bolt/test/runtime/X86/jt-confusion.s

   1 # REQUIRES: system-linux
   2
   3 # RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %s -o %t.o
   4 # RUN: llvm-strip --strip-unneeded %t.o
   5 # RUN: %clang %cflags -no-pie -nostartfiles -nostdlib -lc %t.o -o %t.exe -Wl,-q
   6
   7 # RUN: llvm-bolt %t.exe -o %t.exe.bolt --relocs=1 --lite=0
   8
   9 # RUN: %t.exe.bolt
  10
  11 ## Check that BOLT's jump table detection diffrentiates between
  12 ## __builtin_unreachable() targets and function pointers.
  13
  14 ## The test case was built from the following two source files and
  15 ## modiffied for standalone build. main became _start, etc.
  16 ## $ $(CC) a.c -O1 -S -o a.s
  17 ## $ $(CC) b.c -O0 -S -o b.s
  18
  19 ## a.c:
  20
  21 ## typedef int (*fptr)(int);
  22 ## void check_fptr(fptr, int);
  23 ##
  24 ## int foo(int a) {
  25 ##   check_fptr(foo, 0);
  26 ##   switch (a) {
  27 ##   default:
  28 ##     __builtin_unreachable();
  29 ##   case 0:
  30 ##     return 3;
  31 ##   case 1:
  32 ##     return 5;
  33 ##   case 2:
  34 ##     return 7;
  35 ##   case 3:
  36 ##     return 11;
  37 ##   case 4:
  38 ##     return 13;
  39 ##   case 5:
  40 ##     return 17;
  41 ##   }
  42 ##   return 0;
  43 ## }
  44 ##
  45 ## int main(int argc) {
  46 ##   check_fptr(main, 1);
  47 ##   return foo(argc);
  48 ## }
  49 ##
  50 ## const fptr funcs[2] = {foo, main};
  51
  52 ## b.c.:
  53
  54 ## typedef int (*fptr)(int);
  55 ## extern const fptr funcs[2];
  56 ##
  57 ## #define assert(C) { if (!(C)) (*(unsigned long long *)0) = 0; }
  58 ## void check_fptr(fptr f, int i) {
  59 ##   assert(f == funcs[i]);
  60 ## }
  61
  62
  63         .text
  64         .globl  foo
  65         .type   foo, @function
  66 foo:
  67 .LFB0:
  68         .cfi_startproc
  69         pushq   %rbx
  70         .cfi_def_cfa_offset 16
  71         .cfi_offset 3, -16
  72         movl    %edi, %ebx
  73         movl    $0, %esi
  74         movl    $foo, %edi
  75         call    check_fptr
  76         movl    %ebx, %ebx
  77         jmp     *.L4(,%rbx,8)
  78 .L8:
  79         movl    $5, %eax
  80         jmp     .L1
  81 .L7:
  82         movl    $7, %eax
  83         jmp     .L1
  84 .L6:
  85         movl    $11, %eax
  86         jmp     .L1
  87 .L5:
  88         movl    $13, %eax
  89         jmp     .L1
  90 .L3:
  91         movl    $17, %eax
  92         jmp     .L1
  93 .L10:
  94         movl    $3, %eax
  95 .L1:
  96         popq    %rbx
  97         .cfi_def_cfa_offset 8
  98         ret
  99         .cfi_endproc
 100 .LFE0:
 101         .size   foo, .-foo
 102         .globl  _start
 103         .type   _start, @function
 104 _start:
 105 .LFB1:
 106         .cfi_startproc
 107         pushq   %rbx
 108         .cfi_def_cfa_offset 16
 109         .cfi_offset 3, -16
 110         movl    %edi, %ebx
 111         movl    $1, %esi
 112         movl    $_start, %edi
 113         call    check_fptr
 114         movl    $1, %edi
 115         call    foo
 116         popq    %rbx
 117         .cfi_def_cfa_offset 8
 118   callq exit@PLT
 119         .cfi_endproc
 120 .LFE1:
 121         .size   _start, .-_start
 122         .globl  check_fptr
 123         .type   check_fptr, @function
 124 check_fptr:
 125 .LFB2:
 126         .cfi_startproc
 127         pushq   %rbp
 128         .cfi_def_cfa_offset 16
 129         .cfi_offset 6, -16
 130         movq    %rsp, %rbp
 131         .cfi_def_cfa_register 6
 132         movq    %rdi, -8(%rbp)
 133         movl    %esi, -12(%rbp)
 134         movl    -12(%rbp), %eax
 135         cltq
 136         movq    funcs(,%rax,8), %rax
 137         cmpq    %rax, -8(%rbp)
 138         je      .L33
 139         movl    $0, %eax
 140         movq    $0, (%rax)
 141 .L33:
 142         nop
 143         popq    %rbp
 144         .cfi_def_cfa 7, 8
 145         ret
 146         .cfi_endproc
 147
 148         .section        .rodata
 149         .align 8
 150         .align 4
 151 .L4:
 152         .quad   .L10
 153         .quad   .L8
 154         .quad   .L7
 155         .quad   .L6
 156         .quad   .L5
 157         .quad   .L3
 158
 159         .globl  funcs
 160         .type   funcs, @object
 161         .size   funcs, 16
 162 funcs:
 163         .quad   foo
 164         .quad   _start