# RUN: llc %s -o - -experimental-debug-variable-locations=true \ # RUN: -run-pass=livedebugvalues \ # RUN: | FileCheck %s --implicit-check-not=DBG_VALUE # RUN: llc %s -o - -experimental-debug-variable-locations=true \ # RUN: -start-before=livedebugvalues -filetype=obj \ # RUN: | llvm-dwarfdump - | FileCheck %s --check-prefix=DWARF # # LLVM can produce DIExpressions that convert from one value of arbitrary size # to another. This is normally fine, however that means the value for a # variable tracked in instruction referencing might not be the same size as the # variable itself. # # This becomes a problem when values move onto the stack and we emit # DW_OP_deref: there is no information about how large a value the consumer # should load from the stack. The convention today appears to be the size of # the variable, and as a result if you have a value that's smaller than the # variable size, extra information is loaded onto the DWARF expression stack. # This then appears as a false variable value to the consumer. # # In this test, there are various scenarios to test where the size of the value # needs to reach the expression emitter in LiveDebugValues. However, there are # even more scenarios to consider where the value is in a spill slot, and: # * The value is larger than the variable, the same, or smaller, # * The variable is a normal scalar, or a fragment, # * There is a DW_OP_stack_value in the expression, or not # That gives us twelve situations to consider, and the easiest way to confirm # correctness is to write them all out. The final DWARF expressions to # produce are: # * No stack value, # * Scalar (32 bits), # * Larger value (64 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_stack_value # * Same value (32 bits) # DW_OP_breg7 RSP-8 # * Smaller value (8 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_stack_value # * Fragment (32 bits) # * Larger value (64 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_stack_value, DW_OP_piece 0x4 # * Same value (32 bits) # DW_OP_breg7 RSP-8, DW_OP_piece 0x4 # * Smaller value (8 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_stack_value, DW_OP_piece 0x4 # * Stack value (imagine there was some arithmetic on the stack before the # DW_OP_stack_value opcode), # * Scalar (32 bits), # * Larger value (64 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_stack_value # * Same value (32 bits) # DW_OP_breg7 RSP-8, DW_OP_deref, DW_OP_stack_value # * Smaller value (8 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_stack_value # * Fragment (32 bits) # * Larger value (64 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_stack_value, DW_OP_piece 0x4 # * Same value (32 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x4, DW_OP_stack_value, DW_OP_piece 0x4 # * Smaller value (8 bits) # DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_stack_value, DW_OP_piece 0x4 # # The outlier from the pattern is (Stack value, Fragment, Same value size): we # put a DW_OP_deref_size in where a DW_OP_deref could have sufficied. However, # if we used DW_OP_deref, it would force the consumer to derive the deref size # from the DW_OP_piece, which is un-necessarily hard. ## Capture variable num, # CHECK-DAG: ![[VARNUM:[0-9]+]] = !DILocalVariable(name: "flannel", # CHECK-DAG: ![[VARNUM2:[0-9]+]] = !DILocalVariable(name: "shoes", # DWARF: DW_TAG_variable # DWARF-NEXT: DW_AT_location ## Defined in register, spilt to stack. # DWARF-NEXT: DW_OP_breg0 RAX+0, DW_OP_constu 0xff, DW_OP_and, DW_OP_convert (0x00000026) "DW_ATE_signed_8", DW_OP_convert (0x0000002a) "DW_ATE_signed_32", DW_OP_stack_value # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_convert (0x00000026) "DW_ATE_signed_8", DW_OP_convert (0x0000002a) "DW_ATE_signed_32", DW_OP_stack_value ## Defined on stack. # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_convert (0x00000026) "DW_ATE_signed_8", DW_OP_convert (0x0000002a) "DW_ATE_signed_32", DW_OP_stack_value ## DBG_PHI that moves to stack. # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_stack_value ## DBG_PHI of stack with size. # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x2, DW_OP_stack_value ## Followed by scalar / no-stack-value locations with various sizes. # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_stack_value # DWARF-NEXT: DW_OP_breg7 RSP-8 # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_stack_value ## scalar / stack value with various sizes. # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_lit1, DW_OP_plus, DW_OP_stack_value # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref, DW_OP_lit1, DW_OP_plus, DW_OP_stack_value # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_lit1, DW_OP_plus, DW_OP_stack_value) # DWARF: DW_AT_name ("flannel") # Variable with fragments. # DWARF: DW_TAG_variable # DWARF-NEXT: DW_AT_location ## Scalar / no-stack-value locations with various sizes. # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_stack_value, DW_OP_piece 0x4 # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_piece 0x4 # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_stack_value, DW_OP_piece 0x4 ## Scalar / stack value with various sizes. # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x8, DW_OP_lit1, DW_OP_plus, DW_OP_stack_value, DW_OP_piece 0x4 # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x4, DW_OP_lit1, DW_OP_plus, DW_OP_stack_value, DW_OP_piece 0x4 # DWARF-NEXT: DW_OP_breg7 RSP-8, DW_OP_deref_size 0x1, DW_OP_lit1, DW_OP_plus, DW_OP_stack_value, DW_OP_piece 0x4) # DWARF: DW_AT_name ("shoes") --- | ; ModuleID = 'missingvar.ll' source_filename = "a" target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" define linkonce_odr void @_ZNSt5dequeIPN4llvm4LoopESaIS2_EE13_M_insert_auxESt15_Deque_iteratorIS2_RS2_PS2_EmRKS2_() local_unnamed_addr align 2 !dbg !3 { entry: call void @llvm.dbg.value(metadata i32 0, metadata !8, metadata !DIExpression()), !dbg !7 call void @llvm.dbg.value(metadata i32 0, metadata !10, metadata !DIExpression()), !dbg !7 ret void } declare void @llvm.dbg.value(metadata, metadata, metadata) !llvm.module.flags = !{!0, !9} !llvm.dbg.cu = !{!1} !0 = !{i32 2, !"Debug Info Version", i32 3} !1 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !2, producer: "beards", isOptimized: true, runtimeVersion: 4, emissionKind: FullDebug) !2 = !DIFile(filename: "bees.cpp", directory: "") !3 = distinct !DISubprogram(name: "nope", scope: !2, file: !2, line: 1, type: !4, spFlags: DISPFlagDefinition, unit: !1) !4 = !DISubroutineType(types: !5) !5 = !{!6} !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) !7 = !DILocation(line: 1, scope: !3) !8 = !DILocalVariable(name: "flannel", scope: !3, type: !6) !9 = !{i32 2, !"Dwarf Version", i32 5} !10 = !DILocalVariable(name: "shoes", scope: !3, type: !11) !11 = !DIBasicType(name: "long", size: 64, encoding: DW_ATE_signed) ... --- name: _ZNSt5dequeIPN4llvm4LoopESaIS2_EE13_M_insert_auxESt15_Deque_iteratorIS2_RS2_PS2_EmRKS2_ alignment: 16 tracksRegLiveness: true liveins: - { reg: '$rdi' } - { reg: '$rsi' } - { reg: '$rdx' } frameInfo: stackSize: 48 offsetAdjustment: -48 maxAlignment: 8 maxCallFrameSize: 0 cvBytesOfCalleeSavedRegisters: 48 fixedStack: - { id: 0, type: spill-slot, offset: -56, size: 8, alignment: 8, callee-saved-register: '$rbx' } - { id: 1, type: spill-slot, offset: -48, size: 8, alignment: 16, callee-saved-register: '$r12' } - { id: 2, type: spill-slot, offset: -40, size: 8, alignment: 8, callee-saved-register: '$r13' } - { id: 3, type: spill-slot, offset: -32, size: 8, alignment: 16, callee-saved-register: '$r14' } - { id: 4, type: spill-slot, offset: -24, size: 8, alignment: 8, callee-saved-register: '$r15' } - { id: 5, type: spill-slot, offset: -16, size: 8, alignment: 16, callee-saved-register: '$rbp' } stack: - { id: 0, type: spill-slot, offset: -64, size: 8, alignment: 8 } machineFunctionInfo: {} body: | bb.0.entry: liveins: $rdi, $rdx, $rsi, $rbp, $r15, $r14, $r13, $r12, $rbx ; CHECK-LABEL: bb.0.entry: ;; PART ONE: For this first block of tests, check that information about ;; the size of the value on the stack makes it through to the expression. $al = MOV8ri 0, debug-instr-number 1, debug-location !7 DBG_INSTR_REF 1, 0, !8, !DIExpression(DW_OP_LLVM_convert, 8, DW_ATE_signed, DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value), debug-location !7 ; CHECK: DBG_VALUE $al, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_LLVM_convert, 8, DW_ATE_signed, ; CHECK-SAME : DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value) MOV8mr $rsp, 1, $noreg, -8, $noreg, renamable $al :: (store 1 into %stack.0) ;; Clobber to force variable location onto stack. We should use a ;; deref_size 1 because the value is smaller than the variable. $al = MOV8ri 0, debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, ; CHECK-SAME: DW_OP_deref_size, 1, DW_OP_LLVM_convert, 8, DW_ATE_signed, ; CHECK-SAME: DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value), ; Terminate the current variable location, DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg, ![[VARNUM]], !DIExpression() ;; Try again, but with the value originating on the stack, to ensure that ;; we can find its size. It should be deref_size 1 again. INC8m $rsp, 1, $noreg, 4, $noreg, implicit-def dead $eflags, debug-instr-number 2, debug-location !7 :: (store (s8) into %stack.0) DBG_INSTR_REF 2, 1000000, !8, !DIExpression(DW_OP_LLVM_convert, 8, DW_ATE_signed, DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, ; CHECK-SAME: DW_OP_deref_size, 1, DW_OP_LLVM_convert, 8, DW_ATE_signed, ; CHECK-SAME: DW_OP_LLVM_convert, 32, DW_ATE_signed, DW_OP_stack_value), $eax = MOV32ri 0, debug-location !7 ;; How about DBG_PHIs? The size of the value is communicated by the register ;; size, or an extra DBG_PHI operand, and that should feed through into the ;; decision of whether to deref_size or not. DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg $al = MOV8ri 0, debug-location !7 DBG_PHI $al, 7 MOV32mr $rsp, 1, $noreg, -8, $noreg, renamable $eax :: (store 4 into %stack.0) $eax = MOV32ri 0, debug-location !7 DBG_INSTR_REF 7, 0, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 1, DW_OP_stack_value) $eax = MOV32ri 0, debug-location !7 ;; And for when the DBG_PHI specifies a stack size... DBG_PHI %stack.0, 8, 16 DBG_INSTR_REF 8, 0, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 2, DW_OP_stack_value) $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg DBG_VALUE $noreg, $noreg, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; PART TWO: test the twelve kinds of location expression mentioned in the ;; opening comment of this test, in that order. Please update the opening ;; comment, these lines and the DWARF check lines at the same time. ;; In each test we'll state a location, give it an instruction to cover, ;; and then terminate it. ;; Scalar (32), Large value (64), no stack value, $rax = MOV64ri 0, debug-instr-number 10, debug-location !7 MOV64mr $rsp, 1, $noreg, -8, $noreg, renamable $rax :: (store 8 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 10, 0, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 8, DW_OP_stack_value), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Scalar (32), Same value size (32), no stack value, $eax = MOV32ri 0, debug-instr-number 11, debug-location !7 MOV32mr $rsp, 1, $noreg, -8, $noreg, renamable $eax :: (store 4 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 11, 0, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $rsp, 0, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Scalar (32), Smaller value (8), no stack value, $al = MOV8ri 0, debug-instr-number 12, debug-location !7 MOV8mr $rsp, 1, $noreg, -8, $noreg, renamable $al :: (store 1 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 12, 0, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 1, DW_OP_stack_value), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Fragment (32), Larger value (64), no stack value, $rax = MOV64ri 0, debug-instr-number 13, debug-location !7 MOV64mr $rsp, 1, $noreg, -8, $noreg, renamable $rax :: (store 8 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 13, 0, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM2]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 8, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Fragment (32), Same value size (32), no stack value, $eax = MOV32ri 0, debug-instr-number 14, debug-location !7 MOV32mr $rsp, 1, $noreg, -8, $noreg, renamable $eax :: (store 4 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 14, 0, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $rsp, 0, ![[VARNUM2]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_LLVM_fragment, 0, 32), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Fragment (32), Smaller value (8), no stack value, $al = MOV8ri 0, debug-instr-number 15, debug-location !7 MOV8mr $rsp, 1, $noreg, -8, $noreg, renamable $al :: (store 1 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 15, 0, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM2]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 1, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Scalar (32), Large value (64), with stack value, $rax = MOV64ri 0, debug-instr-number 16, debug-location !7 MOV64mr $rsp, 1, $noreg, -8, $noreg, renamable $rax :: (store 8 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 16, 0, !8, !DIExpression(DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 8, DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Scalar (32), Same value size (32), no stack value, $eax = MOV32ri 0, debug-instr-number 17, debug-location !7 MOV32mr $rsp, 1, $noreg, -8, $noreg, renamable $eax :: (store 4 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 17, 0, !8, !DIExpression(DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref, DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Scalar (32), Smaller value (8), no stack value, $al = MOV8ri 0, debug-instr-number 18, debug-location !7 MOV8mr $rsp, 1, $noreg, -8, $noreg, renamable $al :: (store 1 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 18, 0, !8, !DIExpression(DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 1, DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !8, !DIExpression(), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Fragment (32), Larger value (64), no stack value, $rax = MOV64ri 0, debug-instr-number 19, debug-location !7 MOV64mr $rsp, 1, $noreg, -8, $noreg, renamable $rax :: (store 8 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 19, 0, !10, !DIExpression(DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM2]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 8, DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Fragment (32), Same value size (32), no stack value, $eax = MOV32ri 0, debug-instr-number 20, debug-location !7 MOV32mr $rsp, 1, $noreg, -8, $noreg, renamable $eax :: (store 4 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 20, 0, !10, !DIExpression(DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM2]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 4, DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg ;; Fragment (32), Smaller value (8), no stack value, $al = MOV8ri 0, debug-instr-number 21, debug-location !7 MOV8mr $rsp, 1, $noreg, -8, $noreg, renamable $al :: (store 1 into %stack.0) $rax = MOV64ri 0, debug-location !7 DBG_INSTR_REF 21, 0, !10, !DIExpression(DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $rsp, $noreg, ![[VARNUM2]], ; CHECK-SAME: !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_deref_size, 1, DW_OP_constu, 1, DW_OP_plus, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32), $eax = MOV32ri 0, debug-location !7 DBG_VALUE $noreg, $noreg, !10, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !7 ; CHECK: DBG_VALUE $noreg, $noreg RET64 0, debug-location !7 ...