llvm-6502/test/DebugInfo/AArch64/struct_by_value.ll

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; A by-value struct is a register-indirect value (breg).
; RUN: llc %s -filetype=asm -o - | FileCheck %s
Generate better location ranges for some register-described variables. Don't terminate location ranges for register-described variables at the end of machine basic block if this register is never modified in the function body, except for the prologue and epilogue. Prologue location is guessed by FrameSetup flags on MachineInstructions, while epilogue location is deduced from debug locations of instructions in the basic blocks ending with return instructions. This patch is mostly targeted to fix non-trivial debug locations for variables addressed via stack and frame pointers. It is not really a generic fix. We can still produce poor debug info for register-described variables if this register *is* modified somewhere in the function, but in unrelated places. This might be the case for the debug info in optimized binaries (e.g. for local variables in inlined functions). LiveDebugVariables pass in CodeGen attempts to fix this problem by adjusting DBG_VALUE instructions, but this pass is tied to greedy register allocator, which is used in optimized builds only. Proper fix would likely involve generalizing LiveDebugVariables to all register allocators. See more discussion in http://reviews.llvm.org/D3933 review thread. I'm proceeding with this patch to fix immediate severe problems and important cases, e.g. fix completely broken debug info with AddressSanitizer and fix PR19307 (missing debug info for by-value std::string arguments). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210492 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-09 21:53:47 +00:00
; CHECK: DW_AT_location
; CHECK-NEXT: .byte 112
; 112 = 0x70 = DW_OP_breg0
; rdar://problem/13658587
;
; Generated from
;
; struct five
; {
; int a;
; int b;
; int c;
; int d;
; int e;
; };
;
; int
; return_five_int (struct five f)
; {
; return f.a;
; }
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n32:64-S128"
target triple = "arm64-apple-ios3.0.0"
%struct.five = type { i32, i32, i32, i32, i32 }
; Function Attrs: nounwind ssp
define i32 @return_five_int(%struct.five* %f) #0 {
entry:
call void @llvm.dbg.declare(metadata !{%struct.five* %f}, metadata !17, metadata !{metadata !"0x102"}), !dbg !18
%a = getelementptr inbounds %struct.five* %f, i32 0, i32 0, !dbg !19
%0 = load i32* %a, align 4, !dbg !19
ret i32 %0, !dbg !19
}
; Function Attrs: nounwind readnone
Move the complex address expression out of DIVariable and into an extra argument of the llvm.dbg.declare/llvm.dbg.value intrinsics. Previously, DIVariable was a variable-length field that has an optional reference to a Metadata array consisting of a variable number of complex address expressions. In the case of OpPiece expressions this is wasting a lot of storage in IR, because when an aggregate type is, e.g., SROA'd into all of its n individual members, the IR will contain n copies of the DIVariable, all alike, only differing in the complex address reference at the end. By making the complex address into an extra argument of the dbg.value/dbg.declare intrinsics, all of the pieces can reference the same variable and the complex address expressions can be uniqued across the CU, too. Down the road, this will allow us to move other flags, such as "indirection" out of the DIVariable, too. The new intrinsics look like this: declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr) declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr) This patch adds a new LLVM-local tag to DIExpressions, so we can detect and pretty-print DIExpression metadata nodes. What this patch doesn't do: This patch does not touch the "Indirect" field in DIVariable; but moving that into the expression would be a natural next step. http://reviews.llvm.org/D4919 rdar://problem/17994491 Thanks to dblaikie and dexonsmith for reviewing this patch! Note: I accidentally committed a bogus older version of this patch previously. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218787 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 18:55:02 +00:00
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
attributes #0 = { nounwind ssp }
attributes #1 = { nounwind readnone }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!16, !20}
!0 = metadata !{metadata !"0x11\0012\00LLVM version 3.4 \000\00\000\00\000", metadata !1, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2} ; [ DW_TAG_compile_unit ] [struct_by_value.c] [DW_LANG_C99]
!1 = metadata !{metadata !"struct_by_value.c", metadata !""}
!2 = metadata !{}
!3 = metadata !{metadata !4}
!4 = metadata !{metadata !"0x2e\00return_five_int\00return_five_int\00\0013\000\001\000\006\00256\000\0014", metadata !1, metadata !5, metadata !6, null, i32 (%struct.five*)* @return_five_int, null, null, metadata !2} ; [ DW_TAG_subprogram ] [line 13] [def] [scope 14] [return_five_int]
!5 = metadata !{metadata !"0x29", metadata !1} ; [ DW_TAG_file_type ] [struct_by_value.c]
!6 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", i32 0, null, null, metadata !7, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!7 = metadata !{metadata !8, metadata !9}
!8 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
!9 = metadata !{metadata !"0x13\00five\001\00160\0032\000\000\000", metadata !1, null, null, metadata !10, null, null, null} ; [ DW_TAG_structure_type ] [five] [line 1, size 160, align 32, offset 0] [def] [from ]
!10 = metadata !{metadata !11, metadata !12, metadata !13, metadata !14, metadata !15}
!11 = metadata !{metadata !"0xd\00a\003\0032\0032\000\000", metadata !1, metadata !9, metadata !8} ; [ DW_TAG_member ] [a] [line 3, size 32, align 32, offset 0] [from int]
!12 = metadata !{metadata !"0xd\00b\004\0032\0032\0032\000", metadata !1, metadata !9, metadata !8} ; [ DW_TAG_member ] [b] [line 4, size 32, align 32, offset 32] [from int]
!13 = metadata !{metadata !"0xd\00c\005\0032\0032\0064\000", metadata !1, metadata !9, metadata !8} ; [ DW_TAG_member ] [c] [line 5, size 32, align 32, offset 64] [from int]
!14 = metadata !{metadata !"0xd\00d\006\0032\0032\0096\000", metadata !1, metadata !9, metadata !8} ; [ DW_TAG_member ] [d] [line 6, size 32, align 32, offset 96] [from int]
!15 = metadata !{metadata !"0xd\00e\007\0032\0032\00128\000", metadata !1, metadata !9, metadata !8} ; [ DW_TAG_member ] [e] [line 7, size 32, align 32, offset 128] [from int]
!16 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}
!17 = metadata !{metadata !"0x101\00f\0016777229\008192", metadata !4, metadata !5, metadata !9} ; [ DW_TAG_arg_variable ] [f] [line 13]
!18 = metadata !{i32 13, i32 0, metadata !4, null}
!19 = metadata !{i32 16, i32 0, metadata !4, null}
!20 = metadata !{i32 1, metadata !"Debug Info Version", i32 2}