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# This reproduces a bug with shrink wrapping when trying to move
# push-pops in a function where we are not allowed to modify the
# stack layout for alignment reasons. In this bug, we failed to
# propagate alignment requirement upwards in the call graph for
# some functions when there is a cycle in the call graph.
# 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
# Delete our BB symbols so BOLT doesn't mark them as entry points
# RUN: llvm-strip --strip-unneeded %t.o
# RUN: %clang %cflags -no-pie %t.o -o %t.exe -Wl,-q
# RUN: llvm-bolt %t.exe --relocs=1 --frame-opt=all --print-finalized \
# RUN: --lite=0 --print-only=main --data %t.fdata -o %t.out | FileCheck %s
# RUN: %t.out
# CHECK: BOLT-INFO: Shrink wrapping moved 1 spills inserting load/stores and 0 spills inserting push/pops
.text
.globl bar
.type bar, %function
.p2align 4
bar:
# FDATA: 0 [unknown] 0 1 bar 0 0 510
pushq %rbp
movq %rsp, %rbp
pushq %rbx # We save rbx here, but there is an
# opportunity to move it to .BB2
subq $0x18, %rsp
cmpl $0x2, %edi
.J1:
jb .BBend
# FDATA: 1 bar #.J1# 1 bar #.BB2# 0 10
# FDATA: 1 bar #.J1# 1 bar #.BBend# 0 500
.BB2:
movq $2, %rbx # Use rbx in a cold block
xorq %rax, %rax
movb mystring, %al
addq %rbx, %rax
movb %al, mystring
leaq mystring, %rdi
#callq puts
.BBend:
addq $0x18, %rsp
pop %rbx # Restore
xorq %rax, %rax
cmpq $0x0, %rax
jne .BBnever
jmp .BBbarend
.BBnever:
# This is a path that is never executed, but we add a call to main here
# to force a cycle in the call graph and to require us to have an aligned
# stack
callq main
.BBbarend:
leaveq
retq
.size bar, .-bar
# Frame alignedness information needs to be transmitted from foo to main to bar
.globl main
.type main, %function
.p2align 4
main:
# Call a function that requires an aligned stack
callq foo
# Call a function that can be shrink-wrapped
callq bar
retq
.size main, .-main
# Frame alignedness information needs to be transmitted from foo to main to bar
.globl foo
.type foo, %function
.p2align 4
foo:
# Use an instruction that requires an aligned stack
movdqa -0x10(%rsp), %xmm0
retq
.size foo, .-foo
.data
mystring: .asciz "0 is rbx mod 10 contents in decimal\n"
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