align-branch-enhanced-relaxation.s
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# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s -x86-pad-max-prefix-size=1 --x86-align-branch-boundary=32 --x86-align-branch=jmp+indirect | llvm-objdump -d - | FileCheck %s
# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s --mc-relax-all | llvm-objdump -d - | FileCheck --check-prefixes=RELAX-ALL %s
# Exercise cases where we are allowed to increase the length of unrelaxable
# instructions (by adding prefixes) for alignment purposes.
# The first test checks instructions 'int3', 'push %rbp', which will be padded
# later are unrelaxable (their encoding size is still 1 byte when
# --mc-relax-all is passed).
.text
.globl labeled_unrelaxable_test
labeled_unrelaxable_test:
# RELAX-ALL: 0: cc int3
# RELAX-ALL: 1: 54 pushq %rsp
int3
push %rsp
# The second test is a basic test, we just check the jmp is aligned by prefix
# padding the previous instructions.
.text
.globl labeled_basic_test
labeled_basic_test:
.p2align 5
.rept 28
int3
.endr
# CHECK: 3c: 2e cc int3
# CHECK: 3e: 2e 54 pushq %rsp
# CHECK: 40: eb 00 jmp
int3
push %rsp
jmp foo
foo:
ret
# The third test check the correctness cornercase - can't add prefixes on a
# prefix or a instruction following by a prefix.
.globl labeled_prefix_test
labeled_prefix_test:
.p2align 5
.rept 28
int3
.endr
# CHECK: 7c: 2e cc int3
int3
# CHECK: 7e: 3e cc int3
DS
int3
# CHECK: 80: eb 00 jmp
jmp bar
bar:
ret