GCC info: gcc -v
Reading specs from
/home/cvogler/addons/gcc-test/lib/gcc/x86_64-unknown-linux-gnu/3.4.3/specs
Configured with: ../gcc-3.4.3/configure --prefix=/home/cvogler/addons/gcc-test
--disable-multilib
Thread model: posix
gcc version 3.4.3
The following test snippet shows a very reduced case of Cholesky factorization
code, which uses inline functions for array indexing. It is miscompiled with
these compiler flags on the x86_64 target:
gcc -Wall -O -finline-functions -o test test.c -lm
--- test.c ---
#include <math.h>
double getval()
{
return -1.0;
}
int main(void)
{
double y = sqrt(getval());
}
---
The result is in infinite loop, instead of the expected "nan." This generated
assembler snippet, in particular, looks incorrect:
---
.L3:
sqrtsd %xmm0, %xmm0
ucomisd %xmm0, %xmm0
jp .L6
je .L4
.L6:
movlpd .LC3(%rip), %xmm0
jmp .L3
.L4:
rep ; ret
---
In this snippet .L6 should contain a call to the sqrt function, but instead it
jumps back to .L3, causing an infinite loop. Suppressing inlining of functions
makes gcc generate correct code. Also, I could not reproduce the problem on a
32-bit x86 target.
--
Summary: [x86-64] gcc miscompiles composition of sqrt() with
inlined function
Product: gcc
Version: 3.4.3
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: cvogler2001 at yahoo dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: x86_64-unknown-linux-gnu
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20688
