[llvm] r278703 - Local variables whose address is taken and passed on to a call are described
Wolfgang Pieb via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 15 11:18:26 PDT 2016
Author: wolfgangp
Date: Mon Aug 15 13:18:26 2016
New Revision: 278703
URL: http://llvm.org/viewvc/llvm-project?rev=278703&view=rev
Log:
Local variables whose address is taken and passed on to a call are described
in debug info using their stack slots instead of as an indirection of param reg + 0
offset. This is done by detecting FrameIndexSDNodes in SelectionDAG and generating
FrameIndexDbgValues for them. This ultimately generates DBG_VALUEs with stack
location operands.
Differential Revision: http://reviews.llvm.org/D23283
Added:
llvm/trunk/test/DebugInfo/X86/debug-loc-frame.ll
Modified:
llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
llvm/trunk/test/DebugInfo/AArch64/coalescing.ll
llvm/trunk/test/DebugInfo/X86/array.ll
llvm/trunk/test/DebugInfo/X86/bbjoin.ll
llvm/trunk/test/DebugInfo/X86/dbg-value-const-byref.ll
Modified: llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DebugInfoMetadata.h?rev=278703&r1=278702&r2=278703&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/DebugInfoMetadata.h (original)
+++ llvm/trunk/include/llvm/IR/DebugInfoMetadata.h Mon Aug 15 13:18:26 2016
@@ -2155,6 +2155,11 @@ public:
static bool classof(const Metadata *MD) {
return MD->getMetadataID() == DIExpressionKind;
}
+
+ /// \brief Is the first element a DW_OP_deref?.
+ bool startsWithDeref() const {
+ return getNumElements() > 0 && getElement(0) == dwarf::DW_OP_deref;
+ }
};
class DIObjCProperty : public DINode {
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=278703&r1=278702&r2=278703&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Mon Aug 15 13:18:26 2016
@@ -1020,8 +1020,7 @@ void SelectionDAGBuilder::resolveDanglin
if (Val.getNode()) {
if (!EmitFuncArgumentDbgValue(V, Variable, Expr, dl, Offset, false,
Val)) {
- SDV = DAG.getDbgValue(Variable, Expr, Val.getNode(), Val.getResNo(),
- false, Offset, dl, DbgSDNodeOrder);
+ SDV = getDbgValue(Val, Variable, Expr, Offset, dl, DbgSDNodeOrder);
DAG.AddDbgValue(SDV, Val.getNode(), false);
}
} else
@@ -4742,6 +4741,32 @@ bool SelectionDAGBuilder::EmitFuncArgume
return true;
}
+/// Return the appropriate SDDbgValue based on N.
+SDDbgValue *SelectionDAGBuilder::getDbgValue(SDValue N,
+ DILocalVariable *Variable,
+ DIExpression *Expr, int64_t Offset,
+ DebugLoc dl,
+ unsigned DbgSDNodeOrder) {
+ SDDbgValue *SDV;
+ auto *FISDN = dyn_cast<FrameIndexSDNode>(N.getNode());
+ if (FISDN && Expr->startsWithDeref()) {
+ // Construct a FrameIndexDbgValue for FrameIndexSDNodes so we can describe
+ // stack slot locations as such instead of as indirectly addressed
+ // locations.
+ ArrayRef<uint64_t> TrailingElements(Expr->elements_begin() + 1,
+ Expr->elements_end());
+ DIExpression *DerefedDIExpr =
+ DIExpression::get(*DAG.getContext(), TrailingElements);
+ int FI = FISDN->getIndex();
+ SDV = DAG.getFrameIndexDbgValue(Variable, DerefedDIExpr, FI, 0, dl,
+ DbgSDNodeOrder);
+ } else {
+ SDV = DAG.getDbgValue(Variable, Expr, N.getNode(), N.getResNo(), false,
+ Offset, dl, DbgSDNodeOrder);
+ }
+ return SDV;
+}
+
// VisualStudio defines setjmp as _setjmp
#if defined(_MSC_VER) && defined(setjmp) && \
!defined(setjmp_undefined_for_msvc)
@@ -4943,8 +4968,7 @@ SelectionDAGBuilder::visitIntrinsicCall(
if (N.getNode()) {
if (!EmitFuncArgumentDbgValue(V, Variable, Expression, dl, Offset,
false, N)) {
- SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
- false, Offset, dl, SDNodeOrder);
+ SDV = getDbgValue(N, Variable, Expression, Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, N.getNode(), false);
}
} else if (!V->use_empty() ) {
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h?rev=278703&r1=278702&r2=278703&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h Mon Aug 15 13:18:26 2016
@@ -942,6 +942,11 @@ private:
/// Update the DAG and DAG builder with the relevant information after
/// a new root node has been created which could be a tail call.
void updateDAGForMaybeTailCall(SDValue MaybeTC);
+
+ /// Return the appropriate SDDbgValue based on N.
+ SDDbgValue *getDbgValue(SDValue N, DILocalVariable *Variable,
+ DIExpression *Expr, int64_t Offset, DebugLoc dl,
+ unsigned DbgSDNodeOrder);
};
/// RegsForValue - This struct represents the registers (physical or virtual)
Modified: llvm/trunk/test/DebugInfo/AArch64/coalescing.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/AArch64/coalescing.ll?rev=278703&r1=278702&r2=278703&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/AArch64/coalescing.ll (original)
+++ llvm/trunk/test/DebugInfo/AArch64/coalescing.ll Mon Aug 15 13:18:26 2016
@@ -25,7 +25,8 @@ entry:
; CHECK-NEXT: DW_AT_location
; CHECK-NEXT: DW_AT_name {{.*}}"size"
; CHECK: .debug_loc contents:
- ; CHECK: Location description: 70 00
+ ; Expecting the encoding for sp+12: DW_OP_breg31 0c
+ ; CHECK: Location description: 8f 0c
ret void, !dbg !18
}
Modified: llvm/trunk/test/DebugInfo/X86/array.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/array.ll?rev=278703&r1=278702&r2=278703&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/array.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/array.ll Mon Aug 15 13:18:26 2016
@@ -16,9 +16,7 @@
; Test that we only emit register-indirect locations for the array array.
; rdar://problem/14874886
;
-; FIXME: If we described this location as RSP-relative instead of RDI-relative
-; the live range would be larger.
-; CHECK: ##DEBUG_VALUE: main:array <- [%RDI+0]
+; CHECK: ##DEBUG_VALUE: main:array <- [%RSP+0]
; CHECK-NOT: ##DEBUG_VALUE: main:array <- %R{{.*}}
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.9.0"
Modified: llvm/trunk/test/DebugInfo/X86/bbjoin.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/bbjoin.ll?rev=278703&r1=278702&r2=278703&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/bbjoin.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/bbjoin.ll Mon Aug 15 13:18:26 2016
@@ -12,7 +12,7 @@
; CHECK: ![[X:.*]] = !DILocalVariable(name: "x",
; CHECK: bb.0.entry:
; CHECK: DBG_VALUE 23, 0, ![[X]],
-; CHECK: DBG_VALUE debug-use %rdi, debug-use _, ![[X]]
+; CHECK: DBG_VALUE %rsp, 4, ![[X]]
; CHECK: bb.1.if.then:
; CHECK: DBG_VALUE 43, 0, ![[X]],
; CHECK: bb.2.if.end:
Modified: llvm/trunk/test/DebugInfo/X86/dbg-value-const-byref.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/dbg-value-const-byref.ll?rev=278703&r1=278702&r2=278703&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/dbg-value-const-byref.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/dbg-value-const-byref.ll Mon Aug 15 13:18:26 2016
@@ -41,7 +41,8 @@
; rdi+0
; CHECK: Beginning address offset: [[R1]]
; CHECK: Ending address offset: [[R2:.*]]
-; CHECK: Location description: 75 00
+; CHECK: Location description: 77 04
+; rsp+4
;
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.9.0"
Added: llvm/trunk/test/DebugInfo/X86/debug-loc-frame.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/debug-loc-frame.ll?rev=278703&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/debug-loc-frame.ll (added)
+++ llvm/trunk/test/DebugInfo/X86/debug-loc-frame.ll Mon Aug 15 13:18:26 2016
@@ -0,0 +1,113 @@
+; REQUIRES: object-emission
+
+; Check that when variables are allocated on the stack we generate debug locations
+; for the stack location directly instead of generating a register+offset indirection.
+
+; RUN: %llc_dwarf -O2 -filetype=obj -disable-post-ra < %s | llvm-dwarfdump - | FileCheck %s
+;
+; int data = 17;
+; int sum = 0;
+; int zero = 0;
+; int *ptr;
+;
+; extern void foo(int i, int *p);
+;
+; int main()
+; {
+; int val;
+; val = data;
+; foo(1, &val);
+; foo(2, &data);
+; return zero;
+; }
+;
+; CHECK: .debug_info contents
+; CHECK: DW_TAG_subprogram
+; CHECK-NOT: NULL
+; CHECK: DW_TAG_variable
+; CHECK: DW_AT_location [DW_FORM_sec_offset] ([[DEBUGLOCOFFSET:0x[0-9a-f]+]]){{[[:space:]].*}}"val"
+
+; See that 'val' has at least one location entry with a DW_op_breg? operand.
+; The DWARF DW_op_breg* ops are encoded from 0x70 to 0x8f, but checking for an
+; op in the range from 0x70 to 0x7f should suffice because that range covers
+; all integer GPRs.
+;
+; CHECK: .debug_loc contents:
+; CHECK-NOT: .debug{{.*}} contents
+; CHECK: [[DEBUGLOCOFFSET]]: Beginning
+; CHECK-NOT: {{0x[0-9a-f]+}}: Beginning
+; CHECK: Location description: 7{{[0-9a-f] .*}}
+
+; ModuleID = 'frame.c'
+source_filename = "frame.c"
+
+ at data = global i32 17, align 4
+ at sum = local_unnamed_addr global i32 0, align 4
+ at zero = local_unnamed_addr global i32 0, align 4
+ at ptr = common local_unnamed_addr global i32* null, align 8
+
+; Function Attrs: nounwind uwtable
+define i32 @main() local_unnamed_addr !dbg !13 {
+entry:
+ %val = alloca i32, align 4
+ %0 = bitcast i32* %val to i8*, !dbg !18
+ call void @llvm.lifetime.start(i64 4, i8* %0), !dbg !18
+ %1 = load i32, i32* @data, align 4, !dbg !19, !tbaa !20
+ tail call void @llvm.dbg.value(metadata i32 %1, i64 0, metadata !17, metadata !24), !dbg !25
+ store i32 %1, i32* %val, align 4, !dbg !26, !tbaa !20
+ tail call void @llvm.dbg.value(metadata i32* %val, i64 0, metadata !17, metadata !27), !dbg !25
+ call void @foo(i32 1, i32* nonnull %val), !dbg !28
+ call void @foo(i32 2, i32* nonnull @data), !dbg !29
+ %2 = load i32, i32* @zero, align 4, !dbg !30, !tbaa !20
+ call void @llvm.lifetime.end(i64 4, i8* %0), !dbg !31
+ ret i32 %2, !dbg !32
+}
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start(i64, i8* nocapture)
+
+declare void @foo(i32, i32*) local_unnamed_addr
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end(i64, i8* nocapture)
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!10, !11}
+!llvm.ident = !{!12}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.9.0 (trunk 273961)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3)
+!1 = !DIFile(filename: "frame.c", directory: "/home/user/test")
+!2 = !{}
+!3 = !{!4, !6, !7, !8}
+!4 = distinct !DIGlobalVariable(name: "data", scope: !0, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, variable: i32* @data)
+!5 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!6 = distinct !DIGlobalVariable(name: "sum", scope: !0, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, variable: i32* @sum)
+!7 = distinct !DIGlobalVariable(name: "zero", scope: !0, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, variable: i32* @zero)
+!8 = distinct !DIGlobalVariable(name: "ptr", scope: !0, file: !1, line: 4, type: !9, isLocal: false, isDefinition: true, variable: i32** @ptr)
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !5, size: 64, align: 64)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{!"clang version 3.9.0 (trunk 273961)"}
+!13 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 8, type: !14, isLocal: false, isDefinition: true, scopeLine: 9, isOptimized: true, unit: !0, variables: !16)
+!14 = !DISubroutineType(types: !15)
+!15 = !{!5}
+!16 = !{!17}
+!17 = !DILocalVariable(name: "val", scope: !13, file: !1, line: 10, type: !5)
+!18 = !DILocation(line: 10, column: 3, scope: !13)
+!19 = !DILocation(line: 11, column: 9, scope: !13)
+!20 = !{!21, !21, i64 0}
+!21 = !{!"int", !22, i64 0}
+!22 = !{!"omnipotent char", !23, i64 0}
+!23 = !{!"Simple C/C++ TBAA"}
+!24 = !DIExpression()
+!25 = !DILocation(line: 10, column: 7, scope: !13)
+!26 = !DILocation(line: 11, column: 7, scope: !13)
+!27 = !DIExpression(DW_OP_deref)
+!28 = !DILocation(line: 12, column: 3, scope: !13)
+!29 = !DILocation(line: 13, column: 3, scope: !13)
+!30 = !DILocation(line: 14, column: 10, scope: !13)
+!31 = !DILocation(line: 15, column: 1, scope: !13)
+!32 = !DILocation(line: 14, column: 3, scope: !13)
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