segmentation fault of target program caused by loop-reroll with "opt -mem2reg -loop-unswitch -indvars -loop-rotate -loop-unswitch -jump-threading -loop-unroll -jump-threading -loop-reroll" #41612
Description
| Bugzilla Link | 42267 |
| Version | trunk |
| OS | Linux |
| Attachments | .bc file of the source code, small-opt.bc |
| CC | @efriedma-quic,@fhahn |
Extended Description
$clang -v
clang version 9.0.0 (trunk 362492)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/jack-zhou/Documents/llvm/llvm_truck/llvm2/build/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$gcc small.c -o small1.out && ./small1.out
0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
$clang small.c -o small2.out && ./small2.out
0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
$clang -O3 -c -emit-llvm -mllvm -disable-llvm-optzns small.c
$opt -mem2reg -loop-unswitch -indvars -loop-rotate -loop-unswitch -jump-threading -loop-unroll -jump-threading small.bc -o small-opt.bc
$clang small-opt.bc -o small3.out && ./small3.out
Segmentation fault (core dumped)without loop-reroll pass, the output is correct.
$$opt -mem2reg -loop-unswitch -indvars -loop-rotate -loop-unswitch -jump-threading -loop-unroll -jump-threading small.bc -o small-opt1.bc
$clang small-opt1.bc -o small4.out && ./small4.out
0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000#include<stdio.h>
int a[8][10][2];
void main() {
int b, c, d;
for (b = 0; b < 8; b++)
for (c = 0; c < 10; c++)
for (d = 0; d < 2; d++)
printf("%d", a[b][c][d]);
}