https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105950
Bug ID: 105950
Summary: > O2 optimization causes runtime (SIGILL) during main
initialization
Product: gcc
Version: 9.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: jkanapes at yahoo dot com
Target Milestone: ---
Created attachment 53128
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53128&action=edit
gcc -v -save -temps
Recently upgraded to Ubuntu 20.04, and a program that compiled & ran fine in
Ubuntu 14.04, now coredumps in execution when optimization greater than -O2 is
used during compilation. No warnings in compilation.
When compiled with -O3 -g flags I get gdb output to the offending code
(SIGILL):
size_t channel = 0;
uhd_stream_args_t stream_args =
{
.cpu_format = "fc32",
.otw_format = "sc16",
.args = "",
.channel_list = &channel,
.n_channels = 1
};
uhd_stream_atgs_t is defined in the included header:
typedef struct {
//! Format of host memory
char* cpu_format;
//! Over-the-wire format
char* otw_format;
//! Other stream args
char* args;
//! Array that lists channels
size_t* channel_list;
//! Number of channels
int n_channels;
} uhd_stream_args_t;
The offending code is the next block. This initialization code used to work
fine. It bow works fine with -O2 or less optimization. It compiles fine. Why
does gcc create the wrong executable?
Attaching the gcc -v -save-temps output
