From 0ba164bbcba92404f2f8df7ee4129f2b059776a1 Mon Sep 17 00:00:00 2001 From: Adam Nemet Date: Thu, 28 Apr 2016 23:08:32 +0000 Subject: [PATCH] [LoopDist] Emit optimization remarks (-Rpass*) I closely followed the precedents set by the vectorizer: * With -Rpass-missed, the loop is reported with further details pointing to -Rpass--analysis. * -Rpass-analysis reports the details why distribution has failed. * Regardless of -Rpass*, when distribution fails for a loop where distribution was forced with the pragma, a warning is produced according to -Wpass-failed. In this case the analysis info is also printed even without -Rpass-analysis. llvm-svn: 267952 --- llvm/lib/Transforms/Scalar/LoopDistribute.cpp | 25 ++++ .../Transforms/LoopDistribute/diagnostics.ll | 118 ++++++++++++++++++ 2 files changed, 143 insertions(+) create mode 100644 llvm/test/Transforms/LoopDistribute/diagnostics.ll diff --git a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp index 1dcfcda31a8e..3b484f31acc0 100644 --- a/llvm/lib/Transforms/Scalar/LoopDistribute.cpp +++ b/llvm/lib/Transforms/Scalar/LoopDistribute.cpp @@ -28,6 +28,7 @@ #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/LoopAccessAnalysis.h" #include "llvm/Analysis/LoopInfo.h" +#include "llvm/IR/DiagnosticInfo.h" #include "llvm/IR/Dominators.h" #include "llvm/Pass.h" #include "llvm/Support/CommandLine.h" @@ -745,7 +746,31 @@ public: /// \brief Provide diagnostics then \return with false. bool fail(llvm::StringRef Message) { + Function *F = L->getHeader()->getParent(); + LLVMContext &Ctx = F->getContext(); + bool Forced = isForced().getValueOr(false); + DEBUG(dbgs() << "Skipping; " << Message << "\n"); + + // With Rpass-missed report that distribution failed. + emitOptimizationRemarkMissed( + Ctx, LDIST_NAME, *F, L->getStartLoc(), + "loop not distributed: use -Rpass-analysis=loop-distribute for more " + "info"); + + // With Rpass-analysis report why. This is on by default if distribution + // was requested explicitly. + emitOptimizationRemarkAnalysis( + Ctx, Forced ? DiagnosticInfo::AlwaysPrint : LDIST_NAME, *F, + L->getStartLoc(), Twine("loop not distributed: ") + Message); + + // Also issue a warning if distribution was requested explicitly but it + // failed. + if (Forced) + Ctx.diagnose(DiagnosticInfoOptimizationFailure( + *F, L->getStartLoc(), "loop not disributed: failed " + "explicitly specified loop distribution")); + return false; } diff --git a/llvm/test/Transforms/LoopDistribute/diagnostics.ll b/llvm/test/Transforms/LoopDistribute/diagnostics.ll new file mode 100644 index 000000000000..14b7d22d3da3 --- /dev/null +++ b/llvm/test/Transforms/LoopDistribute/diagnostics.ll @@ -0,0 +1,118 @@ +; RUN: opt -loop-distribute -S < %s 2>&1 \ +; RUN: | FileCheck %s --check-prefix=ALWAYS --check-prefix=NO_REMARKS +; RUN: opt -loop-distribute -S -pass-remarks-missed=loop-distribute < %s 2>&1 \ +; RUN: | FileCheck %s --check-prefix=ALWAYS --check-prefix=MISSED_REMARKS +; RUN: opt -loop-distribute -S -pass-remarks-analysis=loop-distribute < %s 2>&1 \ +; RUN: | FileCheck %s --check-prefix=ALWAYS --check-prefix=ANALYSIS_REMARKS + +; This is the input program: +; +; 1 void forced (char *A, char *B, char *C, int N) { +; 2 #pragma clang loop distribute(enable) +; 3 for(int i = 0; i < N; i++) { +; 4 A[i] = B[i] * C[i]; +; 5 } +; 6 } +; 7 +; 8 void not_forced (char *A, char *B, char *C, int N) { +; 9 for(int i = 0; i < N; i++) { +; 10 A[i] = B[i] * C[i]; +; 11 } +; 12 } + +target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.11.0" + +; MISSED_REMARKS: remark: /tmp/t.c:3:3: loop not distributed: use -Rpass-analysis=loop-distribute for more info +; ALWAYS: remark: /tmp/t.c:3:3: loop not distributed: memory operations are safe for vectorization +; ALWAYS: warning: /tmp/t.c:3:3: loop not disributed: failed explicitly specified loop distribution + +define void @forced(i8* %A, i8* %B, i8* %C, i32 %N) !dbg !7 { +entry: + %cmp12 = icmp sgt i32 %N, 0, !dbg !9 + br i1 %cmp12, label %ph, label %for.cond.cleanup, !dbg !10 + +ph: + br label %for.body + +for.body: + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %ph ] + %arrayidx = getelementptr inbounds i8, i8* %B, i64 %indvars.iv, !dbg !12 + %0 = load i8, i8* %arrayidx, align 1, !dbg !12, !tbaa !13 + %arrayidx2 = getelementptr inbounds i8, i8* %C, i64 %indvars.iv, !dbg !16 + %1 = load i8, i8* %arrayidx2, align 1, !dbg !16, !tbaa !13 + %mul = mul i8 %1, %0, !dbg !17 + %arrayidx6 = getelementptr inbounds i8, i8* %A, i64 %indvars.iv, !dbg !18 + store i8 %mul, i8* %arrayidx6, align 1, !dbg !19, !tbaa !13 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !10 + %lftr.wideiv = trunc i64 %indvars.iv.next to i32, !dbg !10 + %exitcond = icmp eq i32 %lftr.wideiv, %N, !dbg !10 + br i1 %exitcond, label %for.cond.cleanup, label %for.body, !dbg !10, !llvm.loop !20 + +for.cond.cleanup: + ret void, !dbg !11 +} + +; NO_REMARKS-NOT: remark: /tmp/t.c:9:3: loop not distributed: memory operations are safe for vectorization +; MISSED_REMARKS: remark: /tmp/t.c:9:3: loop not distributed: use -Rpass-analysis=loop-distribute for more info +; ANALYSIS_REMARKS: remark: /tmp/t.c:9:3: loop not distributed: memory operations are safe for vectorization +; ALWAYS-NOT: warning: /tmp/t.c:9:3: loop not disributed: failed explicitly specified loop distribution + +define void @not_forced(i8* %A, i8* %B, i8* %C, i32 %N) !dbg !22 { +entry: + %cmp12 = icmp sgt i32 %N, 0, !dbg !23 + br i1 %cmp12, label %ph, label %for.cond.cleanup, !dbg !24 + +ph: + br label %for.body + +for.body: + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %ph ] + %arrayidx = getelementptr inbounds i8, i8* %B, i64 %indvars.iv, !dbg !26 + %0 = load i8, i8* %arrayidx, align 1, !dbg !26, !tbaa !13 + %arrayidx2 = getelementptr inbounds i8, i8* %C, i64 %indvars.iv, !dbg !27 + %1 = load i8, i8* %arrayidx2, align 1, !dbg !27, !tbaa !13 + %mul = mul i8 %1, %0, !dbg !28 + %arrayidx6 = getelementptr inbounds i8, i8* %A, i64 %indvars.iv, !dbg !29 + store i8 %mul, i8* %arrayidx6, align 1, !dbg !30, !tbaa !13 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !24 + %lftr.wideiv = trunc i64 %indvars.iv.next to i32, !dbg !24 + %exitcond = icmp eq i32 %lftr.wideiv, %N, !dbg !24 + br i1 %exitcond, label %for.cond.cleanup, label %for.body, !dbg !24 + +for.cond.cleanup: + ret void, !dbg !25 +} + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.9.0 (trunk 267633) (llvm/trunk 267675)", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2) +!1 = !DIFile(filename: "/tmp/t.c", directory: "/tmp") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 2} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!7 = distinct !DISubprogram(name: "forced", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !2) +!8 = !DISubroutineType(types: !2) +!9 = !DILocation(line: 3, column: 20, scope: !7) +!10 = !DILocation(line: 3, column: 3, scope: !7) +!11 = !DILocation(line: 6, column: 1, scope: !7) +!12 = !DILocation(line: 4, column: 12, scope: !7) +!13 = !{!14, !14, i64 0} +!14 = !{!"omnipotent char", !15, i64 0} +!15 = !{!"Simple C/C++ TBAA"} +!16 = !DILocation(line: 4, column: 19, scope: !7) +!17 = !DILocation(line: 4, column: 17, scope: !7) +!18 = !DILocation(line: 4, column: 5, scope: !7) +!19 = !DILocation(line: 4, column: 10, scope: !7) +!20 = distinct !{!20, !21} +!21 = !{!"llvm.loop.distribute.enable", i1 true} +!22 = distinct !DISubprogram(name: "not_forced", scope: !1, file: !1, line: 8, type: !8, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !2) +!23 = !DILocation(line: 9, column: 20, scope: !22) +!24 = !DILocation(line: 9, column: 3, scope: !22) +!25 = !DILocation(line: 12, column: 1, scope: !22) +!26 = !DILocation(line: 10, column: 12, scope: !22) +!27 = !DILocation(line: 10, column: 19, scope: !22) +!28 = !DILocation(line: 10, column: 17, scope: !22) +!29 = !DILocation(line: 10, column: 5, scope: !22) +!30 = !DILocation(line: 10, column: 10, scope: !22)