From 9dd42ee7c18a5a13ea40ea31654d01ea26d8d014 Mon Sep 17 00:00:00 2001 From: Johannes Doerfert Date: Thu, 25 Feb 2016 14:06:11 +0000 Subject: [PATCH] Try to build alias checks even when non-affine accesses are allowed From now on we bail only if a non-trivial alias group contains a non-affine access, not when we discover aliasing and non-affine accesses are allowed. llvm-svn: 261863 --- polly/lib/Analysis/ScopDetection.cpp | 6 --- polly/lib/Analysis/ScopInfo.cpp | 14 ++++++ polly/test/Isl/Ast/alias_simple_2.ll | 2 + .../aliasing_with_non_affine_access.ll | 49 +++++++++++++++++++ 4 files changed, 65 insertions(+), 6 deletions(-) create mode 100644 polly/test/ScopInfo/aliasing_with_non_affine_access.ll diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp index c16d9fb20b21..d3ac0fc567b2 100644 --- a/polly/lib/Analysis/ScopDetection.cpp +++ b/polly/lib/Analysis/ScopDetection.cpp @@ -232,12 +232,6 @@ ScopDetection::ScopDetection() : FunctionPass(ID) { PollyUseRuntimeAliasChecks = false; return; } - - if (AllowNonAffine) { - DEBUG(errs() << "WARNING: We disable runtime alias checks as non affine " - "accesses are enabled.\n"); - PollyUseRuntimeAliasChecks = false; - } } template diff --git a/polly/lib/Analysis/ScopInfo.cpp b/polly/lib/Analysis/ScopInfo.cpp index dc18d618b3bc..e549ba213279 100644 --- a/polly/lib/Analysis/ScopInfo.cpp +++ b/polly/lib/Analysis/ScopInfo.cpp @@ -2689,6 +2689,20 @@ bool Scop::buildAliasGroups(AliasAnalysis &AA) { continue; } + // Check if we have non-affine accesses left, if so bail out as we cannot + // generate a good access range yet. + for (auto *MA : AG) + if (!MA->isAffine()) { + invalidate(ALIASING, MA->getAccessInstruction()->getDebugLoc()); + return false; + } + for (auto &ReadOnlyPair : ReadOnlyPairs) + for (auto *MA : ReadOnlyPair.second) + if (!MA->isAffine()) { + invalidate(ALIASING, MA->getAccessInstruction()->getDebugLoc()); + return false; + } + // Calculate minimal and maximal accesses for non read only accesses. MinMaxAliasGroups.emplace_back(); MinMaxVectorPairTy &pair = MinMaxAliasGroups.back(); diff --git a/polly/test/Isl/Ast/alias_simple_2.ll b/polly/test/Isl/Ast/alias_simple_2.ll index 155ad2607e4f..42f6bb475156 100644 --- a/polly/test/Isl/Ast/alias_simple_2.ll +++ b/polly/test/Isl/Ast/alias_simple_2.ll @@ -3,6 +3,7 @@ ; RUN: opt %loadPolly -polly-ast -analyze -disable-basicaa -tbaa < %s | FileCheck %s --check-prefix=TBAA ; RUN: opt %loadPolly -polly-ast -analyze -disable-basicaa -scev-aa < %s | FileCheck %s --check-prefix=SCEV ; RUN: opt %loadPolly -polly-ast -analyze -disable-basicaa -globals-aa < %s | FileCheck %s --check-prefix=GLOB +; RUN: opt %loadPolly -polly-ast -analyze -disable-basicaa -globals-aa -polly-allow-nonaffine < %s | FileCheck %s --check-prefix=NONAFFINE ; ; int A[1024], B[1024]; ; @@ -17,6 +18,7 @@ ; TBAA: if (1 && (&MemRef_B[N] <= &MemRef_A[0] || &MemRef_A[N] <= &MemRef_B[0])) ; SCEV: if (1 && (&MemRef_B[N] <= &MemRef_A[0] || &MemRef_A[N] <= &MemRef_B[0])) ; GLOB: if (1 && (&MemRef_B[N] <= &MemRef_A[0] || &MemRef_A[N] <= &MemRef_B[0])) +; NONAFFINE: if (1 && (&MemRef_B[N] <= &MemRef_A[0] || &MemRef_A[N] <= &MemRef_B[0])) ; target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" diff --git a/polly/test/ScopInfo/aliasing_with_non_affine_access.ll b/polly/test/ScopInfo/aliasing_with_non_affine_access.ll new file mode 100644 index 000000000000..db719219e214 --- /dev/null +++ b/polly/test/ScopInfo/aliasing_with_non_affine_access.ll @@ -0,0 +1,49 @@ +; RUN: opt %loadPolly -analyze -polly-scops < %s | FileCheck %s +; RUN: opt %loadPolly -analyze -polly-scops -pass-remarks-analysis="polly-scops" 2>&1 < %s | FileCheck %s --check-prefix=REMARK +; +; This test case has a non-affine access (the memset call) that aliases with +; other accesses. Thus, we bail out. +; +; CHECK-NOT: Statements +; +; REMARK: remark: :0:0: SCoP begins here. +; REMARK-NEXT: remark: :0:0: Possibly aliasing pointer, use restrict keyword. +; REMARK-NEXT: remark: :0:0: Possibly aliasing pointer, use restrict keyword. +; REMARK-NEXT: remark: :0:0: No-aliasing assumption: { : 1 = 0 } +; REMARK-NEXT: remark: :0:0: SCoP ends here but was dismissed. +; +; ModuleID = 'bugpoint-reduced-simplified.bc' +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" + +%struct.info = type { i32, %struct.ctr*, i32, %struct.ord*, %struct.ctr*, i32, i8*, i32, i32, double } +%struct.ctr = type { i32, i8, i8, i32 } +%struct.ord = type { i32, i8 } + +; Function Attrs: argmemonly nounwind +declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) #0 + +; Function Attrs: nounwind uwtable +define void @bestVirtualIndex(%struct.info** %ppIdxInfo) { +entry: + %0 = load %struct.info*, %struct.info** %ppIdxInfo, align 8 + br label %if.end125 + +if.end125: ; preds = %entry + %1 = load %struct.ctr*, %struct.ctr** undef, align 8 + br label %for.end143 + +for.end143: ; preds = %if.end125 + %2 = bitcast %struct.ctr* %1 to i8* + tail call void @llvm.memset.p0i8.i64(i8* %2, i8 0, i64 32, i32 4, i1 false) + %needToFreeIdxStr = getelementptr inbounds %struct.info, %struct.info* %0, i64 0, i32 7 + %3 = load i32, i32* %needToFreeIdxStr, align 8 + br i1 false, label %if.end149, label %if.then148 + +if.then148: ; preds = %for.end143 + br label %if.end149 + +if.end149: ; preds = %if.then148, %for.end143 + unreachable +} + +attributes #0 = { argmemonly nounwind }