arm-thumb2-ldrlit.s 4.85 KB
// REQUIRES: arm
// RUN: llvm-mc --triple=thumbv7m-none-eabi --arm-add-build-attributes -filetype=obj -o %t.o %s
// RUN: echo "SECTIONS { \
// RUN:                 .rodata.low 0x8012  : { *(.rodata.low) } \
// RUN:                 .text.low   0x8f00  : { *(.text.low) } \
// RUN:                 .text.neg   0x9000  : { *(.text.neg) } \
// RUN:                 .text.pos   0x10000 : { *(.text.pos) } \
// RUN:                 .text.high  0x10100 : { *(.text.high) } \
// RUN:                 .data_high  0x1100f : { *(.data.high) } \
// RUN:               } " > %t.script
// RUN: ld.lld --script %t.script %t.o -o %t
// RUN: llvm-readobj --symbols %t | FileCheck %s --check-prefix=SYMS
// RUN: llvm-objdump -d --no-show-raw-insn --triple=thumbv7m-none-eabi %t | FileCheck %s

/// Test the various legal cases for the R_ARM_THM_PC12 relocation
/// Interesting things to note
/// Range is +- 4095 bytes
/// The Thumb bit for function symbols is ignored
/// The expression is S + A - Pa where Pa is AlignDown(PC, 4) so we will use
/// 2-byte nops to make some of the ldr instructions 2-byte aligned.
 .section .rodata.low, "a", %progbits
dat1:
 .byte 0
dat2:
 .byte 1
dat3:
 .byte 2
dat4:
 .byte 3

 .section .text.low, "ax", %progbits
 .balign 4
 .global target1
 .type target1, %function
target1:
 bx lr
 .type target2, %function
target2:
 bx lr

 .section .text.neg, "ax", %progbits
 .balign 4
 .global _start
 .thumb_func
_start:
 nop
/// ldr r0, dat1
 .inst.w 0xf85f0004
 .reloc 2, R_ARM_THM_PC12, dat1
/// ldr r1, dat2
 .inst.w 0xf85f1004
 .reloc 6, R_ARM_THM_PC12, dat2
 nop
/// ldr r2, dat3
 .inst.w 0xf85f2004
 .reloc 0xc, R_ARM_THM_PC12, dat3
/// ldr r3, dat4
 .inst.w 0xf85f3004
 .reloc 0x10, R_ARM_THM_PC12, dat4

/// ldr r0, target1
 .inst.w 0xf85f0004
 .reloc 0x14, R_ARM_THM_PC12, target1

 nop
/// ldr r1, target2
 .inst.w 0xf85f1004
 .reloc 0x1a, R_ARM_THM_PC12, target2

 .section .text.pos, "ax", %progbits
 .balign 4
 .global pos
 .thumb_func
pos:
/// ldr r2, target3
 .inst.w 0xf85f2004
 .reloc 0, R_ARM_THM_PC12, target3
 nop
/// ldr r3, target4
 .inst.w 0xf85f3004
 .reloc 6, R_ARM_THM_PC12, target4
 nop
/// ldr r0, dat5
 .inst.w 0xf85f0004
 .reloc 0xc, R_ARM_THM_PC12, dat5
/// ldr r1, dat6
 .inst.w 0xf85f1004
 .reloc 0x10, R_ARM_THM_PC12, dat6
 nop
/// ldr r2, dat7
 .inst.w 0xf85f2004
 .reloc 0x16, R_ARM_THM_PC12, dat7
/// ldr r3, dat8
 .inst.w 0xf85f3004
 .reloc 0x1a, R_ARM_THM_PC12, dat8
/// positive addend in instruction, all others are -4 (PC bias)
///ldr.w r4, dat5 + 8
 .inst 0xf8df4004
 .reloc 0x1e, R_ARM_THM_PC12, dat5

 .section .text.high, "ax", %progbits
 .balign 4
 .thumb_func
 .global target3
target3:
 bx lr
 .thumb_func
target4:
 bx lr

 .section .data.high, "aw", %progbits
dat5:
 .byte 0
dat6:
 .byte 1
dat7:
 .byte 2
dat8:
 .byte 3

// SYMS:     Name: dat1
// SYMS-NEXT:     Value: 0x8012
// SYMS:     Name: dat2
// SYMS-NEXT:     Value: 0x8013
// SYMS:     Name: dat3
// SYMS-NEXT:     Value: 0x8014
// SYMS:     Name: dat4
// SYMS-NEXT:     Value: 0x8015

// CHECK: 00008f00 <target1>:
// CHECK-NEXT:     8f00: bx      lr
// CHECK: 00008f02 <target2>:
// CHECK-NEXT:     8f02: bx      lr

// CHECK: 00009000 <_start>:
// CHECK-NEXT:     9000: nop
/// AlignDown(0x9002+4, 4) - 0xff2 = 0x8012
// CHECK-NEXT:     9002: ldr.w   r0, [pc, #-4082]
/// AlignDown(0x9006+4, 4) - 0xff5 = 0x8013
// CHECK-NEXT:     9006: ldr.w   r1, [pc, #-4085]
// CHECK-NEXT:     900a: nop
/// AlignDown(0x900c+4, 4) - 0xffc = 0x8014
// CHECK-NEXT:     900c: ldr.w   r2, [pc, #-4092]
/// AlignDown(0x9010+4, 4) - 0xfff = 0x8015
// CHECK-NEXT:     9010: ldr.w   r3, [pc, #-4095]
/// AlignDown(0x9014+4, 4) - 0x118 = 0x8f00
// CHECK-NEXT:     9014: ldr.w   r0, [pc, #-280]
// CHECK-NEXT:     9018: nop
/// AlignDown(0x901a+4, 4) - 0x11a = 0x8f02
// CHECK-NEXT:     901a: ldr.w   r1, [pc, #-282]

// CHECK: 00010000 <pos>:
/// AlignDown(0x10000+4, 4) + 0x1c = 0x10100
// CHECK-NEXT:    10000: ldr.w   r2, [pc, #252]
// CHECK-NEXT:    10004: nop
/// AlignDown(0x10006+4, 4) + 0x1a = 0x10122
// CHECK-NEXT:    10006: ldr.w   r3, [pc, #250]
// CHECK-NEXT:    1000a: nop
/// AlignDown(0x1000c+4, 4) + 0xfff = 0x1100f
// CHECK-NEXT:    1000c: ldr.w   r0, [pc, #4095]
/// AlignDown(0x10010+4, 4) + 0xffc = 0x11010
// CHECK-NEXT:    10010: ldr.w   r1, [pc, #4092]
// CHECK-NEXT:    10014: nop
/// AlignDown(0x10016+4, 4) + 0xff9 = 0x11011
// CHECK-NEXT:    10016: ldr.w   r2, [pc, #4089]
/// AlignDown(0x1001a+4, 4) + 0xff6 = 0x11012
// CHECK-NEXT:    1001a: ldr.w   r3, [pc, #4086]
/// AlignDown(0x1001e+4, 4) + 0xff7 = 0x11017 = dat5 + 8
// CHECK-NEXT:    1001e: ldr.w   r4, [pc, #4087]

// CHECK: 00010100 <target3>:
// CHECK-NEXT:    10100: bx      lr

// CHECK: 00010102 <target4>:
// CHECK-NEXT:    10102: bx      lr

// SYMS:     Name: dat5
// SYMS-NEXT:     Value: 0x1100F
// SYMS:     Name: dat6
// SYMS-NEXT:     Value: 0x11010
// SYMS:     Name: dat7
// SYMS-NEXT:     Value: 0x11011
// SYMS:     Name: dat8
// SYMS-NEXT:     Value: 0x11012