llvm-project/bolt/test/X86/shrinkwrapping-and-rsp.s

56 lines
1.7 KiB
ArmAsm

# This checks that shrink wrapping does attempt at accessing stack elements
# using RSP when the function is aligning RSP and changing offsets.
# REQUIRES: system-linux
# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown \
# RUN: %s -o %t.o
# RUN: link_fdata %s %t.o %t.fdata
# RUN: llvm-strip --strip-unneeded %t.o
# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q -nostdlib
# RUN: llvm-bolt %t.exe -o %t.out --data %t.fdata \
# RUN: --frame-opt=all --simplify-conditional-tail-calls=false \
# RUN: --eliminate-unreachable=false | FileCheck %s
# Here we have a function that aligns the stack at prologue. Stack pointer
# analysis can't try to infer offset positions after AND because that depends
# on the runtime value of the stack pointer of callee (whether it is misaligned
# or not).
.globl _start
.type _start, %function
_start:
.cfi_startproc
# FDATA: 0 [unknown] 0 1 _start 0 0 1
push %rbp
mov %rsp, %rbp
push %rbx
push %r14
and $0xffffffffffffffe0,%rsp
subq $0x20, %rsp
b: je hot_path
# FDATA: 1 _start #b# 1 _start #hot_path# 0 1
cold_path:
mov %r14, %rdi
mov %rbx, %rdi
# Block push-pop mode by using an instruction that requires the
# stack to be aligned to 128B. This will force the pass
# to try to index stack elements by using RSP +offset directly, but
# we do not know how to access individual elements of the stack thanks
# to the alignment.
movdqa %xmm8, (%rsp)
addq $0x20, %rsp
pop %r14
pop %rbx
pop %rbp
ret
hot_path:
addq $0x20, %rsp
pop %r14
pop %rbx
pop %rbp
ret
.cfi_endproc
.size _start, .-_start
# CHECK: BOLT-INFO: Shrink wrapping moved 0 spills inserting load/stores and 0 spills inserting push/pops