https://llvm.org/bugs/show_bug.cgi?id=26009
Bug ID: 26009
Summary: wrong code (that hangs) at -Os and above on
x86_64-linux-gnu in 32-bit mode
Product: clang
Version: trunk
Hardware: PC
OS: All
Status: NEW
Severity: normal
Priority: P
Component: -New Bugs
Assignee: unassignedclangb...@nondot.org
Reporter: s...@cs.ucdavis.edu
CC: llvm-bugs@lists.llvm.org
Classification: Unclassified
The following code is miscompiled by the current clang trunk on
x86_64-linux-gnu at -Os and above in 32-bit mode (but not in 64-bit mode).
This is a regression from 3.7.x.
$ clang-trunk -v
clang version 3.8.0 (trunk 256693)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/tools/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9.3
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.2.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.2.1
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$
$ clang-trunk -m32 -O1 small.c; ./a.out
$ clang-trunk -m64 -Os small.c; ./a.out
$ clang-3.7.0 -m32 -Os small.c; ./a.out
$
$ clang-trunk -m32 -Os small.c
$ timeout -s 9 10 ./a.out
Killed
$ clang-trunk -m32 -O2 small.c
$ timeout -s 9 10 ./a.out
Killed
$ clang-trunk -m32 -O3 small.c
$ timeout -s 9 10 ./a.out
Killed
$
-----------------------------------------
unsigned char a, d, g;
static unsigned char *b = &a, *e = &d;
short c;
int f;
void
fn1 (int p1)
{
short *h = &c;
++*h;
*e = --*b >> 6 | (g != 0);
if (a < 240 && c)
for (;;)
;
}
int
main ()
{
fn1 (f);
return 0;
}
--
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
