mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-19 18:46:30 +00:00
65 lines
1.3 KiB
ArmAsm
65 lines
1.3 KiB
ArmAsm
# thumb_blx_in_range.s
|
|
#
|
|
# Test THUMB/THUMB-2 blx instructions just within the branch range limits.
|
|
# Because bit 1 of the branch target comes from the branch instruction
|
|
# address, the branch range from PC (branch instruction address + 4) is
|
|
# acutally -((1<<22) + 2) to ((1<<22) - 4) for THUMB and -((1<<24) + 2) to
|
|
# ((1<<24) - 4) from THUMB2.
|
|
|
|
.syntax unified
|
|
.section .text.pre,"x"
|
|
|
|
# Add padding so that target is just in branch range.
|
|
.space 8
|
|
|
|
.align 2
|
|
.global _backward_target
|
|
.code 32
|
|
.type _backword_target, %function
|
|
_backward_target:
|
|
bx lr
|
|
.size _backward_target, .-_backward_target
|
|
|
|
.text
|
|
|
|
# Define _start so that linker does not complain.
|
|
.global _start
|
|
.code 32
|
|
.align 2
|
|
.type _start, %function
|
|
_start:
|
|
bx lr
|
|
.size _start, .-_start
|
|
|
|
.global _backward_test
|
|
.code 16
|
|
.thumb_func
|
|
.type _backward_test, %function
|
|
_backward_test:
|
|
nop.n
|
|
blx _backward_target
|
|
.size _backward_test, .-_backward_test
|
|
|
|
.align 2
|
|
.global _forward_test
|
|
.code 16
|
|
.thumb_func
|
|
.type _forward_test, %function
|
|
_forward_test:
|
|
blx _forward_target
|
|
.size _forward_test, .-_forward_test
|
|
.code 32
|
|
|
|
.section .text.post,"x"
|
|
|
|
# Add padding so that target is just in branch range.
|
|
.space 12
|
|
|
|
.align 2
|
|
.global _forward_target
|
|
.code 32
|
|
.type _forward_target, %function
|
|
_forward_target:
|
|
bx lr
|
|
.size _forward_target, .-_forward_target
|