bolt/test/X86/split-landing-pad.s

   1 ## This test reproduces the case where C++ exception handling is used and split
   2 ## function optimization is enabled. In particular, function foo is splitted
   3 ## to two fragments:
   4 ##    foo: contains 2 try blocks, which invokes bar to throw exception
   5 ##    foo.cold.1: contains 2 corresponding catch blocks (landing pad)
   6 ##
   7 ## Similar to split jump table, split landing pad target to different fragment.
   8 ## This test is written to ensure BOLT safely handle these targets, e.g., by
   9 ## marking them as non-simple.
  10 ##
  11 ## Steps to write this test:
  12 ## - Create a copy of Inputs/src/unreachable.cpp
  13 ## - Simplify bar(), focus on throw an exception
  14 ## - Create the second switch case in foo() to have multiple landing pads
  15 ## - Compile with clang++ to .s
  16 ## - Move landing pad code from foo to foo.cold.1
  17 ## - Ensure that all landing pads can be reached normally
  18 ##
  19 ## Additional details:
  20 ## .gcc_except_table specify the landing pads for try blocks
  21 ##    LPStart = 255 (omit), which means LPStart = foo start
  22 ## Landing pads .Ltmp2 and .Ltmp5 in call site record are offset to foo start.
  23
  24
  25 # REQUIRES: system-linux
  26 # RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %s -o %t.o
  27 # RUN: %clang++ %cxxflags %t.o -o %t.exe -Wl,-q
  28 # RUN: llvm-bolt -v=3 %t.exe -o %t.out 2>&1 | FileCheck %s
  29
  30 # CHECK: BOLT-WARNING: Ignoring foo
  31 # CHECK: BOLT-WARNING: Ignoring foo.cold.1
  32 # CHECK: BOLT-WARNING: skipped 2 functions due to cold fragments
  33
  34         .text
  35         .globl  bar                             # -- Begin function bar
  36         .p2align        4, 0x90
  37         .type   bar,@function
  38 bar:                                    # @bar
  39         .cfi_startproc
  40 # %bb.0:                                # %entry
  41         pushq   %rbp
  42         .cfi_def_cfa_offset 16
  43         .cfi_offset %rbp, -16
  44         movq    %rsp, %rbp
  45         .cfi_def_cfa_register %rbp
  46         subq    $16, %rsp
  47         movq    %rdi, -8(%rbp)
  48         cmpq    $34, -8(%rbp)
  49         jne     .LBB0_2
  50 # %bb.1:                                # %if.then
  51         movl    $4, %edi
  52         callq   __cxa_allocate_exception@PLT
  53         movq    %rax, %rdi
  54         movl    $0, (%rdi)
  55         movq    _ZTIi@GOTPCREL(%rip), %rsi
  56         xorl    %eax, %eax
  57         movl    %eax, %edx
  58         callq   __cxa_throw@PLT
  59 .LBB0_2:                                # %if.else
  60         movl    $8, %edi
  61         callq   __cxa_allocate_exception@PLT
  62         movq    %rax, %rdi
  63         movq    $0, (%rdi)
  64         movq    _ZTIDn@GOTPCREL(%rip), %rsi
  65         xorl    %eax, %eax
  66         movl    %eax, %edx
  67         callq   __cxa_throw@PLT
  68 .Lfunc_end0:
  69         .size   bar, .Lfunc_end0-bar
  70         .cfi_endproc
  71                                         # -- End function
  72         .globl  foo                             # -- Begin function foo
  73         .p2align        4, 0x90
  74         .type   foo,@function
  75 foo:                                    # @foo
  76 .Lfunc_begin0:
  77         .cfi_startproc
  78         .cfi_personality 155, DW.ref.__gxx_personality_v0
  79         .cfi_lsda 27, .Lexception0
  80 # %bb.0:                                # %entry
  81         pushq   %rbp
  82         .cfi_def_cfa_offset 16
  83         .cfi_offset %rbp, -16
  84         movq    %rsp, %rbp
  85         .cfi_def_cfa_register %rbp
  86         subq    $48, %rsp
  87         movq    %rdi, -16(%rbp)
  88         movq    -16(%rbp), %rdi
  89 .Ltmp0:
  90         callq   bar
  91 .Ltmp1:
  92         jmp     .LBB1_1
  93 .LBB1_1:                                # %invoke.cont
  94         jmp     .LBB1_5
  95 .LBB1_5:                                # %try.cont
  96         movq    -16(%rbp), %rdi
  97         addq    $34, %rdi
  98 .Ltmp3:
  99         callq   bar
 100 .Ltmp4:
 101         jmp     .LBB1_6
 102 .LBB1_6:                                # %invoke.cont2
 103         jmp     .LBB1_10
 104 .LBB1_10:                               # %try.cont8
 105         movq    $0, -8(%rbp)
 106 .LBB1_11:                               # %return
 107         movq    -8(%rbp), %rax
 108         addq    $48, %rsp
 109         popq    %rbp
 110         .cfi_def_cfa %rsp, 8
 111         retq
 112 .LBB1_12:                               # %eh.resume
 113         .cfi_def_cfa %rbp, 16
 114         movq    -24(%rbp), %rdi
 115         callq   _Unwind_Resume@PLT
 116 .Lfunc_end1:
 117         .size   foo, .Lfunc_end1-foo
 118         .cfi_endproc
 119         .section        .gcc_except_table,"a",@progbits
 120         .p2align        2
 121 GCC_except_table1:
 122 .Lexception0:
 123         .byte   255                             # @LPStart Encoding = omit
 124         .byte   155                             # @TType Encoding = indirect pcrel sdata4
 125         .uleb128 .Lttbase0-.Lttbaseref0
 126 .Lttbaseref0:
 127         .byte   1                               # Call site Encoding = uleb128
 128         .uleb128 .Lcst_end0-.Lcst_begin0
 129 .Lcst_begin0:
 130         .uleb128 .Ltmp0-.Lfunc_begin0           # >> Call Site 1 <<
 131         .uleb128 .Ltmp1-.Ltmp0                  #   Call between .Ltmp0 and .Ltmp1
 132         .uleb128 .Ltmp2-.Lfunc_begin0           #     jumps to .Ltmp2
 133         .byte   1                               #   On action: 1
 134         .uleb128 .Ltmp1-.Lfunc_begin0           # >> Call Site 2 <<
 135         .uleb128 .Ltmp3-.Ltmp1                  #   Call between .Ltmp1 and .Ltmp3
 136         .byte   0                               #     has no landing pad
 137         .byte   0                               #   On action: cleanup
 138         .uleb128 .Ltmp3-.Lfunc_begin0           # >> Call Site 3 <<
 139         .uleb128 .Ltmp4-.Ltmp3                  #   Call between .Ltmp3 and .Ltmp4
 140         .uleb128 .Ltmp5-.Lfunc_begin0           #     jumps to .Ltmp5
 141         .byte   1                               #   On action: 1
 142         .uleb128 .Ltmp4-.Lfunc_begin0           # >> Call Site 4 <<
 143         .uleb128 .Lfunc_end1-.Ltmp4             #   Call between .Ltmp4 and .Lfunc_end1
 144         .byte   0                               #     has no landing pad
 145         .byte   0                               #   On action: cleanup
 146 .Lcst_end0:
 147         .byte   1                               # >> Action Record 1 <<
 148                                         #   Catch TypeInfo 1
 149         .byte   0                               #   No further actions
 150         .p2align        2
 151                                         # >> Catch TypeInfos <<
 152 .Ltmp6:                                 # TypeInfo 1
 153         .long   .L_ZTIi.DW.stub-.Ltmp6
 154 .Lttbase0:
 155         .p2align        2
 156                                         # -- End function
 157
 158
 159         .text
 160         .globl  foo.cold.1              # -- Begin function foo.cold.1
 161         .p2align        4, 0x90
 162         .type   foo.cold.1,@function
 163 foo.cold.1:                                    # @foo.cold.1
 164 .Lfunc_begin3:
 165         .cfi_startproc
 166 .Ltmp2:
 167         movq    %rax, %rcx
 168         movl    %edx, %eax
 169         movq    %rcx, -24(%rbp)
 170         movl    %eax, -28(%rbp)
 171 # %bb.3:                                # %catch.dispatch
 172         movl    -28(%rbp), %eax
 173         movl    $1, %ecx
 174         cmpl    %ecx, %eax
 175         jne     .LBB1_12
 176 # %bb.4:                                # %catch
 177         movq    -24(%rbp), %rdi
 178         callq   __cxa_begin_catch@PLT
 179         movl    (%rax), %eax
 180         movl    %eax, -32(%rbp)
 181         movq    $0, -8(%rbp)
 182         callq   __cxa_end_catch@PLT
 183         jmp     .LBB1_11
 184 .Ltmp5:
 185         movq    %rax, %rcx
 186         movl    %edx, %eax
 187         movq    %rcx, -24(%rbp)
 188         movl    %eax, -28(%rbp)
 189 # %bb.8:                                # %catch.dispatch3
 190         movl    -28(%rbp), %eax
 191         movl    $1, %ecx
 192         cmpl    %ecx, %eax
 193         jne     .LBB1_12
 194 # %bb.9:                                # %catch6
 195         movq    -24(%rbp), %rdi
 196         callq   __cxa_begin_catch@PLT
 197         movl    (%rax), %eax
 198         movl    %eax, -36(%rbp)
 199         movq    $0, -8(%rbp)
 200         callq   __cxa_end_catch@PLT
 201         jmp     .LBB1_11
 202 .Lfunc_end3:
 203         .size   foo.cold.1, .Lfunc_end3-foo.cold.1
 204         .cfi_endproc
 205
 206
 207         .text
 208         .globl  main                            # -- Begin function main
 209         .p2align        4, 0x90
 210         .type   main,@function
 211 main:                                   # @main
 212         .cfi_startproc
 213 # %bb.0:                                # %entry
 214         pushq   %rbp
 215         .cfi_def_cfa_offset 16
 216         .cfi_offset %rbp, -16
 217         movq    %rsp, %rbp
 218         .cfi_def_cfa_register %rbp
 219         subq    $16, %rsp
 220         movl    $0, -4(%rbp)
 221         movl    %edi, -8(%rbp)
 222         movq    %rsi, -16(%rbp)
 223         xorl    %eax, %eax
 224         movl    %eax, %edi
 225         callq   foo
 226                                         # kill: def $eax killed $eax killed $rax
 227         addq    $16, %rsp
 228         popq    %rbp
 229         .cfi_def_cfa %rsp, 8
 230         retq
 231 .Lfunc_end2:
 232         .size   main, .Lfunc_end2-main
 233         .cfi_endproc
 234                                         # -- End function
 235         .data
 236         .p2align        3
 237 .L_ZTIi.DW.stub:
 238         .quad   _ZTIi
 239         .hidden DW.ref.__gxx_personality_v0
 240         .weak   DW.ref.__gxx_personality_v0
 241         .section        .data.DW.ref.__gxx_personality_v0,"aGw",@progbits,DW.ref.__gxx_personality_v0,comdat
 242         .p2align        3
 243         .type   DW.ref.__gxx_personality_v0,@object
 244         .size   DW.ref.__gxx_personality_v0, 8
 245 DW.ref.__gxx_personality_v0:
 246         .quad   __gxx_personality_v0
 247         .section        ".note.GNU-stack","",@progbits
 248         .addrsig
 249         .addrsig_sym bar
 250         .addrsig_sym __cxa_allocate_exception
 251         .addrsig_sym __cxa_throw
 252         .addrsig_sym foo
 253         .addrsig_sym __gxx_personality_v0
 254         .addrsig_sym __cxa_begin_catch
 255         .addrsig_sym __cxa_end_catch
 256         .addrsig_sym _Unwind_Resume
 257         .addrsig_sym _ZTIi
 258         .addrsig_sym _ZTIDn
 259         .addrsig_sym foo.cold.1
 260         .addrsig_sym __cxa_begin_catch
 261         .addrsig_sym __cxa_end_catch