Reset the TopRPTracker's position in ScheduleDAGMILive::initQueues

ScheduleDAGMI::initQueues changes the RegionBegin to the first non-debug
instruction. Since it does not track register pressure, it does not affect
any RP trackers. ScheduleDAGMILive inherits initQueues from ScheduleDAGMI,
and it does reset the TopTPTracker in its schedule method. Any derived,
target-specific scheduler will need to do it as well, but the TopRPTracker
is only exposed as a "const" object to derived classes. Without the ability
to modify the tracker directly, this leaves a derived scheduler with a
potential of having the TopRPTracker out-of-sync with the CurrentTop.

The symptom of the problem:
  void llvm::ScheduleDAGMILive::scheduleMI(llvm::SUnit *, bool):
  Assertion `TopRPTracker.getPos() == CurrentTop && "out of sync"' failed.

Differential Revision: http://reviews.llvm.org/D19438

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267918 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/MachineScheduler.h b/include/llvm/CodeGen/MachineScheduler.h
index 64ea042..671db3b 100644 (file)
--- a/include/llvm/CodeGen/MachineScheduler.h
+++ b/include/llvm/CodeGen/MachineScheduler.h
@@ -461,6 +461,10 @@ protected:
   /// bottom of the DAG region without covereing any unscheduled instruction.
   void buildDAGWithRegPressure();
 
+  /// Release ExitSU predecessors and setup scheduler queues. Re-position
+  /// the Top RP tracker in case the region beginning has changed.
+  void initQueues(ArrayRef<SUnit*> TopRoots, ArrayRef<SUnit*> BotRoots);
+
   /// Move an instruction and update register pressure.
   void scheduleMI(SUnit *SU, bool IsTopNode);
 

diff --git a/lib/CodeGen/MachineScheduler.cpp b/lib/CodeGen/MachineScheduler.cpp
index 6124b03..da21cfc 100644 (file)
--- a/lib/CodeGen/MachineScheduler.cpp
+++ b/lib/CodeGen/MachineScheduler.cpp
@@ -1113,11 +1113,6 @@ void ScheduleDAGMILive::schedule() {
   // Initialize ready queues now that the DAG and priority data are finalized.
   initQueues(TopRoots, BotRoots);
 
-  if (ShouldTrackPressure) {
-    assert(TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker");
-    TopRPTracker.setPos(CurrentTop);
-  }
-
   bool IsTopNode = false;
   while (true) {
     DEBUG(dbgs() << "** ScheduleDAGMILive::schedule picking next node\n");
@@ -1275,6 +1270,17 @@ unsigned ScheduleDAGMILive::computeCyclicCriticalPath() {
   return MaxCyclicLatency;
 }
 
+/// Release ExitSU predecessors and setup scheduler queues. Re-position
+/// the Top RP tracker in case the region beginning has changed.
+void ScheduleDAGMILive::initQueues(ArrayRef<SUnit*> TopRoots,
+                                   ArrayRef<SUnit*> BotRoots) {
+  ScheduleDAGMI::initQueues(TopRoots, BotRoots);
+  if (ShouldTrackPressure) {
+    assert(TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker");
+    TopRPTracker.setPos(CurrentTop);
+  }
+}
+
 /// Move an instruction and update register pressure.
 void ScheduleDAGMILive::scheduleMI(SUnit *SU, bool IsTopNode) {
   // Move the instruction to its new location in the instruction stream.

diff --git a/test/CodeGen/Hexagon/misched-top-rptracker-sync.ll b/test/CodeGen/Hexagon/misched-top-rptracker-sync.ll
new file mode 100644 (file)
index 0000000..5fe16db
--- /dev/null
+++ b/test/CodeGen/Hexagon/misched-top-rptracker-sync.ll
@@ -0,0 +1,151 @@
+; RUN: llc -march=hexagon < %s
+; REQUIRES: asserts
+
+; Check that we no longer get this error:
+; void llvm::ScheduleDAGMILive::scheduleMI(llvm::SUnit *, bool):
+; Assertion `TopRPTracker.getPos() == CurrentTop && "out of sync"' failed.
+
+target triple = "hexagon"
+
+%struct.A = type { %struct.B*, %struct.B* }
+%struct.B = type { i8*, %struct.B*, %struct.B* }
+
+@.str.4 = external hidden unnamed_addr constant [41 x i8], align 1
+@__func__.fred = external hidden unnamed_addr constant [16 x i8], align 1
+@.str.5 = external hidden unnamed_addr constant [43 x i8], align 1
+
+; Function Attrs: nounwind
+declare void @_Assert(i8*, i8*) #0
+
+; Function Attrs: nounwind
+define void @fred(%struct.A* %pA, %struct.B* %p) #0 !dbg !6 {
+entry:
+  tail call void @llvm.dbg.value(metadata %struct.A* %pA, i64 0, metadata !26, metadata !28), !dbg !29
+  tail call void @llvm.dbg.value(metadata %struct.B* %p, i64 0, metadata !27, metadata !28), !dbg !30
+  %cmp = icmp eq %struct.B* %p, null, !dbg !31
+  br i1 %cmp, label %cond.false, label %cond.end, !dbg !31
+
+cond.false:                                       ; preds = %entry
+  tail call void @_Assert(i8* getelementptr inbounds ([41 x i8], [41 x i8]* @.str.4, i32 0, i32 0), i8* getelementptr inbounds ([16 x i8], [16 x i8]* @__func__.fred, i32 0, i32 0)) #0, !dbg !32
+  br label %cond.end, !dbg !32
+
+cond.end:                                         ; preds = %cond.false, %entry
+  %cmp1 = icmp eq %struct.A* %pA, null, !dbg !34
+  br i1 %cmp1, label %cond.false3, label %cond.end4, !dbg !34
+
+cond.false3:                                      ; preds = %cond.end
+  tail call void @_Assert(i8* getelementptr inbounds ([43 x i8], [43 x i8]* @.str.5, i32 0, i32 0), i8* getelementptr inbounds ([16 x i8], [16 x i8]* @__func__.fred, i32 0, i32 0)) #0, !dbg !35
+  br label %cond.end4, !dbg !35
+
+cond.end4:                                        ; preds = %cond.false3, %cond.end
+  %p2 = getelementptr inbounds %struct.A, %struct.A* %pA, i32 0, i32 0, !dbg !36
+  %0 = load %struct.B*, %struct.B** %p2, align 4, !dbg !38, !tbaa !39
+  %cmp5 = icmp eq %struct.B* %0, null, !dbg !44
+  br i1 %cmp5, label %if.then, label %if.end, !dbg !45
+
+if.then:                                          ; preds = %cond.end4
+  %p1 = getelementptr inbounds %struct.A, %struct.A* %pA, i32 0, i32 1, !dbg !46
+  store %struct.B* %p, %struct.B** %p1, align 4, !dbg !48, !tbaa !49
+  store %struct.B* %p, %struct.B** %p2, align 4, !dbg !50, !tbaa !39
+  %p4 = getelementptr inbounds %struct.B, %struct.B* %p, i32 0, i32 1, !dbg !51
+  store %struct.B* null, %struct.B** %p4, align 4, !dbg !52, !tbaa !53
+  %p5 = getelementptr inbounds %struct.B, %struct.B* %p, i32 0, i32 2, !dbg !55
+  store %struct.B* null, %struct.B** %p5, align 4, !dbg !56, !tbaa !57
+  br label %return, !dbg !58
+
+if.end:                                           ; preds = %cond.end4
+  %1 = ptrtoint %struct.B* %0 to i32, !dbg !59
+  %p57 = getelementptr inbounds %struct.B, %struct.B* %p, i32 0, i32 2, !dbg !60
+  store %struct.B* null, %struct.B** %p57, align 4, !dbg !61, !tbaa !57
+  %p49 = getelementptr inbounds %struct.B, %struct.B* %p, i32 0, i32 1, !dbg !62
+  %2 = bitcast %struct.B** %p49 to i32*, !dbg !63
+  store i32 %1, i32* %2, align 4, !dbg !63, !tbaa !53
+  %p511 = getelementptr inbounds %struct.B, %struct.B* %0, i32 0, i32 2, !dbg !64
+  store %struct.B* %p, %struct.B** %p511, align 4, !dbg !65, !tbaa !57
+  store %struct.B* %p, %struct.B** %p2, align 4, !dbg !66, !tbaa !39
+  br label %return, !dbg !67
+
+return:                                           ; preds = %if.end, %if.then
+  ret void, !dbg !68
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
+
+attributes #0 = { nounwind }
+attributes #1 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+!llvm.ident = !{!5}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.9.0 (http://llvm.org/git/clang.git 4b380bc1db8b0c72bdbdaf0e4697b1a84100a369) (http://llvm.org/git/llvm.git 6217a62bc009d55e160dbb694f2e94a22c80809f)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "bug.c", directory: "/")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!"clang version 3.9.0 (http://llvm.org/git/clang.git 4b380bc1db8b0c72bdbdaf0e4697b1a84100a369) (http://llvm.org/git/llvm.git 6217a62bc009d55e160dbb694f2e94a22c80809f)"}
+!6 = distinct !DISubprogram(name: "fred", scope: !1, file: !1, line: 138, type: !7, isLocal: false, isDefinition: true, scopeLine: 139, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !25)
+!7 = !DISubroutineType(types: !8)
+!8 = !{null, !9, !15}
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 32, align: 32)
+!10 = !DIDerivedType(tag: DW_TAG_typedef, name: "A", file: !11, line: 57, baseType: !12)
+!11 = !DIFile(filename: "bug.h", directory: "/")
+!12 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !11, line: 54, size: 64, align: 32, elements: !13)
+!13 = !{!14, !24}
+!14 = !DIDerivedType(tag: DW_TAG_member, name: "p2", scope: !12, file: !11, line: 55, baseType: !15, size: 32, align: 32)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 32, align: 32)
+!16 = !DIDerivedType(tag: DW_TAG_typedef, name: "B", file: !11, line: 50, baseType: !17)
+!17 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "B", file: !11, line: 45, size: 96, align: 32, elements: !18)
+!18 = !{!19, !21, !23}
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "p3", scope: !17, file: !11, line: 47, baseType: !20, size: 32, align: 32)
+!20 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 32, align: 32)
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "p4", scope: !17, file: !11, line: 48, baseType: !22, size: 32, align: 32, offset: 32)
+!22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !17, size: 32, align: 32)
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "p5", scope: !17, file: !11, line: 49, baseType: !22, size: 32, align: 32, offset: 64)
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "p1", scope: !12, file: !11, line: 56, baseType: !15, size: 32, align: 32, offset: 32)
+!25 = !{!26, !27}
+!26 = !DILocalVariable(name: "pA", arg: 1, scope: !6, file: !1, line: 138, type: !9)
+!27 = !DILocalVariable(name: "p", arg: 2, scope: !6, file: !1, line: 138, type: !15)
+!28 = !DIExpression()
+!29 = !DILocation(line: 138, column: 34, scope: !6)
+!30 = !DILocation(line: 138, column: 57, scope: !6)
+!31 = !DILocation(line: 140, column: 5, scope: !6)
+!32 = !DILocation(line: 140, column: 5, scope: !33)
+!33 = !DILexicalBlockFile(scope: !6, file: !1, discriminator: 2)
+!34 = !DILocation(line: 141, column: 5, scope: !6)
+!35 = !DILocation(line: 141, column: 5, scope: !33)
+!36 = !DILocation(line: 143, column: 30, scope: !37)
+!37 = distinct !DILexicalBlock(scope: !6, file: !1, line: 143, column: 9)
+!38 = !DILocation(line: 155, column: 18, scope: !6)
+!39 = !{!40, !41, i64 0}
+!40 = !{!"", !41, i64 0, !41, i64 4}
+!41 = !{!"any pointer", !42, i64 0}
+!42 = !{!"omnipotent char", !43, i64 0}
+!43 = !{!"Simple C/C++ TBAA"}
+!44 = !DILocation(line: 143, column: 14, scope: !37)
+!45 = !DILocation(line: 143, column: 9, scope: !6)
+!46 = !DILocation(line: 146, column: 26, scope: !47)
+!47 = distinct !DILexicalBlock(scope: !37, file: !1, line: 143, column: 41)
+!48 = !DILocation(line: 146, column: 36, scope: !47)
+!49 = !{!40, !41, i64 4}
+!50 = !DILocation(line: 145, column: 32, scope: !47)
+!51 = !DILocation(line: 147, column: 20, scope: !47)
+!52 = !DILocation(line: 147, column: 29, scope: !47)
+!53 = !{!54, !41, i64 4}
+!54 = !{!"B", !41, i64 0, !41, i64 4, !41, i64 8}
+!55 = !DILocation(line: 148, column: 20, scope: !47)
+!56 = !DILocation(line: 148, column: 29, scope: !47)
+!57 = !{!54, !41, i64 8}
+!58 = !DILocation(line: 149, column: 9, scope: !47)
+!59 = !DILocation(line: 154, column: 41, scope: !6)
+!60 = !DILocation(line: 153, column: 16, scope: !6)
+!61 = !DILocation(line: 153, column: 25, scope: !6)
+!62 = !DILocation(line: 154, column: 16, scope: !6)
+!63 = !DILocation(line: 154, column: 26, scope: !6)
+!64 = !DILocation(line: 155, column: 29, scope: !6)
+!65 = !DILocation(line: 155, column: 39, scope: !6)
+!66 = !DILocation(line: 156, column: 28, scope: !6)
+!67 = !DILocation(line: 157, column: 1, scope: !6)
+!68 = !DILocation(line: 157, column: 1, scope: !69)
+!69 = !DILexicalBlockFile(scope: !6, file: !1, discriminator: 1)