https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104189
Bug ID: 104189
Summary: [sparc] Inconsistent behavior for -mcpu=v9 -m32 on
Linux and Solaris
Product: gcc
Version: 11.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: glaubitz at physik dot fu-berlin.de
CC: ebotcazou at gcc dot gnu.org, jrtc27 at jrtc27 dot com,
matorola at gmail dot com
Target Milestone: ---
Target: sparc-*-*-*
On Solaris and Linux, 32-bit V9 behave differently in regards to what size of
atomic operations are supported.
On Linux, the maximum size for an atomic operation on 32-bit V9 is 32 bits, on
Solaris it is 64 bits. Moreover, setting -mcpu=ultrasparc3 makes the two match
again.
Linux:
glaubitz@gcc202:~$ echo | gcc -m32 -mcpu=v9 -E -dM -|grep -i SWAP
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
glaubitz@gcc202:~$ echo | gcc -m32 -mcpu=ultrasparc3 -E -dM -|grep -i SWAP
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
glaubitz@gcc202:~$
Solaris:
sysadmin@deimos:~$ echo | gcc -m32 -mcpu=v9 -E -dM -|grep -i SWAP
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
sysadmin@deimos:~$ echo | gcc -m32 -mcpu=ultrasparc3 -E -dM -|grep -i SWAP
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1
sysadmin@deimos:~$
Unless there is a specific reason, it would nice if the behavior was consistent
for both Linux and Solaris such that code that wants to use 64-bit atomics
would behave the same on the two platforms.
