[llvm] 620a529 - [Assignment Tracking] Choose better passes for RemoveRedundantDbgInstrs call
via llvm-commits
llvm-commits at lists.llvm.org
Wed Feb 22 08:29:43 PST 2023
Author: OCHyams
Date: 2023-02-22T16:28:06Z
New Revision: 620a529760e24820d94335be807cc22b6f389a5d
URL: https://github.com/llvm/llvm-project/commit/620a529760e24820d94335be807cc22b6f389a5d
DIFF: https://github.com/llvm/llvm-project/commit/620a529760e24820d94335be807cc22b6f389a5d.diff
LOG: [Assignment Tracking] Choose better passes for RemoveRedundantDbgInstrs call
Enabling assignment tracking without this patch, a significant amount of
additional compiler run time comes from the RemoveRedundantDbgInstrs call in
InstCombine. This patch reduces compiler run time by choosing better places to
call RemoveRedundantDbgInstrs.
In non-assignment-tracking builds, RemoveRedundantDbgInstrs is called by
InstCombine if LowerDbgDeclare makes a change (i.e. it is _sometimes_
called). In assignment tracking builds LowerDbgDeclare doesn't do anything. We
still need to clean up redundant intrinsics to avoid a large performance hit
due to the number of instructions, so the current approach is to have
InstCombine _always_ call RemoveRedundantDbgInstrs.
Instrumenting the compiler to run RemoveRedundantDbgInstrs after every pass and
dump the numbers and building CTMark/tramp3d-v4 indicates that SROA and
LoopVectorize give us a bigger bang (number removed) for buck (times pass is
run).
The compile time tracker reports that this patch reduces the number of
instructions retired building CTMark projects by an average of 1.1%.
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D144483
Added:
llvm/test/DebugInfo/Generic/assignment-tracking/loop-vectorize/remove-redundant-dbg.ll
llvm/test/DebugInfo/Generic/assignment-tracking/sroa/remove-redundant-dbg.ll
Modified:
llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
llvm/lib/Transforms/Scalar/SROA.cpp
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/test/DebugInfo/Generic/assignment-tracking/instcombine/remove-redundant-dbg.ll
llvm/test/DebugInfo/Generic/assignment-tracking/sroa/after-inlining.ll
llvm/test/DebugInfo/Generic/assignment-tracking/sroa/user-memcpy.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 2621a839784e9..34d1b2b46db29 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -4594,13 +4594,6 @@ static bool combineInstructionsOverFunction(
bool MadeIRChange = false;
if (ShouldLowerDbgDeclare)
MadeIRChange = LowerDbgDeclare(F);
- // LowerDbgDeclare calls RemoveRedundantDbgInstrs, but LowerDbgDeclare will
- // almost never return true when running an assignment tracking build. Take
- // this opportunity to do some clean up for assignment tracking builds too.
- if (!MadeIRChange && isAssignmentTrackingEnabled(*F.getParent())) {
- for (auto &BB : F)
- RemoveRedundantDbgInstrs(&BB);
- }
// Iterate while there is work to do.
unsigned Iteration = 0;
diff --git a/llvm/lib/Transforms/Scalar/SROA.cpp b/llvm/lib/Transforms/Scalar/SROA.cpp
index 0dc89919cf3b8..a3185e0101ba4 100644
--- a/llvm/lib/Transforms/Scalar/SROA.cpp
+++ b/llvm/lib/Transforms/Scalar/SROA.cpp
@@ -5048,6 +5048,11 @@ PreservedAnalyses SROAPass::runImpl(Function &F, DomTreeUpdater &RunDTU,
if (!Changed)
return PreservedAnalyses::all();
+ if (isAssignmentTrackingEnabled(*F.getParent())) {
+ for (auto &BB : F)
+ RemoveRedundantDbgInstrs(&BB);
+ }
+
PreservedAnalyses PA;
if (!CFGChanged)
PA.preserveSet<CFGAnalyses>();
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 8db1e1429bb4f..cd5ddf2862352 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -98,6 +98,7 @@
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/DerivedTypes.h"
@@ -10606,6 +10607,11 @@ PreservedAnalyses LoopVectorizePass::run(Function &F,
return PreservedAnalyses::all();
PreservedAnalyses PA;
+ if (isAssignmentTrackingEnabled(*F.getParent())) {
+ for (auto &BB : F)
+ RemoveRedundantDbgInstrs(&BB);
+ }
+
// We currently do not preserve loopinfo/dominator analyses with outer loop
// vectorization. Until this is addressed, mark these analyses as preserved
// only for non-VPlan-native path.
diff --git a/llvm/test/DebugInfo/Generic/assignment-tracking/instcombine/remove-redundant-dbg.ll b/llvm/test/DebugInfo/Generic/assignment-tracking/instcombine/remove-redundant-dbg.ll
index 44e9281336b70..11895098179eb 100644
--- a/llvm/test/DebugInfo/Generic/assignment-tracking/instcombine/remove-redundant-dbg.ll
+++ b/llvm/test/DebugInfo/Generic/assignment-tracking/instcombine/remove-redundant-dbg.ll
@@ -1,17 +1,17 @@
-; RUN: opt -passes=instcombine -S %s -o - \
+; RUN: opt -passes=sroa -S %s -o - \
; RUN: | FileCheck %s --implicit-check-not="call void @llvm.dbg"
-;; Check that instcombine removes redundant debug intrinsics. This has a
-;; significant positive impact on peak memory. CTMark's tramp3d-v4's peak
-;; memory with assignment tracking enabled is reduced by about 15% with this
-;; change.
+;; Check that sroa removes redundant debug intrinsics after it makes a
+;; change. This has a significant positive impact on peak memory and compiler
+;; run time.
; CHECK: @llvm.dbg.assign(metadata i32 1
define dso_local void @_Z3funv() local_unnamed_addr !dbg !7 {
entry:
- call void @llvm.dbg.assign(metadata i32 undef, metadata !11, metadata !DIExpression(), metadata !13, metadata ptr undef, metadata !DIExpression()), !dbg !14
- call void @_Z3extv(), !dbg !15
+ %sroa-remove-me = alloca i32
+ call void @llvm.dbg.assign(metadata i32 undef, metadata !11, metadata !DIExpression(), metadata !13, metadata ptr undef, metadata !DIExpression()), !dbg !14
+ call void @_Z3extv(), !dbg !15
call void @llvm.dbg.assign(metadata i32 0, metadata !11, metadata !DIExpression(), metadata !13, metadata ptr undef, metadata !DIExpression()), !dbg !14
call void @llvm.dbg.assign(metadata i32 1, metadata !11, metadata !DIExpression(), metadata !13, metadata ptr undef, metadata !DIExpression()), !dbg !14
ret void, !dbg !16
diff --git a/llvm/test/DebugInfo/Generic/assignment-tracking/loop-vectorize/remove-redundant-dbg.ll b/llvm/test/DebugInfo/Generic/assignment-tracking/loop-vectorize/remove-redundant-dbg.ll
new file mode 100644
index 0000000000000..b02203dd99ba8
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/assignment-tracking/loop-vectorize/remove-redundant-dbg.ll
@@ -0,0 +1,61 @@
+; RUN: opt %s -passes=loop-vectorize -force-vector-width=2 -force-vector-interleave=2 -S -o - \
+; RUN: | FileCheck %s --implicit-check-not="call void @llvm.dbg"
+
+;; Check that loop-vectorize removes redundant debug intrinsics after it makes
+;; a change. This has a significant positive impact on peak memory and compiler
+;; run time.
+
+;; Check there is only one dbg.assign.
+; CHECK: call void @llvm.dbg.assign
+
+;; Check that the loop was actually modified.
+; CHECK: extractelement
+
+
+define void @test1(ptr noalias nocapture %a, ptr noalias nocapture readonly %b) {
+entry:
+ call void @llvm.dbg.assign(metadata ptr %a, metadata !11, metadata !DIExpression(), metadata !16, metadata ptr undef, metadata !DIExpression()), !dbg !28
+ call void @llvm.dbg.assign(metadata ptr %a, metadata !11, metadata !DIExpression(), metadata !16, metadata ptr undef, metadata !DIExpression()), !dbg !28
+ br label %for.body
+
+for.body: ; preds = %for.body, %entry
+ %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+ %arrayidx = getelementptr inbounds float, ptr %b, i64 %indvars.iv
+ %0 = load float, ptr %arrayidx, align 4
+ %cmp1 = fcmp ogt float %0, 1.000000e+02
+ tail call void @llvm.assume(i1 %cmp1)
+ %add = fadd float %0, 1.000000e+00
+ %arrayidx5 = getelementptr inbounds float, ptr %a, i64 %indvars.iv
+ store float %add, ptr %arrayidx5, align 4
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ %exitcond = icmp eq i64 %indvars.iv, 1599
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end: ; preds = %for.body
+ ret void
+}
+
+declare void @llvm.assume(i1) #0
+declare void @llvm.dbg.assign(metadata, metadata, metadata, metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !1000}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 14.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "/")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 4}
+!5 = !{i32 7, !"uwtable", i32 1}
+!6 = !{!"clang version 14.0.0)"}
+!7 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !{!11}
+!11 = !DILocalVariable(name: "Counter", scope: !7, file: !1, line: 3, type: !12)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!16 = distinct !DIAssignID()
+!19 = distinct !DILexicalBlock(scope: !7, file: !1, line: 4, column: 3)
+!28 = !DILocation(line: 6, column: 1, scope: !7)
+!1000 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
diff --git a/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/after-inlining.ll b/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/after-inlining.ll
index d4e98882bd785..16acdb4453126 100644
--- a/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/after-inlining.ll
+++ b/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/after-inlining.ll
@@ -28,7 +28,7 @@
;;
;; $ clang test.c -Xclang -fexperimental-assignment-tracking -O2 -g
-; CHECK: call void @llvm.dbg.assign(metadata i1 undef, metadata !{{.+}}, metadata !DIExpression(), metadata !{{.+}}, metadata ptr undef, metadata !DIExpression()), !dbg ![[DBG:[0-9]+]]
+; CHECK: call void @llvm.dbg.assign(metadata i1 false, metadata !{{.+}}, metadata !DIExpression(), metadata !{{.+}}, metadata ptr undef, metadata !DIExpression()), !dbg ![[DBG:[0-9]+]]
; CHECK-DAG: ![[DBG]] = !DILocation(line: 0, scope: ![[INL_SC:[0-9]+]], inlinedAt: ![[IA:[0-9]+]])
; CHECK-DAG: ![[IA]] = distinct !DILocation(line: 21, column: 12, scope: ![[SC:[0-9]+]])
@@ -47,7 +47,9 @@ declare void @llvm.lifetime.end.p0i8(i64 immarg, ptr nocapture) #2
define dso_local void @l() local_unnamed_addr #4 !dbg !73 {
entry:
%j.i = alloca %struct.c, align 4, !DIAssignID !74
- call void @llvm.dbg.assign(metadata i1 undef, metadata !64, metadata !DIExpression(), metadata !74, metadata ptr %j.i, metadata !DIExpression()) #5, !dbg !75
+ ; NOTE: this has been changed from undef to false so that the intrinsic isn't
+ ; deleted as redundant.
+ call void @llvm.dbg.assign(metadata i1 false, metadata !64, metadata !DIExpression(), metadata !74, metadata ptr %j.i, metadata !DIExpression()) #5, !dbg !75
%0 = bitcast ptr %j.i to ptr, !dbg !77
call void @llvm.lifetime.start.p0i8(i64 4, ptr nonnull %0) #5, !dbg !77
%arrayidx.i.i = getelementptr inbounds %struct.c, ptr %j.i, i64 0, i32 1, i64 0, !dbg !78
diff --git a/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/remove-redundant-dbg.ll b/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/remove-redundant-dbg.ll
new file mode 100644
index 0000000000000..11895098179eb
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/remove-redundant-dbg.ll
@@ -0,0 +1,46 @@
+; RUN: opt -passes=sroa -S %s -o - \
+; RUN: | FileCheck %s --implicit-check-not="call void @llvm.dbg"
+
+;; Check that sroa removes redundant debug intrinsics after it makes a
+;; change. This has a significant positive impact on peak memory and compiler
+;; run time.
+
+; CHECK: @llvm.dbg.assign(metadata i32 1
+
+define dso_local void @_Z3funv() local_unnamed_addr !dbg !7 {
+entry:
+ %sroa-remove-me = alloca i32
+ call void @llvm.dbg.assign(metadata i32 undef, metadata !11, metadata !DIExpression(), metadata !13, metadata ptr undef, metadata !DIExpression()), !dbg !14
+ call void @_Z3extv(), !dbg !15
+ call void @llvm.dbg.assign(metadata i32 0, metadata !11, metadata !DIExpression(), metadata !13, metadata ptr undef, metadata !DIExpression()), !dbg !14
+ call void @llvm.dbg.assign(metadata i32 1, metadata !11, metadata !DIExpression(), metadata !13, metadata ptr undef, metadata !DIExpression()), !dbg !14
+ ret void, !dbg !16
+}
+
+declare !dbg !17 dso_local void @_Z3extv() local_unnamed_addr
+declare void @llvm.dbg.assign(metadata, metadata, metadata, metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !1000}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 14.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "/")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 4}
+!5 = !{i32 7, !"uwtable", i32 1}
+!6 = !{!"clang version 14.0.0)"}
+!7 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !{!11}
+!11 = !DILocalVariable(name: "a", scope: !7, file: !1, line: 2, type: !12)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = distinct !DIAssignID()
+!14 = !DILocation(line: 0, scope: !7)
+!15 = !DILocation(line: 2, column: 25, scope: !7)
+!16 = !DILocation(line: 2, column: 32, scope: !7)
+!17 = !DISubprogram(name: "ext", linkageName: "_Z3extv", scope: !1, file: !1, line: 1, type: !8, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !18)
+!18 = !{}
+!1000 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
diff --git a/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/user-memcpy.ll b/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/user-memcpy.ll
index a652a295dec13..ad43744aa86b2 100644
--- a/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/user-memcpy.ll
+++ b/llvm/test/DebugInfo/Generic/assignment-tracking/sroa/user-memcpy.ll
@@ -25,7 +25,6 @@
;; | V3i point = {0, 0, 0};
; CHECK-NEXT: call void @llvm.dbg.assign(metadata i64 0, metadata ![[point:[0-9]+]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 64), metadata !{{.+}}, metadata ptr undef, metadata !DIExpression()), !dbg
; CHECK-NEXT: call void @llvm.dbg.assign(metadata i64 0, metadata ![[point]], metadata !DIExpression(DW_OP_LLVM_fragment, 64, 64), metadata !{{.+}}, metadata ptr undef, metadata !DIExpression()), !dbg
-; CHECK-NEXT: call void @llvm.dbg.assign(metadata i64 0, metadata ![[point]], metadata !DIExpression(DW_OP_LLVM_fragment, 128, 64), metadata !{{.+}}, metadata ptr undef, metadata !DIExpression()), !dbg
;; point.z = 5000;
; CHECK-NEXT: call void @llvm.dbg.assign(metadata i64 5000, metadata ![[point]], metadata !DIExpression(DW_OP_LLVM_fragment, 128, 64), metadata !{{.+}}, metadata ptr undef, metadata !DIExpression()), !dbg
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