[llvm] r352467 - [DebugInfo][DAG] Process FrameIndex dbg.values unconditionally
Jeremy Morse via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 29 01:40:05 PST 2019
Author: jmorse
Date: Tue Jan 29 01:40:05 2019
New Revision: 352467
URL: http://llvm.org/viewvc/llvm-project?rev=352467&view=rev
Log:
[DebugInfo][DAG] Process FrameIndex dbg.values unconditionally
A FrameIndex should be valid throughout a block regardless of what instructions
get selected in that block -- therefore we shouldn't harness dbg.values that
refer to FrameIndexes to an SDNode. There are numerous codegen reasons why
an SDNode never appears or doesn't become a location that a DBG_VALUE can
refer to. None of them actually affect the variable location.
Therefore, before any other tests to encode dbg_values in a SelectionDAG,
identify FrameIndex operands and encode them unattached to any SDNode.
Differential Revision: https://reviews.llvm.org/D57328
Added:
llvm/trunk/test/DebugInfo/X86/dbg-value-frame-index-2.ll
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/trunk/test/DebugInfo/NVPTX/dbg-value-const-byref.ll
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=352467&r1=352466&r2=352467&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Tue Jan 29 01:40:05 2019
@@ -5320,6 +5320,21 @@ SelectionDAGBuilder::visitIntrinsicCall(
return nullptr;
}
+ // If the Value is a frame index, we can create a FrameIndex debug value
+ // without relying on the DAG at all.
+ if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
+ auto SI = FuncInfo.StaticAllocaMap.find(AI);
+ if (SI != FuncInfo.StaticAllocaMap.end()) {
+ auto SDV =
+ DAG.getFrameIndexDbgValue(Variable, Expression, SI->second,
+ /*IsIndirect*/ false, dl, SDNodeOrder);
+ // Do not attach the SDNodeDbgValue to an SDNode: this variable location
+ // is still available even if the SDNode gets optimized out.
+ DAG.AddDbgValue(SDV, nullptr, false);
+ return nullptr;
+ }
+ }
+
// Do not use getValue() in here; we don't want to generate code at
// this point if it hasn't been done yet.
SDValue N = NodeMap[V];
Modified: llvm/trunk/test/DebugInfo/NVPTX/dbg-value-const-byref.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/NVPTX/dbg-value-const-byref.ll?rev=352467&r1=352466&r2=352467&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/NVPTX/dbg-value-const-byref.ll (original)
+++ llvm/trunk/test/DebugInfo/NVPTX/dbg-value-const-byref.ll Tue Jan 29 01:40:05 2019
@@ -17,10 +17,10 @@
; particularly variables that are described as constants and passed
; by reference.
;
-; CHECK: DEBUG_VALUE: foo:i <- [DW_OP_deref] $vrdepot
; CHECK: DEBUG_VALUE: foo:i <- 3
; CHECK: DEBUG_VALUE: foo:i <- 7
; CHECK: DEBUG_VALUE: foo:i <- %
+; CHECK: DEBUG_VALUE: foo:i <- [DW_OP_deref] $vrdepot
; Function Attrs: nounwind ssp uwtable
define i32 @foo() #0 !dbg !4 {
Added: llvm/trunk/test/DebugInfo/X86/dbg-value-frame-index-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/dbg-value-frame-index-2.ll?rev=352467&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/dbg-value-frame-index-2.ll (added)
+++ llvm/trunk/test/DebugInfo/X86/dbg-value-frame-index-2.ll Tue Jan 29 01:40:05 2019
@@ -0,0 +1,79 @@
+; RUN: llc -start-after=codegenprepare -stop-before=expand-isel-pseudos < %s -o - | FileCheck %s
+
+; Test that stack frame dbg.values are lowered to DBG_VALUEs, in blocks that
+; are local to the alloca, and elsewhere. Differs from dbg-value-frame-index.ll
+; because this test does not result in the frame-index being in a vreg,
+; instead it's exclusively referred to by memory operands of instructions.
+;
+; Additionally test that we don't re-order with constant values -- both are
+; independent of the order the instructions get lowered, but should not
+; interleave.
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-unknown"
+
+declare void @dud()
+
+; CHECK: [[BARVAR:![0-9]+]] = !DILocalVariable(name: "bar",
+
+define i32 @foo() !dbg !6 {
+; CHECK-LABEL: body
+
+; CHECK: DBG_VALUE 0, $noreg, [[BARVAR]]
+; CHECK-NEXT: MOV32mi %[[STACKLOC:[a-zA-Z0-9\.]+]], 1, $noreg
+; CHECK-NEXT: DBG_VALUE %[[STACKLOC]], $noreg, [[BARVAR]]
+
+ %p1 = alloca i32
+ call void @llvm.dbg.value(metadata i32 *null, metadata !17, metadata !DIExpression()), !dbg !18
+ store i32 0, i32 *%p1
+ call void @llvm.dbg.value(metadata i32 *%p1, metadata !17, metadata !DIExpression()), !dbg !18
+ br label %foo
+
+foo:
+
+; CHECK-LABEL: bb.1.foo
+; CHECK: DBG_VALUE %[[STACKLOC]], $noreg, [[BARVAR]]
+
+ call void @dud()
+ call void @llvm.dbg.value(metadata i32 *%p1, metadata !17, metadata !DIExpression()), !dbg !18
+ br label %bar
+
+bar:
+
+; CHECK-LABEL: bb.2.bar
+; CHECK: DBG_VALUE %[[STACKLOC]], $noreg, [[BARVAR]]
+; CHECK-NEXT: ADJCALLSTACKDOWN
+; CHECK-NEXT: CALL
+; CHECK-NEXT: ADJCALLSTACKUP
+; CHECK-NEXT: DBG_VALUE 0, $noreg, [[BARVAR]]
+ call void @llvm.dbg.value(metadata i32 *%p1, metadata !17, metadata !DIExpression()), !dbg !18
+ call void @dud()
+ call void @llvm.dbg.value(metadata i32 *null, metadata !17, metadata !DIExpression()), !dbg !18
+ %loaded = load i32, i32 *%p1
+ ret i32 %loaded, !dbg !19
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #6
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+!llvm.ident = !{!5}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2)
+!1 = !DIFile(filename: "a.c", directory: "b")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!""}
+!6 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 13, type: !7, isLocal: false, isDefinition: true, scopeLine: 14, isOptimized: false, unit: !0, retainedNodes: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!140}
+!140 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !{!16}
+!16 = !DISubrange(count: 5)
+!17 = !DILocalVariable(name: "bar", scope: !6, line: 13, type: !140)
+!18 = !DILocation(line: 13, column: 23, scope: !6)
+!19 = !DILocation(line: 15, column: 5, scope: !6)
+!20 = !DILocation(line: 16, column: 1, scope: !6)
+!21 = !DILocalVariable(name: "baz", scope: !6, line: 13, type: !140)
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