[llvm] r343007 - [WebAssembly] Move/clone DBG_VALUE during WebAssemblyRegStackify pass

Yury Delendik via llvm-commits llvm-commits at lists.llvm.org
Tue Sep 25 11:59:34 PDT 2018


Author: yurydelendik
Date: Tue Sep 25 11:59:34 2018
New Revision: 343007

URL: http://llvm.org/viewvc/llvm-project?rev=343007&view=rev
Log:
[WebAssembly] Move/clone DBG_VALUE during WebAssemblyRegStackify pass

Summary:
The MoveForSingleUse or MoveAndTeeForMultiUse functions move wasm instructions,
however DBG_VALUE stay unchanged -- moving or cloning these.

Reviewers: dschuff

Reviewed By: dschuff

Subscribers: mattd, MatzeB, dschuff, sbc100, jgravelle-google, aheejin, sunfish, llvm-commits, aardappel

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D49034

Added:
    llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move-2.ll
    llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move.ll
Modified:
    llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp

Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp?rev=343007&r1=343006&r2=343007&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp Tue Sep 25 11:59:34 2018
@@ -25,6 +25,7 @@
 #include "WebAssemblyMachineFunctionInfo.h"
 #include "WebAssemblySubtarget.h"
 #include "WebAssemblyUtilities.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/CodeGen/LiveIntervals.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
@@ -465,6 +466,27 @@ static void ShrinkToUses(LiveInterval &L
   }
 }
 
+static void MoveDebugValues(unsigned Reg, MachineInstr *Insert,
+                            MachineBasicBlock &MBB, MachineRegisterInfo &MRI) {
+  for (auto &Op : MRI.reg_operands(Reg)) {
+    MachineInstr *MI = Op.getParent();
+    assert(MI != nullptr);
+    if (MI->isDebugValue() && MI->getParent() == &MBB)
+      MBB.splice(Insert, &MBB, MI);
+  }
+}
+
+static void UpdateDebugValuesReg(unsigned Reg, unsigned NewReg,
+                                 MachineBasicBlock &MBB,
+                                 MachineRegisterInfo &MRI) {
+  for (auto &Op : MRI.reg_operands(Reg)) {
+    MachineInstr *MI = Op.getParent();
+    assert(MI != nullptr);
+    if (MI->isDebugValue() && MI->getParent() == &MBB)
+      Op.setReg(NewReg);
+  }
+}
+
 /// A single-use def in the same block with no intervening memory or register
 /// dependencies; move the def down and nest it with the current instruction.
 static MachineInstr *MoveForSingleUse(unsigned Reg, MachineOperand &Op,
@@ -475,6 +497,7 @@ static MachineInstr *MoveForSingleUse(un
   LLVM_DEBUG(dbgs() << "Move for single use: "; Def->dump());
 
   MBB.splice(Insert, &MBB, Def);
+  MoveDebugValues(Reg, Insert, MBB, MRI);
   LIS.handleMove(*Def);
 
   if (MRI.hasOneDef(Reg) && MRI.hasOneUse(Reg)) {
@@ -499,6 +522,8 @@ static MachineInstr *MoveForSingleUse(un
 
     MFI.stackifyVReg(NewReg);
 
+    UpdateDebugValuesReg(Reg, NewReg, MBB, MRI);
+
     LLVM_DEBUG(dbgs() << " - Replaced register: "; Def->dump());
   }
 
@@ -506,6 +531,29 @@ static MachineInstr *MoveForSingleUse(un
   return Def;
 }
 
+static void CloneDebugValues(unsigned Reg, MachineInstr *Insert,
+                             unsigned TargetReg, MachineBasicBlock &MBB,
+                             MachineRegisterInfo &MRI,
+                             const WebAssemblyInstrInfo *TII) {
+  SmallPtrSet<MachineInstr *, 4> Instrs;
+  for (auto &Op : MRI.reg_operands(Reg)) {
+    MachineInstr *MI = Op.getParent();
+    assert(MI != nullptr);
+    if (MI->isDebugValue() && MI->getParent() == &MBB &&
+        Instrs.find(MI) == Instrs.end())
+      Instrs.insert(MI);
+  }
+  for (const auto &MI : Instrs) {
+    MachineInstr &Clone = TII->duplicate(MBB, Insert, *MI);
+    for (unsigned i = 0, e = Clone.getNumOperands(); i != e; ++i) {
+      MachineOperand &MO = Clone.getOperand(i);
+      if (MO.isReg() && MO.getReg() == Reg)
+        MO.setReg(TargetReg);
+    }
+    LLVM_DEBUG(dbgs() << " - - Cloned DBG_VALUE: "; Clone.dump());
+  }
+}
+
 /// A trivially cloneable instruction; clone it and nest the new copy with the
 /// current instruction.
 static MachineInstr *RematerializeCheapDef(
@@ -536,6 +584,7 @@ static MachineInstr *RematerializeCheapD
   }
 
   // If that was the last use of the original, delete the original.
+  // Move or clone corresponding DBG_VALUEs to the 'Insert' location.
   if (IsDead) {
     LLVM_DEBUG(dbgs() << " - Deleting original\n");
     SlotIndex Idx = LIS.getInstructionIndex(Def).getRegSlot();
@@ -543,6 +592,11 @@ static MachineInstr *RematerializeCheapD
     LIS.removeInterval(Reg);
     LIS.RemoveMachineInstrFromMaps(Def);
     Def.eraseFromParent();
+
+    MoveDebugValues(Reg, &*Insert, MBB, MRI);
+    UpdateDebugValuesReg(Reg, NewReg, MBB, MRI);
+  } else {
+    CloneDebugValues(Reg, &*Insert, NewReg, MBB, MRI, TII);
   }
 
   return Clone;
@@ -592,6 +646,8 @@ static MachineInstr *MoveAndTeeForMultiU
   SlotIndex TeeIdx = LIS.InsertMachineInstrInMaps(*Tee).getRegSlot();
   SlotIndex DefIdx = LIS.getInstructionIndex(*Def).getRegSlot();
 
+  MoveDebugValues(Reg, Insert, MBB, MRI);
+
   // Tell LiveIntervals we moved the original vreg def from Def to Tee.
   LiveInterval &LI = LIS.getInterval(Reg);
   LiveInterval::iterator I = LI.FindSegmentContaining(DefIdx);
@@ -608,6 +664,9 @@ static MachineInstr *MoveAndTeeForMultiU
   ImposeStackOrdering(Def);
   ImposeStackOrdering(Tee);
 
+  CloneDebugValues(Reg, Tee, DefReg, MBB, MRI, TII);
+  CloneDebugValues(Reg, Insert, TeeReg, MBB, MRI, TII);
+
   LLVM_DEBUG(dbgs() << " - Replaced register: "; Def->dump());
   LLVM_DEBUG(dbgs() << " - Tee instruction: "; Tee->dump());
   return Def;

Added: llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move-2.ll?rev=343007&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move-2.ll (added)
+++ llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move-2.ll Tue Sep 25 11:59:34 2018
@@ -0,0 +1,82 @@
+; RUN: llc < %s -print-machineinstrs 2>&1 | FileCheck %s
+
+; CHECK: After WebAssembly Register Stackify:
+; CHECK: bb.2.for.body:
+; CHECK: [[REG:%[0-9]+]]:i32 = TEE_I32 {{.*}} fib2.c:6:7
+; CHECK-NEXT: DBG_VALUE debug-use [[REG]]:i32, debug-use $noreg, !"a", {{.*}} fib2.c:2:13
+; CHECK: After WebAssembly Register Coloring:
+
+; ModuleID = 'fib2.bc'
+; The test generated via: clang --target=wasm32-unknown-unknown-wasm fib2.c -g -O2
+; All non-"!dbg !18" llvm.dbg.value calls and attributes were removed.
+source_filename = "fib2.c"
+; int fib(int n) {
+;   int i, t, a = 0, b = 1;
+;   for (i = 0; i < n; i++) {
+;     t = a;
+;     a = b;
+;     b += t;
+;   }
+;   return b;
+; }
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown-wasm"
+
+; Function Attrs: nounwind readnone
+define hidden i32 @fib(i32 %n) local_unnamed_addr #0 !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 0, metadata !15, metadata !DIExpression()), !dbg !18
+  %cmp8 = icmp sgt i32 %n, 0, !dbg !21
+  br i1 %cmp8, label %for.body, label %for.end, !dbg !24
+
+for.body:                                         ; preds = %entry, %for.body
+  %b.011 = phi i32 [ %add, %for.body ], [ 1, %entry ]
+  %a.010 = phi i32 [ %b.011, %for.body ], [ 0, %entry ]
+  %i.09 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
+  call void @llvm.dbg.value(metadata i32 %a.010, metadata !15, metadata !DIExpression()), !dbg !18
+  %add = add nsw i32 %b.011, %a.010, !dbg !26
+  %inc = add nuw nsw i32 %i.09, 1, !dbg !28
+  call void @llvm.dbg.value(metadata i32 %b.011, metadata !15, metadata !DIExpression()), !dbg !18
+  %exitcond = icmp eq i32 %inc, %n, !dbg !21
+  br i1 %exitcond, label %for.end, label %for.body, !dbg !24, !llvm.loop !29
+
+for.end:                                          ; preds = %for.body, %entry
+  %b.0.lcssa = phi i32 [ 1, %entry ], [ %add, %for.body ]
+  ret i32 %b.0.lcssa, !dbg !31
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 7.0.0 (trunk 337180)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "fib2.c", directory: "/d/y/llvmwasm")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 7.0.0 (trunk 337180)"}
+!7 = distinct !DISubprogram(name: "fib", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!15}
+!15 = !DILocalVariable(name: "a", scope: !7, file: !1, line: 2, type: !10)
+!17 = !DILocation(line: 1, column: 13, scope: !7)
+!18 = !DILocation(line: 2, column: 13, scope: !7)
+!19 = !DILocation(line: 2, column: 20, scope: !7)
+!20 = !DILocation(line: 2, column: 7, scope: !7)
+!21 = !DILocation(line: 3, column: 17, scope: !22)
+!22 = distinct !DILexicalBlock(scope: !23, file: !1, line: 3, column: 3)
+!23 = distinct !DILexicalBlock(scope: !7, file: !1, line: 3, column: 3)
+!24 = !DILocation(line: 3, column: 3, scope: !23)
+!25 = !DILocation(line: 2, column: 10, scope: !7)
+!26 = !DILocation(line: 6, column: 7, scope: !27)
+!27 = distinct !DILexicalBlock(scope: !22, file: !1, line: 3, column: 27)
+!28 = !DILocation(line: 3, column: 23, scope: !22)
+!29 = distinct !{!29, !24, !30}
+!30 = !DILocation(line: 7, column: 3, scope: !23)
+!31 = !DILocation(line: 8, column: 3, scope: !7)

Added: llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move.ll?rev=343007&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move.ll (added)
+++ llvm/trunk/test/DebugInfo/WebAssembly/dbg-value-move.ll Tue Sep 25 11:59:34 2018
@@ -0,0 +1,133 @@
+; RUN: llc < %s -print-machineinstrs 2>&1 | FileCheck %s
+
+; CHECK: After WebAssembly Register Stackify:
+; CHECK: bb.3.for.body.for.body_crit_edge:
+; CHECK: [[REG:%[0-9]+]]:i32 = nsw ADD_I32 {{.*}} fib.c:7:7
+; CHECK-NEXT: DBG_VALUE debug-use [[REG]]:i32, debug-use $noreg, !"a", {{.*}} fib.c:5:13
+; CHECK: After WebAssembly Register Coloring:
+
+; ModuleID = 'fib.bc'
+; The test generated via: clang --target=wasm32-unknown-unknown-wasm fib.c -g -O2
+; All lifetime markers and attributes were removed.
+source_filename = "fib.c"
+; void swap(int* a, int* b);
+; 
+; __attribute__ ((visibility ("default")))
+; int fib(int n) {
+;   int i, t, a = 0, b = 1;
+;   for (i = 0; i < n; i++) {
+;     a += b;
+;     swap(&a, &b);
+;   }
+;   return b;
+; }
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown-wasm"
+
+; Function Attrs: nounwind
+define i32 @fib(i32 %n) local_unnamed_addr #0 !dbg !7 {
+entry:
+  %a = alloca i32, align 4
+  %b = alloca i32, align 4
+  call void @llvm.dbg.value(metadata i32 %n, metadata !12, metadata !DIExpression()), !dbg !17
+  %0 = bitcast i32* %a to i8*, !dbg !18
+  call void @llvm.dbg.value(metadata i32 0, metadata !15, metadata !DIExpression()), !dbg !19
+  store i32 0, i32* %a, align 4, !dbg !19, !tbaa !20
+  %1 = bitcast i32* %b to i8*, !dbg !18
+  call void @llvm.dbg.value(metadata i32 1, metadata !16, metadata !DIExpression()), !dbg !24
+  store i32 1, i32* %b, align 4, !dbg !24, !tbaa !20
+  call void @llvm.dbg.value(metadata i32 0, metadata !13, metadata !DIExpression()), !dbg !25
+  %cmp4 = icmp sgt i32 %n, 0, !dbg !26
+  call void @llvm.dbg.value(metadata i32 1, metadata !16, metadata !DIExpression()), !dbg !24
+  br i1 %cmp4, label %for.body.preheader, label %for.end, !dbg !29
+
+for.body.preheader:                               ; preds = %entry
+  call void @llvm.dbg.value(metadata i32 0, metadata !13, metadata !DIExpression()), !dbg !25
+  call void @llvm.dbg.value(metadata i32 0, metadata !15, metadata !DIExpression()), !dbg !19
+  call void @llvm.dbg.value(metadata i32 1, metadata !15, metadata !DIExpression()), !dbg !19
+  store i32 1, i32* %a, align 4, !dbg !30, !tbaa !20
+  call void @llvm.dbg.value(metadata i32* %a, metadata !15, metadata !DIExpression()), !dbg !19
+  call void @llvm.dbg.value(metadata i32* %b, metadata !16, metadata !DIExpression()), !dbg !24
+  call void @swap(i32* nonnull %a, i32* nonnull %b) #5, !dbg !32
+  call void @llvm.dbg.value(metadata i32 1, metadata !13, metadata !DIExpression()), !dbg !25
+  %2 = load i32, i32* %b, align 4, !dbg !33, !tbaa !20
+  call void @llvm.dbg.value(metadata i32 %2, metadata !16, metadata !DIExpression()), !dbg !24
+  %exitcond9 = icmp eq i32 %n, 1, !dbg !26
+  br i1 %exitcond9, label %for.end, label %for.body.for.body_crit_edge, !dbg !29, !llvm.loop !34
+
+for.body.for.body_crit_edge:                      ; preds = %for.body.preheader, %for.body.for.body_crit_edge
+  %3 = phi i32 [ %4, %for.body.for.body_crit_edge ], [ %2, %for.body.preheader ]
+  %inc10 = phi i32 [ %inc, %for.body.for.body_crit_edge ], [ 1, %for.body.preheader ]
+  %.pre = load i32, i32* %a, align 4, !dbg !30, !tbaa !20
+  call void @llvm.dbg.value(metadata i32 %inc10, metadata !13, metadata !DIExpression()), !dbg !25
+  call void @llvm.dbg.value(metadata i32 %.pre, metadata !15, metadata !DIExpression()), !dbg !19
+  %add = add nsw i32 %.pre, %3, !dbg !30
+  call void @llvm.dbg.value(metadata i32 %add, metadata !15, metadata !DIExpression()), !dbg !19
+  store i32 %add, i32* %a, align 4, !dbg !30, !tbaa !20
+  call void @llvm.dbg.value(metadata i32* %a, metadata !15, metadata !DIExpression()), !dbg !19
+  call void @llvm.dbg.value(metadata i32* %b, metadata !16, metadata !DIExpression()), !dbg !24
+  call void @swap(i32* nonnull %a, i32* nonnull %b) #5, !dbg !32
+  %inc = add nuw nsw i32 %inc10, 1, !dbg !36
+  call void @llvm.dbg.value(metadata i32 %inc, metadata !13, metadata !DIExpression()), !dbg !25
+  %4 = load i32, i32* %b, align 4, !dbg !33, !tbaa !20
+  call void @llvm.dbg.value(metadata i32 %4, metadata !16, metadata !DIExpression()), !dbg !24
+  %exitcond = icmp eq i32 %inc, %n, !dbg !26
+  br i1 %exitcond, label %for.end, label %for.body.for.body_crit_edge, !dbg !29, !llvm.loop !34
+
+for.end:                                          ; preds = %for.body.for.body_crit_edge, %for.body.preheader, %entry
+  %.lcssa = phi i32 [ 1, %entry ], [ %2, %for.body.preheader ], [ %4, %for.body.for.body_crit_edge ]
+  ret i32 %.lcssa, !dbg !38
+}
+
+declare void @swap(i32*, i32*) local_unnamed_addr #2
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #4
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 7.0.0 (trunk 334610)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "fib.c", directory: "/d/y/llvmwasm")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 7.0.0 (trunk 334610)"}
+!7 = distinct !DISubprogram(name: "fib", scope: !1, file: !1, line: 4, type: !8, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!12, !13, !14, !15, !16}
+!12 = !DILocalVariable(name: "n", arg: 1, scope: !7, file: !1, line: 4, type: !10)
+!13 = !DILocalVariable(name: "i", scope: !7, file: !1, line: 5, type: !10)
+!14 = !DILocalVariable(name: "t", scope: !7, file: !1, line: 5, type: !10)
+!15 = !DILocalVariable(name: "a", scope: !7, file: !1, line: 5, type: !10)
+!16 = !DILocalVariable(name: "b", scope: !7, file: !1, line: 5, type: !10)
+!17 = !DILocation(line: 4, column: 13, scope: !7)
+!18 = !DILocation(line: 5, column: 3, scope: !7)
+!19 = !DILocation(line: 5, column: 13, scope: !7)
+!20 = !{!21, !21, i64 0}
+!21 = !{!"int", !22, i64 0}
+!22 = !{!"omnipotent char", !23, i64 0}
+!23 = !{!"Simple C/C++ TBAA"}
+!24 = !DILocation(line: 5, column: 20, scope: !7)
+!25 = !DILocation(line: 5, column: 7, scope: !7)
+!26 = !DILocation(line: 6, column: 17, scope: !27)
+!27 = distinct !DILexicalBlock(scope: !28, file: !1, line: 6, column: 3)
+!28 = distinct !DILexicalBlock(scope: !7, file: !1, line: 6, column: 3)
+!29 = !DILocation(line: 6, column: 3, scope: !28)
+!30 = !DILocation(line: 7, column: 7, scope: !31)
+!31 = distinct !DILexicalBlock(scope: !27, file: !1, line: 6, column: 27)
+!32 = !DILocation(line: 8, column: 5, scope: !31)
+!33 = !DILocation(line: 0, scope: !7)
+!34 = distinct !{!34, !29, !35}
+!35 = !DILocation(line: 9, column: 3, scope: !28)
+!36 = !DILocation(line: 6, column: 23, scope: !27)
+!37 = !DILocation(line: 11, column: 1, scope: !7)
+!38 = !DILocation(line: 10, column: 3, scope: !7)
+!39 = distinct !DISubprogram(name: "_start", scope: !1, file: !1, line: 13, type: !40, isLocal: false, isDefinition: true, scopeLine: 13, isOptimized: true, unit: !0, retainedNodes: !2)
+!40 = !DISubroutineType(types: !41)
+!41 = !{null}
+!42 = !DILocation(line: 13, column: 16, scope: !39)




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