bolt/test/AArch64/test-indirect-branch.s

   1 // Test how BOLT handles indirect branch sequence of instructions in
   2 // AArch64MCPlus builder.
   3
   4 // clang-format off
   5
   6 // REQUIRES: system-linux
   7 // RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o
   8 // RUN: %clang %cflags --target=aarch64-unknown-linux %t.o -o %t.exe -Wl,-q
   9 // RUN: llvm-bolt %t.exe -o %t.bolt --print-cfg --strict\
  10 // RUN:  -v=1 2>&1 | FileCheck %s
  11
  12 // Pattern 1: there is no shift amount after the 'add' instruction.
  13 //
  14 //   adr     x6, 0x219fb0 <sigall_set+0x88>
  15 //   add     x6, x6, x14, lsl #2
  16 //   ldr     w7, [x6]
  17 //   add     x6, x6, w7, sxtw => no shift amount
  18 //   br      x6
  19 //
  20
  21 // Pattern 2: nop/adr pair is used in place of adrp/add
  22 //
  23 //  nop   => nop/adr instead of adrp/add
  24 //  adr     x13, 0x215a18 <_nl_value_type_LC_COLLATE+0x50>
  25 //  ldrh    w13, [x13, w12, uxtw #1]
  26 //  adr     x12, 0x247b30 <__gettextparse+0x5b0>
  27 //  add     x13, x12, w13, sxth #2
  28 //  br      x13
  29
  30   .section .text
  31   .align 4
  32   .globl _start
  33   .type  _start, %function
  34 _start:
  35   bl      test1
  36   bl      test2
  37 // mov x0, #4
  38 // mov w8, #93
  39 // svc #0
  40
  41 // Pattern 1
  42 // CHECK: BOLT-WARNING: Failed to match indirect branch: ShiftVAL != 2
  43   .globl test1
  44   .type  test1, %function
  45 test1:
  46   mov     x1, #0
  47   adr     x3, datatable
  48   add     x3, x3, x1, lsl #2
  49   ldr     w2, [x3]
  50   add     x3, x3, w2, sxtw
  51   br      x3
  52 test1_0:
  53    ret
  54 test1_1:
  55    ret
  56 test1_2:
  57    ret
  58
  59 // Pattern 2
  60 // CHECK: BOLT-WARNING: Failed to match indirect branch: nop/adr instead of adrp/add
  61   .globl test2
  62   .type  test2, %function
  63 test2:
  64   nop
  65   adr     x3, jump_table
  66   ldrh    w3, [x3, x1, lsl #1]
  67   adr     x1, test2_0
  68   add     x3, x1, w3, sxth #2
  69   br      x3
  70 test2_0:
  71   ret
  72 test2_1:
  73   ret
  74
  75   .section .rodata,"a",@progbits
  76 datatable:
  77   .word test1_0-datatable
  78   .word test1_1-datatable
  79   .word test1_2-datatable
  80
  81 jump_table:
  82   .hword  (test2_0-test2_0)>>2
  83   .hword  (test2_1-test2_0)>>2