lld/test/ELF/arm-thumb-blx.s

   1 // REQUIRES: arm
   2 // RUN: llvm-mc -filetype=obj -triple=thumbv7a-none-linux-gnueabi %s -o %t
   3 // RUN: llvm-mc -filetype=obj -triple=thumbv7a-none-linux-gnueabi %S/Inputs/arm-thumb-blx-targets.s -o %ttarget
   4 // RUN: echo "SECTIONS { \
   5 // RUN:          .R_ARM_CALL24_callee1 : { *(.R_ARM_CALL24_callee_low) } \
   6 // RUN:          .R_ARM_CALL24_callee2 : { *(.R_ARM_CALL24_callee_thumb_low) } \
   7 // RUN:          .caller : { *(.text) } \
   8 // RUN:          .R_ARM_CALL24_callee3 : { *(.R_ARM_CALL24_callee_high) } \
   9 // RUN:          .R_ARM_CALL24_callee4 : { *(.R_ARM_CALL24_callee_thumb_high) } } " > %t.script
  10 // RUN: ld.lld --script %t.script %t %ttarget -o %t2
  11 // RUN: llvm-objdump -d %t2 | FileCheck %s
  12 // Test BLX instruction is chosen for Thumb BL/BLX instruction and ARM callee
  13 // 2 byte nops are used to test the pc-rounding behaviour. As a BLX from a
  14 // 2 byte aligned destination is defined as Align(PC,4) + immediate:00
  15 // FIXME: llvm-mc has problems assembling BLX unless the destination is
  16 // external. The targets of the BL and BLX instructions are in arm-thumb-blx-target.s
  17  .syntax unified
  18  .section .text, "ax",%progbits
  19  .thumb
  20  .globl _start
  21  .balign 0x10000
  22  .type _start,%function
  23 _start:
  24  blx  callee_low
  25  nop
  26  bl callee_low
  27  nop
  28  blx  callee_high
  29  nop
  30  bl callee_high
  31  nop
  32  blx  blx_far
  33  nop
  34  bl   blx_far
  35  nop
  36 // Expect BLX to thumb target to be written out as a BL
  37  blx   callee_thumb_low
  38  nop
  39  blx   callee_thumb_high
  40  bx lr
  41
  42 // CHECK: Disassembly of section .R_ARM_CALL24_callee1:
  43 // CHECK-EMPTY:
  44 // CHECK-NEXT-ARM: callee_low:
  45 // CHECK-NEXT-ARM:      b4:     1e ff 2f e1     bx      lr
  46
  47 // CHECK: Disassembly of section .R_ARM_CALL24_callee2:
  48 // CHECK-EMPTY:
  49 // CHECK-NEXT-THUMB: callee_thumb_low:
  50 // CHECK-NEXT-THUMB:     100:   70 47   bx      lr
  51
  52 // CHECK: Disassembly of section .caller:
  53 // CHECK-EMPTY:
  54 // CHECK: <_start>:
  55 // Align(0x10000,4) - 0xff50 (65360) + 4 = 0xb4 = callee_low
  56 // CHECK-NEXT-THUMB:   10000:       f0 f7 58 e8     blx     #-65360
  57 // CHECK-NEXT-THUMB:   10004:       00 bf   nop
  58 // Align(0x10006,4) - 0xff54 (65364) + 4 = 0xb4 = callee_low
  59 // CHECK-NEXT-THUMB:   10006:       f0 f7 56 e8     blx     #-65364
  60 // CHECK-NEXT-THUMB:   1000a:       00 bf   nop
  61 // Align(0x1000c,4) + 0xf0 (240) + 4 = 0x10100 = callee_high
  62 // CHECK-NEXT-THUMB:   1000c:   00 f0 78 e8     blx     #240
  63 // CHECK-NEXT-THUMB:   10010:       00 bf   nop
  64 // Align(0x10012,4) + 0xec (236) + 4 = 0x10100 = callee_high
  65 // CHECK-NEXT-THUMB:   10012:       00 f0 76 e8     blx     #236
  66 // CHECK-NEXT-THUMB:   10016:       00 bf   nop
  67 // Align(0x10018,4) + 0xfffffc (16777212) = 0x1010018 = blx_far
  68 // CHECK-NEXT-THUMB:   10018:       ff f3 fe c7     blx     #16777212
  69 // CHECK-NEXT-THUMB:   1001c:       00 bf   nop
  70 // Align(0x1001e,4) + 0xfffff8 (16777208) = 0x1010018 = blx_far
  71 // CHECK-NEXT-THUMB:   1001e:       ff f3 fc c7     blx     #16777208
  72 // CHECK-NEXT-THUMB:   10022:       00 bf   nop
  73 // 10024 - 0xff28 (65320) + 4 = 0x100 = callee_thumb_low
  74 // CHECK-NEXT-THUMB:   10024:       f0 f7 6c f8     bl      #-65320
  75 // CHECK-NEXT-THUMB:   10028:       00 bf   nop
  76 // 1002a + 0x1d2 (466) + 4 = 0x10200 = callee_thumb_high
  77 // CHECK-NEXT-THUMB:   1002a:       00 f0 e9 f8     bl      #466
  78 // CHECK-NEXT-THUMB:   1002e:       70 47   bx      lr
  79
  80
  81 // CHECK: Disassembly of section .R_ARM_CALL24_callee3:
  82 // CHECK-EMPTY:
  83 // CHECK-NEXT-ARM: callee_high:
  84 // CHECK-NEXT-ARM:   10100:     1e ff 2f e1     bx      lr
  85
  86 // CHECK: Disassembly of section .R_ARM_CALL24_callee4:
  87 // CHECK-EMPTY:
  88 // CHECK-NEXT-THUMB:callee_thumb_high:
  89 // CHECK-NEXT-THUMB:   10200:   70 47   bx      lr