reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155
  156
  157
  158
  159
  160
  161
  162
  163
  164
  165
  166
  167
  168
  169
  170
  171
  172
  173
  174
  175
  176
  177
  178
; Test the behavior of GlobalDCE in conjunction with comdats.
;
; RUN: opt < %s -globaldce -S | FileCheck %s

; First test checks that if one function in a comdat group is used, both other
; functions and other globals even if unused will be preserved.
$test1_c = comdat any
; CHECK: $test1_c = comdat any

; Second test checks that if one function in a comdat group is used, both other
; functions and other globals even if unused will be preserved.
$test2_c = comdat any
; CHECK: $test2_c = comdat any

; Third test checks that calling a function in a comdat group with an alias
; preserves the alias.
$test3_c = comdat any
; CHECK: $test3_c = comdat any

; Fourth test checks that calling an alias in a comdat group with a function
; preserves the function. (This is the trivial case as the alias uses the
; function.)
$test4_c = comdat any
; CHECK: $test4_c = comdat any

; Fifth test checks that calling a function in a comdat group that is used as
; the resolver of an ifunc doesn't preserve that ifunc. ifunc symbols don't
; participate in the comdat group of their resolver function as they are
; considered separate objects.
$test5_c = comdat any
; CHECK: $test5_c = comdat any

; Sixth test checks that calling an ifunc whose resolver is in a comdat group
; preserves the resolver. This is the trivial case as the ifunc uses the
; resolver.
$test6_c = comdat any
; CHECK: $test6_c = comdat any

; Seventh test checks that we can eliminate a comdat when it has only one dead function participant.
$test7_c = comdat any
; CHECK-NOT: $test7_c = comdat any

; Eighth test checks that we can eliminate a comdat when it has only one dead global participant.
$test8_c = comdat any
; CHECK-NOT: $test8_c = comdat any

; Ninth test checks that we can eliminate a comdat when there are multiple
; dead participants.
$test9_c = comdat any
; CHECK-NOT: $test9_c = comdat any

; Tenth test checks that we can eliminate a comdat when it has multiple
; participants that form internal cyclic uses but are never used externally and
; thus the entire ifunc can safely be eliminated.
$test10_c = comdat any
; CHECK-NOT: $test10_c = comdat any

@test1_gv = linkonce_odr unnamed_addr global i32 42, comdat($test1_c)
; CHECK: @test1_gv = linkonce_odr unnamed_addr global

@test2_used = linkonce_odr unnamed_addr global i32 42, comdat($test2_c)
; CHECK: @test2_used = linkonce_odr unnamed_addr global

@test2_gv = linkonce_odr unnamed_addr global i32 42, comdat($test2_c)
; CHECK: @test2_gv = linkonce_odr unnamed_addr global

@test8_gv = linkonce_odr unnamed_addr global i32 42, comdat($test8_c)
; CHECK-NOT: @test8_gv

@test9_gv = linkonce_odr unnamed_addr global i32 42, comdat($test9_c)
; CHECK-NOT: @test9_gv

@test10_gv = linkonce_odr unnamed_addr global void ()* @test10_f, comdat($test10_c)
; CHECK-NOT: @test10_gv

@test3_a = linkonce_odr unnamed_addr alias void (), void ()* @test3_f
; CHECK: @test3_a = linkonce_odr unnamed_addr alias

@test4_a = linkonce_odr unnamed_addr alias void (), void ()* @test4_f
; CHECK: @test4_a = linkonce_odr unnamed_addr alias

@test10_a = linkonce_odr unnamed_addr alias void (), void ()* @test10_g
; CHECK-NOT: @test10_a

@test5_if = linkonce_odr ifunc void (), void ()* ()* @test5_f
; CHECK-NOT: @test5_if

@test6_if = linkonce_odr ifunc void (), void ()* ()* @test6_f
; CHECK: @test6_if = linkonce_odr ifunc

; This function is directly used and so cannot be eliminated.
define linkonce_odr void @test1_used() comdat($test1_c) {
; CHECK: define linkonce_odr void @test1_used()
entry:
  ret void
}

define linkonce_odr void @test1_f() comdat($test1_c) {
; CHECK: define linkonce_odr void @test1_f()
entry:
  ret void
}

; Now test that a function, global variable, alias, and ifunc in the same
; comdat are kept.
define linkonce_odr void @test2_f() comdat($test2_c) {
; CHECK: define linkonce_odr void @test2_f()
entry:
  ret void
}

define linkonce_odr void @test3_f() comdat($test3_c) {
; CHECK: define linkonce_odr void @test3_f()
entry:
  ret void
}

define linkonce_odr void @test4_f() comdat($test4_c) {
; CHECK: define linkonce_odr void @test4_f()
entry:
  ret void
}

declare void @test_external()

define linkonce_odr void ()* @test5_f() comdat($test5_c) {
; CHECK: define linkonce_odr void ()* @test5_f()
entry:
  ret void ()* @test_external
}

define linkonce_odr void ()* @test6_f() comdat($test6_c) {
; CHECK: define linkonce_odr void ()* @test6_f()
entry:
  ret void ()* @test_external
}

define linkonce_odr void @test7_f() comdat($test7_c) {
; CHECK-NOT: @test7_f
entry:
  ret void
}

define linkonce_odr void @test9_f() comdat($test9_c) {
; CHECK-NOT: @test9_f
entry:
  ret void
}

define linkonce_odr void @test10_f() comdat($test10_c) {
; CHECK-NOT: @test10_f
entry:
  %gv = load void ()*, void ()** @test10_gv
  call void @test10_a()
  ret void
}

define linkonce_odr void @test10_g() comdat($test10_c) {
; CHECK-NOT: @test10_g
entry:
  call void @test10_f()
  ret void
}


; An external function to pin as "used" various things above that shouldn't be
; eliminated.
define void @external_user() {
  call void @test1_used()
  %gv = load i32, i32* @test2_used

  call void @test3_f()
  call void @test4_a()

  %fptr = call void() *@test5_f()
  call void @test6_if()
  ret void
}