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# This checks that we don't create an invalid CFG when there is an
# unreachable direct jump right after an indirect one.
# 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 -no-pie %t.o -o %t.exe -Wl,-q -nostdlib
# RUN: llvm-bolt %t.exe -o %t.out --data %t.fdata \
# RUN: --eliminate-unreachable --print-cfg | FileCheck %s
.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
subq $0x20, %rsp
movq %rdi, %rcx
b:
jmpq *JUMP_TABLE(,%rcx,8)
# FDATA: 1 _start #b# 1 _start #hotpath# 0 20
# Unreachable direct jump here. Our CFG should still make sense and properly
# place this instruction in a new basic block.
jmp .lbb2
.lbb1: je .lexit
.lbb2:
xorq %rax, %rax
addq $0x20, %rsp
pop %r14
pop %rbx
pop %rbp
ret
hotpath:
movq $2, %rax
addq $0x20, %rsp
pop %r14
pop %rbx
pop %rbp
ret
.lexit:
movq $1, %rax
addq $0x20, %rsp
pop %r14
pop %rbx
pop %rbp
ret
.cfi_endproc
.size _start, .-_start
.rodata
.globl JUMP_TABLE
JUMP_TABLE:
.quad .lbb1
.quad .lbb2
.quad hotpath
# No basic blocks above should have 4 successors! That is a bug.
# CHECK-NOT: Successors: {{.*}} (mispreds: 0, count: 20), {{.*}} (mispreds: 0, count: 0), {{.*}} (mispreds: 0, count: 0), {{.*}} (mispreds: 0, count: 0)
# Check successful removal of stray direct jmp
# CHECK: UCE removed 1 block
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