Re: port-sparc/58352: ld: /usr/lib/libubsan.so: undefined reference to `__sync_val_compare_and_swap_8'

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

The following reply was made to PR port-sparc/58352; it has been noted by GNATS.

From: Rin Okuyama <rokuyama.rk%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost, Taylor R Campbell <riastradh%NetBSD.org@localhost>,
 matthew green <mrg%NetBSD.org@localhost>
Cc: port-sparc-maintainer%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
 netbsd-bugs%netbsd.org@localhost
Subject: Re: port-sparc/58352: ld: /usr/lib/libubsan.so: undefined reference
 to `__sync_val_compare_and_swap_8'
Date: Wed, 19 Jun 2024 23:44:09 +0900

 On 2024/06/19 1:52, matthew green wrote:
 > campbell+netbsd%mumble.net@localhost writes:
 >>> Number:         58352
 >>> Category:       port-sparc
 >>> Synopsis:       ld: /usr/lib/libubsan.so: undefined reference to `__sync_val_compare_and_swap_8'
 > 
 > hmm, i thought i'd avoided this already.
 > 
 > it's one of the notes in README.gcc12.
 
 It seems that `-mcpu=v8` is not sufficient for sparc:
 
 (1) 64-bit atomic ops requires V8PLUS:
 
 https://github.com/NetBSD/src/blob/trunk/external/gpl3/gcc/dist/gcc/config/sparc/sync.md#L23
 
 (2) V8PLUS requires both VIS and V9:
 
 https://github.com/NetBSD/src/blob/trunk/external/gpl3/gcc/dist/gcc/config/sparc/sparc.cc#L1938-L1948
 
 (3) Earliest CPU model satisfy (2) seems `ultrasparc3`, IIUC:
 (I'm not familiar to sparc although...)
 
 https://github.com/NetBSD/src/blob/trunk/external/gpl3/gcc/dist/gcc/config/sparc/sparc.cc#L1766-L1767
 
 Actually, lib*san.so built with -mcpu=v8 contain undefined reference to
 __sync_val_compare_and_swap8, but they do not with -mcpu=ultrasparc3.
 
 Thanks,
 rin
 ----
 diff --git a/external/gpl3/gcc/lib/Makefile.sanitizer 
 b/external/gpl3/gcc/lib/Makefile.sanitizer
 index e574f902c22..e20693c3241 100644
 --- a/external/gpl3/gcc/lib/Makefile.sanitizer
 +++ b/external/gpl3/gcc/lib/Makefile.sanitizer
 @@ -128,7 +128,7 @@ COPTS.ubsan_init.cc += -O1
   # - 32-bit SPARC needs v8 to supply eg __sync_add_and_fetch_4
   # - i386 needs i586 for __sync_val_compare_and_swap_8.
   .if ${MACHINE_ARCH} == "sparc"
 -COPTS+= -mcpu=v8
 +COPTS+= -mcpu=ultrasparc3
   .endif
   .if ${MACHINE_ARCH} == "i386"
   COPTS+= -march=i586