mirror of
https://github.com/llvm/llvm-project.git
synced 2025-04-17 03:36:37 +00:00
9d2dd009b6
Multi-way splitting can cause multiple fragments to access the same jump table. Relax the assumption that a jump table can only have up to two parents. Test Plan: added bolt/test/X86/three-way-split-jt.s Reviewers: ayermolo, dcci, rafaelauler, maksfb Reviewed By: rafaelauler, dcci Pull Request: https://github.com/llvm/llvm-project/pull/99988
96 lines
2.3 KiB
ArmAsm
96 lines
2.3 KiB
ArmAsm
## This reproduces an issue where the function is split into three fragments
|
|
## and all fragments access the same jump table.
|
|
|
|
# REQUIRES: system-linux
|
|
|
|
# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %s -o %t.o
|
|
# RUN: llvm-strip --strip-unneeded %t.o
|
|
# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q
|
|
# RUN: llvm-bolt %t.exe -o %t.out -v=1 -print-only=main.warm -print-cfg 2>&1 | FileCheck %s
|
|
|
|
# CHECK-DAG: BOLT-INFO: marking main.warm as a fragment of main
|
|
# CHECK-DAG: BOLT-INFO: marking main.cold as a fragment of main
|
|
# CHECK-DAG: BOLT-INFO: processing main.warm as a sibling of non-ignored function
|
|
# CHECK-DAG: BOLT-INFO: processing main.cold as a sibling of non-ignored function
|
|
# CHECK-DAG: BOLT-WARNING: Ignoring main.cold
|
|
# CHECK-DAG: BOLT-WARNING: Ignoring main.warm
|
|
# CHECK-DAG: BOLT-WARNING: Ignoring main
|
|
# CHECK: BOLT-WARNING: skipped 3 functions due to cold fragments
|
|
|
|
# CHECK: PIC Jump table JUMP_TABLE for function main, main.warm, main.cold
|
|
# CHECK-NEXT: 0x0000 : __ENTRY_main@0x[[#]]
|
|
# CHECK-NEXT: 0x0004 : __ENTRY_main@0x[[#]]
|
|
# CHECK-NEXT: 0x0008 : __ENTRY_main.cold@0x[[#]]
|
|
# CHECK-NEXT: 0x000c : __ENTRY_main@0x[[#]]
|
|
.globl main
|
|
.type main, %function
|
|
.p2align 2
|
|
main:
|
|
LBB0:
|
|
andl $0xf, %ecx
|
|
cmpb $0x4, %cl
|
|
## exit through ret
|
|
ja LBB3
|
|
|
|
## jump table dispatch, jumping to label indexed by val in %ecx
|
|
LBB1:
|
|
leaq JUMP_TABLE(%rip), %r8
|
|
movzbl %cl, %ecx
|
|
movslq (%r8,%rcx,4), %rax
|
|
addq %rax, %r8
|
|
jmpq *%r8
|
|
|
|
LBB2:
|
|
xorq %rax, %rax
|
|
LBB3:
|
|
addq $0x8, %rsp
|
|
ret
|
|
.size main, .-main
|
|
|
|
.globl main.warm
|
|
.type main.warm, %function
|
|
.p2align 2
|
|
main.warm:
|
|
LBB20:
|
|
andl $0xb, %ebx
|
|
cmpb $0x1, %cl
|
|
# exit through ret
|
|
ja LBB23
|
|
|
|
## jump table dispatch, jumping to label indexed by val in %ecx
|
|
LBB21:
|
|
leaq JUMP_TABLE(%rip), %r8
|
|
movzbl %cl, %ecx
|
|
movslq (%r8,%rcx,4), %rax
|
|
addq %rax, %r8
|
|
jmpq *%r8
|
|
|
|
LBB22:
|
|
xorq %rax, %rax
|
|
LBB23:
|
|
addq $0x8, %rsp
|
|
ret
|
|
.size main.warm, .-main.warm
|
|
|
|
## cold fragment is only reachable through jump table
|
|
.globl main.cold
|
|
.type main.cold, %function
|
|
main.cold:
|
|
leaq JUMP_TABLE(%rip), %r8
|
|
movzbl %cl, %ecx
|
|
movslq (%r8,%rcx,4), %rax
|
|
addq %rax, %r8
|
|
jmpq *%r8
|
|
LBB4:
|
|
callq abort
|
|
.size main.cold, .-main.cold
|
|
|
|
.rodata
|
|
## jmp table, entries must be R_X86_64_PC32 relocs
|
|
.globl JUMP_TABLE
|
|
JUMP_TABLE:
|
|
.long LBB2-JUMP_TABLE
|
|
.long LBB3-JUMP_TABLE
|
|
.long LBB4-JUMP_TABLE
|
|
.long LBB3-JUMP_TABLE
|