File: dbg-value-reg-stackify.mir

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# RUN: llc -run-pass wasm-reg-stackify %s -o - | FileCheck %s

# Tests for DBG_VALUE hanlding in RegStackify + DebugValueManager

--- |
  target triple = "wasm32-unknown-unknown"

  declare void @use(i32)
  declare void @use_2(i32, i32)

  define void @sink_simple() !dbg !6 {
    call void @llvm.dbg.value(metadata i32 0, metadata !5, metadata !DIExpression()), !dbg !10
    call void @llvm.dbg.value(metadata i32 0, metadata !11, metadata !DIExpression()), !dbg !10
    call void @llvm.dbg.value(metadata i32 0, metadata !12, metadata !DIExpression()), !dbg !10
    call void @llvm.dbg.value(metadata i32 0, metadata !13, metadata !DIExpression()), !dbg !10
    ret void
  }
  define void @sink_non_consecutive() !dbg !14 {
    unreachable
  }
  define void @dont_sink_above_def() !dbg !15 {
    unreachable
  }
  define void @sink_to_same_place() !dbg !16 {
    unreachable
  }
  define void @cannot_sink_across_same_variable() !dbg !17 {
    unreachable
  }
  define void @cannot_sink_across_same_variable2() !dbg !18 {
    unreachable
  }
  define void @can_sink_across_same_variable_with_same_const() !dbg !19 {
    unreachable
  }
  define void @sink_multiple_defs() !dbg !20 {
    unreachable
  }
  define void @clone_same_bb() !dbg !21 {
    unreachable
  }
  define void @clone_different_bb() !dbg !22 {
    unreachable
  }
  define void @tee_with_two_use_insts() !dbg !23 {
    unreachable
  }
  define void @tee_with_one_inst_with_two_uses() !dbg !24 {
    unreachable
  }
  declare void @llvm.dbg.value(metadata, metadata, metadata)

  !llvm.dbg.cu = !{!0}
  !llvm.module.flags = !{!2, !3, !4}

  ; Note the current mapping variable metadata and their names, which we will
  ; use in all functions in ths file:
  ; - "var_a" / VAR_A: !5
  ; - "var_b" / VAR_B: !11
  ; - "var_c" / VAR_C: !12
  ; - "var_d" / VAR_D: !13
  ; We will use VAR_? in the CHECK lines for robustness in case of metadata
  ; renumbering, but currently in mir tests we cannot use variable names like
  ; "var_a" directly in the input, which can be confusing to read.

  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, emissionKind: FullDebug)
  !1 = !DIFile(filename: "test.c", directory: "")
  !2 = !{i32 7, !"Dwarf Version", i32 5}
  !3 = !{i32 2, !"Debug Info Version", i32 3}
  !4 = !{i32 1, !"wchar_size", i32 4}
  !5 = !DILocalVariable(name: "var_a", scope: !6, file: !1, line: 2, type: !9)
  ; CHECK: ![[VAR_A:[0-9]+]] = !DILocalVariable(name: "var_a"
  !6 = distinct !DISubprogram(name: "sink_simple", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !7 = !DISubroutineType(types: !8)
  !8 = !{null}
  !9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
  !10 = !DILocation(line: 0, scope: !6)
  !11 = !DILocalVariable(name: "var_b", scope: !6, file: !1, line: 2, type: !9)
  ; CHECK: ![[VAR_B:[0-9]+]] = !DILocalVariable(name: "var_b"
  !12 = !DILocalVariable(name: "var_c", scope: !6, file: !1, line: 2, type: !9)
  ; CHECK: ![[VAR_C:[0-9]+]] = !DILocalVariable(name: "var_c"
  !13 = !DILocalVariable(name: "var_d", scope: !6, file: !1, line: 2, type: !9)
  ; CHECK: ![[VAR_D:[0-9]+]] = !DILocalVariable(name: "var_d"
  !14 = distinct !DISubprogram(name: "sink_non_consecutive", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !15 = distinct !DISubprogram(name: "dont_sink_above_def", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !16 = distinct !DISubprogram(name: "sink_to_same_place", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !17 = distinct !DISubprogram(name: "cannot_sink_across_same_variable", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !18 = distinct !DISubprogram(name: "cannot_sink_across_same_variable2", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !19 = distinct !DISubprogram(name: "can_sink_across_same_variable_with_same_const", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !20 = distinct !DISubprogram(name: "sink_multiple_defs", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !21 = distinct !DISubprogram(name: "clone_same_bb", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !22 = distinct !DISubprogram(name: "clone_different_bb", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !23 = distinct !DISubprogram(name: "tee_with_two_use_insts", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
  !24 = distinct !DISubprogram(name: "tee_with_one_inst_with_two_uses", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
...

---
# A simple sinking example.
# '%0 = CONST_I32 1' will sink to the place before 'CALL %use', and the two
# DBG_VALUEs will sink with it, leaving the original DBG_VALUEs to be set to
# undef (= DBG_VALUE $noreg).
# CHECK-LABEL: name: sink_simple
name: sink_simple
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# Sinking when DBG_VALUEs are non-consecutive.
# '%0 = CONST_I32 1' will sink to the place before 'CALL %use', and the two
# DBG_VALUEs will sink with it, even though they are not consecutive. The
# original DBG_VALUEs will be set to undef.
# CHECK-LABEL: name: sink_non_consecutive
name: sink_non_consecutive
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# Only DBG_VALUEs following a def should be sunk together.
# '%0 = CONST_I32 1' will sink to the place before 'CALL %use', but the
# DBG_VALUE above it should be untouched.
# CHECK-LABEL: name: dont_sink_above_def
name: dont_sink_above_def
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    %0:i32 = CONST_I32 1, implicit-def $arguments
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      DBG_VALUE %0, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# A sink no-op case.
# '%0 = CONST_I32 1' will sink to the place before 'CALL %use', but it's already
# right before the CALL so it should be effectively a no-op. But currently
# sinking happens anyway so this will create unnecessary two undef DBG_VALUEs.
# This increases the number of DBG_VALUEs but doesn't hurt the coverage or
# generate incorrect debug info. TODO Improve this?
# CHECK-LABEL: name: sink_to_same_place
name: sink_to_same_place
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# A DBG_VALUE cannot be sunk across another DBG_VALUE that has the same
# DebugVariable, because it will reorder assignments.
# '%0 = CONST_I32 1' will sink to the place before 'CALL %use'. But from the two
# DBG_VALUEs following it, only the DBG_VALUE for "var_b" can sink with it,
# because there is another 'DBG_VALUE 10' for "var_a" in the middle.
# CHECK-LABEL: name: cannot_sink_across_same_variable
name: cannot_sink_across_same_variable
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    DBG_VALUE 10, $noreg, !5, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE 10, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# Another case in which a DBG_VALUE cannot be sunk across another DBG_VALUE with
# the same DebugVariable, because it will reorder assignments.
# '%0 = CONST_I32 1' will sink to the place before 'CALL %use'. But from the two
# DBG_VALUEs following it, only the DBG_VALUE for "var_b" can sink with it,
# because there is another 'DBG_VALUE %1, "var_a"' in the middle.
# CHECK-LABEL: name: cannot_sink_across_same_variable2
name: cannot_sink_across_same_variable2
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    %1:i32 = CONST_I32 2, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    DBG_VALUE %1:i32, $noreg, !5, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      %1:i32 = CONST_I32 2, implicit-def $arguments
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# There is a exception in which a DBG_VALUE can be sunk across another DBG_VALUE
# with the same DebugVariable: when the interfering DBG_VALUE refers to the same
# CONST_[I32/I64/F32/F64] instruction, in which case we don't reorder
# assignments.
#
# This is the same test with the previous one with one difference: %1 has the
# same CONST instruction with %0 'CONST_I32 1'. We can sink the DBG_VALUE for
# "var_a" here as well.
# CHECK-LABEL: name: can_sink_across_same_variable_with_same_const
name: can_sink_across_same_variable_with_same_const
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    %1:i32 = CONST_I32 1, implicit-def $arguments ; Same CONST_I32
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    DBG_VALUE %1:i32, $noreg, !5, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      %1:i32 = CONST_I32 1, implicit-def $arguments
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# Both %0 and %1 will be sunk to the place before ADD_I32. DBG_VALUEs associated
# with those two defs will be sunk as well, leaving the original DBG_VALUEs set
# to undef.
# CHECK-LABEL: name: sink_multiple_defs
name: sink_multiple_defs
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    %1:i32 = CONST_I32 2, implicit-def $arguments
    DBG_VALUE %1:i32, $noreg, !12, !DIExpression(), debug-location !10
    DBG_VALUE %1:i32, $noreg, !13, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    %2:i32 = ADD_I32 %0:i32, %1:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_C]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_D]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: %1:i32 = CONST_I32 2, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_C]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_D]], !DIExpression()
  ; CHECK-NEXT: dead %2:i32 = ADD_I32 %0, %1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# A simple cloning example.
# When processing the second 'CALL @use', because %0 has multiple uses, the def
# '%0 = CONST_I32 1' is cloned before the CALL, along with its DBG_VALUEs. And
# then when processing the first 'CALL @use', by that time %0 has only one use
# remaining, so it is just sink with the DBG_VALUEs, leaving the original
# DBG_VALUEs undef.
# CHECK-LABEL: name: clone_same_bb
name: clone_same_bb
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %0:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %0, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: %1:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# Cloning across different BBs.
# First, when bb.0's 'CALL @use' is procssed, '%0 = CONST_I32 1' and its
# DBG_VALUEs are cloned before the CALL. And when bb.1's 'CALL @use' is
# processed, '%0 = CONST_I32 1' and its DBG_VALUEs are cloned to bb.1 this time.
# Even though there are (previously cloned) DBG_VALUEs for "var_a" and "var_b"
# in the middle, it's fine because they point to the same 'CONST_I32 1'
# instruction.
# After the second cloning, the original '%0 = CONST_I32 1' is removed because
# it doesn't have any users anymore, leaving its original DBG_VALUEs as undef.
# CHECK-LABEL: name: clone_different_bb
name: clone_different_bb
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    successors: %bb.1
    liveins: $arguments
    %0:i32 = CONST_I32 1, implicit-def $arguments
    DBG_VALUE %0:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %0:i32, $noreg, !11, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %0:i32, implicit-def $arguments
    BR %bb.1, implicit-def $arguments

  ; CHECK:    bb.0:
  ; CHECK:      DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %1:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %1, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: BR %bb.1, implicit-def $arguments

  bb.1:
  ; predecessors: %bb.0
    CALL @use, %0:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:    bb.1:
  ; CHECK:      %2:i32 = CONST_I32 1, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %2, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %2, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %2, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# TEE conversion example.
# Convert this form:
#   Reg = INST ...        // Def
#   DBG_VALUE Reg, ...
#   INST ..., Reg, ...    // Insert
#   INST ..., Reg, ...
# to
#   DefReg = INST ...     // Def (to become the new Insert)
#   DBG_VALUE DefReg, ...
#   TeeReg, Reg = TEE_... DefReg
#   DBG_VALUE TeeReg, ...
#   INST ..., TeeReg, ... // Insert
#   INST ..., Reg, ...
# CHECK-LABEL: name: tee_with_two_use_insts
name: tee_with_two_use_insts
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = ARGUMENT_i32 0, implicit $arguments
    %1:i32 = ARGUMENT_i32 1, implicit $arguments
    %2:i32 = MUL_I32 %1:i32, %0:i32, implicit-def $arguments
    DBG_VALUE %2:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %2:i32, $noreg, !11, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use, %2:i32, implicit-def $arguments
    CALL @use, %2:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      %0:i32 = ARGUMENT_i32 0, implicit $arguments
  ; CHECK-NEXT: %1:i32 = ARGUMENT_i32 1, implicit $arguments
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %4:i32 = MUL_I32 %1, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %4, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %4, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: %3:i32, %2:i32 = TEE_I32 %4, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %3, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %3, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use, %3, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: CALL @use, %2, implicit-def $arguments
  ; CHECK-NEXT: RETURN implicit-def $arguments
...

---
# Another TEE conversion example. The previous example had two instructions
# that use a single register, whereas this has one instructions that has two
# same use operands. The resulting transformation is the same.
# CHECK-LABEL: name: tee_with_one_inst_with_two_uses
name: tee_with_one_inst_with_two_uses
liveins:
  - { reg: '$arguments' }
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $arguments
    %0:i32 = ARGUMENT_i32 0, implicit $arguments
    %1:i32 = ARGUMENT_i32 1, implicit $arguments
    %2:i32 = MUL_I32 %1:i32, %0:i32, implicit-def $arguments
    DBG_VALUE %2:i32, $noreg, !5, !DIExpression(), debug-location !10
    DBG_VALUE %2:i32, $noreg, !11, !DIExpression(), debug-location !10
    NOP implicit-def $arguments
    CALL @use_2, %2:i32, %2:i32, implicit-def $arguments
    RETURN implicit-def $arguments

  ; CHECK:      %0:i32 = ARGUMENT_i32 0, implicit $arguments
  ; CHECK-NEXT: %1:i32 = ARGUMENT_i32 1, implicit $arguments
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: NOP implicit-def $arguments
  ; CHECK-NEXT: %4:i32 = MUL_I32 %1, %0, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %4, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %4, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: %3:i32, %2:i32 = TEE_I32 %4, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: DBG_VALUE %3, $noreg, ![[VAR_A]], !DIExpression()
  ; CHECK-NEXT: DBG_VALUE %3, $noreg, ![[VAR_B]], !DIExpression()
  ; CHECK-NEXT: CALL @use_2, %3, %2, implicit-def $arguments, implicit-def $value_stack, implicit $value_stack
  ; CHECK-NEXT: RETURN implicit-def $arguments
...