re: toolchain/58411: GCC/x86_64 10.5 and 12.4 miscompile GCC/sh3 12.4

[gnats-admin%netbsd.org@localhost]

The following reply was made to PR toolchain/58411; it has been noted by GNATS.

From: matthew green <mrg%eterna23.net@localhost>
To: rin%netbsd.org@localhost
Cc: gnats-bugs%netbsd.org@localhost, toolchain-manager%netbsd.org@localhost,
    gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: re: toolchain/58411: GCC/x86_64 10.5 and 12.4 miscompile GCC/sh3 12.4
Date: Sat, 17 Aug 2024 15:21:31 +1000

 Rin Okuyama writes:
 > On 2024/08/16 20:35, Rin Okuyama wrote:
 > > On 2024/08/11 17:07, matthew green wrote:
 > >> i've commited the main GCC 12.x sh fix to -current.
 > > 
 > > Thanks!!
 >
 > Also, I've tested netbsd-10 branch with this diff back-ported to
 > GCC 10.5; although no serious problem has been observed for GCC 10,
 > it can be, precisely depending on host-compiler behavior.
 >
 > There was no regression for full ATF. I will commit it for gcc.old,
 > and send pullup request to netbsd-10 with s/gcc.old/gcc/, if there's
 > no objection.
 
 for GCC 10 there shouldn't be a problem.
 
 the relevant function was changed from "int" to "bool" return
 between 10 and 12, but the sh backend had an awful ugly "extern"
 in the .cc file instead of including the right header. [*]
 
 so while the problem exist with GCC 10, the "awful ugly" part
 is at least identical and does not cause a problem.
 
 ie, i don't object to a pullup/etc but i don't think it matters.
 
 
 .mrg.
 
 [*] eg, on x86 this would cause the caller to check 32 bits of
     the register, when the callee now only set 8 bits.