1## This reproduces an issue where two fragments of same function access same 2## jump table, which means at least one fragment visits the other, i.e., one 3## of them has split jump table. As a result, all of them will be marked as 4## non-simple function. 5 6# REQUIRES: system-linux 7 8# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %s -o %t.o 9# RUN: llvm-strip --strip-unneeded %t.o 10# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q 11# RUN: llvm-bolt -print-cfg -v=3 %t.exe -o %t.out 2>&1 | FileCheck %s 12 13# CHECK: BOLT-INFO: Multiple fragments access same jump table: main; main.cold.1 14# CHECK: PIC Jump table JUMP_TABLE1 for function main, main.cold.1 at {{.*}} with a total count of 0: 15 16 .text 17 .globl main 18 .type main, %function 19 .p2align 2 20main: 21LBB0: 22 andl $0xf, %ecx 23 cmpb $0x4, %cl 24 ## exit through ret 25 ja LBB3 26 27## jump table dispatch, jumping to label indexed by val in %ecx 28LBB1: 29 leaq JUMP_TABLE1(%rip), %r8 30 movzbl %cl, %ecx 31 movslq (%r8,%rcx,4), %rax 32 addq %rax, %r8 33 jmpq *%r8 34 35LBB2: 36 xorq %rax, %rax 37LBB3: 38 addq $0x8, %rsp 39 ret 40.size main, .-main 41 42## cold fragment is only reachable 43 .globl main.cold.1 44 .type main.cold.1, %function 45 .p2align 2 46main.cold.1: 47 ## load bearing nop: pad LBB8 so that it can't be treated 48 ## as __builtin_unreachable by analyzeJumpTable 49 nop 50LBB4: 51 andl $0xb, %ebx 52 cmpb $0x1, %cl 53 # exit through ret 54 ja LBB7 55 56## jump table dispatch, jumping to label indexed by val in %ecx 57LBB5: 58 leaq JUMP_TABLE1(%rip), %r8 59 movzbl %cl, %ecx 60 movslq (%r8,%rcx,4), %rax 61 addq %rax, %r8 62 jmpq *%r8 63 64LBB6: 65 xorq %rax, %rax 66LBB7: 67 addq $0x8, %rsp 68 ret 69LBB8: 70 callq abort 71.size main.cold.1, .-main.cold.1 72 73 .rodata 74## jmp table, entries must be R_X86_64_PC32 relocs 75 .globl JUMP_TABLE1 76JUMP_TABLE1: 77 .long LBB2-JUMP_TABLE1 78 .long LBB3-JUMP_TABLE1 79 .long LBB8-JUMP_TABLE1 80 .long LBB6-JUMP_TABLE1 81 .long LBB7-JUMP_TABLE1 82