[LoopReroll] Ignore debug intrinsics

Originally, debug intrinsics and annotation intrinsics may prevent
the loop to be rerolled, now they are ignored.

Differential Revision: http://reviews.llvm.org/D13150

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248718 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/LoopRerollPass.cpp b/lib/Transforms/Scalar/LoopRerollPass.cpp
index f007d6855a4be13bf5c2245a147f90fbf3417e99..282071364dce80416b2c60edb0438df743b62f3a 100644 (file)
--- a/lib/Transforms/Scalar/LoopRerollPass.cpp
+++ b/lib/Transforms/Scalar/LoopRerollPass.cpp
@@ -993,6 +993,25 @@ bool LoopReroll::DAGRootTracker::instrDependsOn(Instruction *I,
   return false;
 }
 
   return false;
 }
 

+static bool isIgnorableInst(const Instruction *I) {
+  if (isa<DbgInfoIntrinsic>(I))
+    return true;
+  const IntrinsicInst* II = dyn_cast<IntrinsicInst>(I);
+  if (!II)
+    return false;
+  switch (II->getIntrinsicID()) {
+    default:
+      return false;
+    case llvm::Intrinsic::annotation:
+    case Intrinsic::ptr_annotation:
+    case Intrinsic::var_annotation:
+    // TODO: the following intrinsics may also be whitelisted:
+    //   lifetime_start, lifetime_end, invariant_start, invariant_end
+      return true;
+  }
+  return false;
+}
+

 bool LoopReroll::DAGRootTracker::validate(ReductionTracker &Reductions) {
   // We now need to check for equivalence of the use graph of each root with
   // that of the primary induction variable (excluding the roots). Our goal
 bool LoopReroll::DAGRootTracker::validate(ReductionTracker &Reductions) {
   // We now need to check for equivalence of the use graph of each root with
   // that of the primary induction variable (excluding the roots). Our goal


@@ -1026,7 +1045,7 @@ bool LoopReroll::DAGRootTracker::validate(ReductionTracker &Reductions) {
   // Make sure all instructions in the loop are in one and only one
   // set.
   for (auto &KV : Uses) {
   // Make sure all instructions in the loop are in one and only one
   // set.
   for (auto &KV : Uses) {

-    if (KV.second.count() != 1) {
+    if (KV.second.count() != 1 && !isIgnorableInst(KV.first)) {

       DEBUG(dbgs() << "LRR: Aborting - instruction is not used in 1 iteration: "
             << *KV.first << " (#uses=" << KV.second.count() << ")\n");
       return false;
       DEBUG(dbgs() << "LRR: Aborting - instruction is not used in 1 iteration: "
             << *KV.first << " (#uses=" << KV.second.count() << ")\n");
       return false;

diff --git a/test/Transforms/LoopReroll/reroll_with_dbg.ll b/test/Transforms/LoopReroll/reroll_with_dbg.ll
new file mode 100644 (file)
index 0000000..e239d0c
--- /dev/null
+++ b/test/Transforms/LoopReroll/reroll_with_dbg.ll
@@ -0,0 +1,139 @@
+;RUN: opt < %s -loop-reroll -S | FileCheck %s
+;void foo(float * restrict a, float * restrict b, int n) {
+;  for(int i = 0; i < n; i+=4) {
+;    a[i] = b[i];
+;    a[i+1] = b[i+1];
+;    a[i+2] = b[i+2];
+;    a[i+3] = b[i+3];
+;  }
+;}
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "armv4t--linux-gnueabi"
+
+; Function Attrs: nounwind
+define void @foo(float* noalias nocapture %a, float* noalias nocapture readonly %b, i32 %n) #0 {
+entry:
+;CHECK-LABEL: @foo
+
+  tail call void @llvm.dbg.value(metadata float* %a, i64 0, metadata !12, metadata !22), !dbg !23
+  tail call void @llvm.dbg.value(metadata float* %b, i64 0, metadata !13, metadata !22), !dbg !24
+  tail call void @llvm.dbg.value(metadata i32 %n, i64 0, metadata !14, metadata !22), !dbg !25
+  tail call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !15, metadata !22), !dbg !26
+  %cmp.30 = icmp sgt i32 %n, 0, !dbg !27
+  br i1 %cmp.30, label %for.body.preheader, label %for.cond.cleanup, !dbg !29
+
+for.body.preheader:                               ; preds = %entry
+  br label %for.body, !dbg !30
+
+for.cond.cleanup.loopexit:                        ; preds = %for.body
+  br label %for.cond.cleanup, !dbg !32
+
+for.cond.cleanup:                                 ; preds = %for.cond.cleanup.loopexit, %entry
+  ret void, !dbg !32
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+;CHECK: for.body:
+;CHECK: %indvar = phi i32 [ %indvar.next, %for.body ], [ 0, {{.*}} ]
+;CHECK: load
+;CHECK: store
+;CHECK-NOT: load
+;CHECK-NOT: store
+;CHECK: call void @llvm.dbg.value
+;CHECK: %indvar.next = add i32 %indvar, 1
+;CHECK: icmp eq i32 %indvar
+  %i.031 = phi i32 [ %add13, %for.body ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds float, float* %b, i32 %i.031, !dbg !30
+  %0 = bitcast float* %arrayidx to i32*, !dbg !30
+  %1 = load i32, i32* %0, align 4, !dbg !30, !tbaa !33
+  %arrayidx1 = getelementptr inbounds float, float* %a, i32 %i.031, !dbg !37
+  %2 = bitcast float* %arrayidx1 to i32*, !dbg !38
+  store i32 %1, i32* %2, align 4, !dbg !38, !tbaa !33
+  %add = or i32 %i.031, 1, !dbg !39
+  %arrayidx2 = getelementptr inbounds float, float* %b, i32 %add, !dbg !40
+  %3 = bitcast float* %arrayidx2 to i32*, !dbg !40
+  %4 = load i32, i32* %3, align 4, !dbg !40, !tbaa !33
+  %arrayidx4 = getelementptr inbounds float, float* %a, i32 %add, !dbg !41
+  %5 = bitcast float* %arrayidx4 to i32*, !dbg !42
+  store i32 %4, i32* %5, align 4, !dbg !42, !tbaa !33
+  %add5 = or i32 %i.031, 2, !dbg !43
+  %arrayidx6 = getelementptr inbounds float, float* %b, i32 %add5, !dbg !44
+  %6 = bitcast float* %arrayidx6 to i32*, !dbg !44
+  %7 = load i32, i32* %6, align 4, !dbg !44, !tbaa !33
+  %arrayidx8 = getelementptr inbounds float, float* %a, i32 %add5, !dbg !45
+  %8 = bitcast float* %arrayidx8 to i32*, !dbg !46
+  store i32 %7, i32* %8, align 4, !dbg !46, !tbaa !33
+  %add9 = or i32 %i.031, 3, !dbg !47
+  %arrayidx10 = getelementptr inbounds float, float* %b, i32 %add9, !dbg !48
+  %9 = bitcast float* %arrayidx10 to i32*, !dbg !48
+  %10 = load i32, i32* %9, align 4, !dbg !48, !tbaa !33
+  %arrayidx12 = getelementptr inbounds float, float* %a, i32 %add9, !dbg !49
+  %11 = bitcast float* %arrayidx12 to i32*, !dbg !50
+  store i32 %10, i32* %11, align 4, !dbg !50, !tbaa !33
+  %add13 = add nuw nsw i32 %i.031, 4, !dbg !51
+  tail call void @llvm.dbg.value(metadata i32 %add13, i64 0, metadata !15, metadata !22), !dbg !26
+  %cmp = icmp slt i32 %add13, %n, !dbg !27
+  br i1 %cmp, label %for.body, label %for.cond.cleanup.loopexit, !dbg !29
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
+
+attributes #0 = { nounwind "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="arm7tdmi" "target-features"="+strict-align" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!17, !18, !19, !20}
+!llvm.ident = !{!21}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (http://llvm.org/git/clang.git b1fbc23058e7fa1cdd954ab97ba84f1c549c9879) (http://llvm.org/git/llvm.git 054da58c5398a721d4dab7af63d7de8d7a1e1a1c)", isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "test.c", directory: "/home/weimingz/llvm-build/release/community-tip")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, function: void (float*, float*, i32)* @foo, variables: !11)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null, !7, !7, !10}
+!7 = !DIDerivedType(tag: DW_TAG_restrict_type, baseType: !8)
+!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 32, align: 32)
+!9 = !DIBasicType(name: "float", size: 32, align: 32, encoding: DW_ATE_float)
+!10 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!11 = !{!12, !13, !14, !15}
+!12 = !DILocalVariable(name: "a", arg: 1, scope: !4, file: !1, line: 1, type: !7)
+!13 = !DILocalVariable(name: "b", arg: 2, scope: !4, file: !1, line: 1, type: !7)
+!14 = !DILocalVariable(name: "n", arg: 3, scope: !4, file: !1, line: 1, type: !10)
+!15 = !DILocalVariable(name: "i", scope: !16, file: !1, line: 2, type: !10)
+!16 = distinct !DILexicalBlock(scope: !4, file: !1, line: 2, column: 3)
+!17 = !{i32 2, !"Dwarf Version", i32 4}
+!18 = !{i32 2, !"Debug Info Version", i32 3}
+!19 = !{i32 1, !"wchar_size", i32 4}
+!20 = !{i32 1, !"min_enum_size", i32 4}
+!21 = !{!"clang version 3.8.0 (http://llvm.org/git/clang.git b1fbc23058e7fa1cdd954ab97ba84f1c549c9879) (http://llvm.org/git/llvm.git 054da58c5398a721d4dab7af63d7de8d7a1e1a1c)"}
+!22 = !DIExpression()
+!23 = !DILocation(line: 1, column: 27, scope: !4)
+!24 = !DILocation(line: 1, column: 47, scope: !4)
+!25 = !DILocation(line: 1, column: 54, scope: !4)
+!26 = !DILocation(line: 2, column: 11, scope: !16)
+!27 = !DILocation(line: 2, column: 20, scope: !28)
+!28 = distinct !DILexicalBlock(scope: !16, file: !1, line: 2, column: 3)
+!29 = !DILocation(line: 2, column: 3, scope: !16)
+!30 = !DILocation(line: 3, column: 12, scope: !31)
+!31 = distinct !DILexicalBlock(scope: !28, file: !1, line: 2, column: 31)
+!32 = !DILocation(line: 8, column: 1, scope: !4)
+!33 = !{!34, !34, i64 0}
+!34 = !{!"float", !35, i64 0}
+!35 = !{!"omnipotent char", !36, i64 0}
+!36 = !{!"Simple C/C++ TBAA"}
+!37 = !DILocation(line: 3, column: 5, scope: !31)
+!38 = !DILocation(line: 3, column: 10, scope: !31)
+!39 = !DILocation(line: 4, column: 17, scope: !31)
+!40 = !DILocation(line: 4, column: 14, scope: !31)
+!41 = !DILocation(line: 4, column: 5, scope: !31)
+!42 = !DILocation(line: 4, column: 12, scope: !31)
+!43 = !DILocation(line: 5, column: 17, scope: !31)
+!44 = !DILocation(line: 5, column: 14, scope: !31)
+!45 = !DILocation(line: 5, column: 5, scope: !31)
+!46 = !DILocation(line: 5, column: 12, scope: !31)
+!47 = !DILocation(line: 6, column: 17, scope: !31)
+!48 = !DILocation(line: 6, column: 14, scope: !31)
+!49 = !DILocation(line: 6, column: 5, scope: !31)
+!50 = !DILocation(line: 6, column: 12, scope: !31)
+!51 = !DILocation(line: 2, column: 26, scope: !28)