEXT: %17 = icmp sle i64 %16, 2147483647
+; IR-NEXT: %18 = and i1 %13, %17
+; IR-NEXT: %19 = sext i32 %q to i64
+; IR-NEXT: %20 = sext i32 %p to i64
+; IR-NEXT: %21 = add nsw i64 %20, %19
+; IR-NEXT: %22 = icmp sge i64 %21, -2147483648
+; IR-NEXT: %23 = and i1 %18, %22
+; IR-NEXT: br label %polly.preload.cond1
+;
+; IR: polly.preload.cond1:
+; IR-NEXT: br i1 %23
+;
+; IR: polly.preload.exec3:
+; IR-NEXT: %polly.access.polly.preload.tmp1.merge = getelementptr i32, i32* %polly.preload.tmp1.merge, i64 0
+; IR-NEXT: %polly.access.polly.preload.tmp1.merge.load = load i32, i32* %polly.access.polly.preload.tmp1.merge, align 4
+;
+; void f(int **I, int *A, int N, int p, int q) {
+; for (int i = 0; i < N; i++)
+; A[i] = *(I[p + q]);
+; }
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @f(i32** %I, i32* %A, i32 %N, i32 %p, i32 %q) {
+entry:
+ %tmp = sext i32 %N to i64
+ br label %for.cond
+
+for.cond: ; preds = %for.inc, %entry
+ %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
+ %cmp = icmp slt i64 %indvars.iv, %tmp
+ br i1 %cmp, label %for.body, label %for.end
+
+for.body: ; preds = %for.cond
+ %add = add i32 %p, %q
+ %idxprom = sext i32 %add to i64
+ %arrayidx = getelementptr inbounds i32*, i32** %I, i64 %idxprom
+ %tmp1 = load i32*, i32** %arrayidx, align 8
+ %tmp2 = load i32, i32* %tmp1, align 4
+ %arrayidx2 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
+ store i32 %tmp2, i32* %arrayidx2, align 4
+ br label %for.inc
+
+for.inc: ; preds = %for.body
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ br label %for.cond
+
+for.end: ; preds = %for.cond
+ ret void
+}
More information about the llvm-commits
mailing list