https://bugs.llvm.org/show_bug.cgi?id=49171
Bug ID: 49171
Summary: Instcombine infinite combine loop with -O3
Product: libraries
Version: trunk
Hardware: PC
OS: Linux
Status: NEW
Severity: enhancement
Priority: P
Component: Scalar Optimizations
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected]
Hi, all.
This code, s.c, is a valid program but makes Clang hung on with -O3 at compile
time.
$cat s.c
int a, b, c, d;
void e() {
a = 7;
for (; a <= 78; a++) {
d = 3;
for (; d <= 73; d++) {
int f = 0;
b += c;
if (b) {
int g = 0;
for (f = 5; f; g)
;
}
}
}
}
$clang -c -w -O3 s.c
//endless compiling
This problem only occurs in clang-trunk with -O3, and other released versions
or optimization flags seem well while dealing with this case.
$clang -v
clang version 13.0.0 (https://github.com/llvm/llvm-project
48bdd676a1d1338c10541460bf5beb69ac17e451)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir:
/home/haoxin/haoxin-data/dut-research/compilers/llvm-project/build-20210127/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Candidate multilib: .;@m64
Selected multilib: .;@m64
Thanks.
Haoxin
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
