From: Rich Felker <dalias@libc.org>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Nicholas Piggin <npiggin@gmail.com>,
libc-alpha@sourceware.org, musl@lists.openwall.com,
linuxppc-dev@lists.ozlabs.org, libc-dev@lists.llvm.org
Subject: Re: [musl] Powerpc Linux 'scv' system call ABI proposal take 2
Date: Thu, 16 Apr 2020 14:44:51 -0400 [thread overview]
Message-ID: <20200416184451.GB11469@brightrain.aerifal.cx> (raw)
In-Reply-To: <20200416183151.GA11469@brightrain.aerifal.cx>
On Thu, Apr 16, 2020 at 02:31:51PM -0400, Rich Felker wrote:
> > While on musl:
> >
> > 0000000000000000 <kill>:
> > 0: 48 83 ec 08 sub $0x8,%rsp
> > 4: 48 63 ff movslq %edi,%rdi
> > 7: 48 63 f6 movslq %esi,%rsi
> > a: b8 3e 00 00 00 mov $0x3e,%eax
> > f: 0f 05 syscall
> > 11: 48 89 c7 mov %rax,%rdi
> > 14: e8 00 00 00 00 callq 19 <kill+0x19>
> > 19: 5a pop %rdx
> > 1a: c3 retq
>
> Wow that's some extraordinarily bad codegen going on by gcc... The
> sign-extension is semantically needed and I don't see a good way
> around it (glibc's asm is kinda a hack taking advantage of kernel not
> looking at high bits, I think), but the gratuitous stack adjustment
> and refusal to generate a tail call isn't. I'll see if we can track
> down what's going on and get it fixed.
It seems to be https://gcc.gnu.org/bugzilla/show_bug.cgi?id=14441
which I've updated with a comment about the above.
Rich
next prev parent reply other threads:[~2020-04-16 18:44 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-15 21:45 Nicholas Piggin
2020-04-15 22:55 ` [musl] " Rich Felker
2020-04-16 0:16 ` Nicholas Piggin
2020-04-16 0:48 ` Rich Felker
2020-04-16 2:24 ` Nicholas Piggin
2020-04-16 2:35 ` Rich Felker
2020-04-16 2:53 ` Nicholas Piggin
2020-04-16 3:03 ` Rich Felker
2020-04-16 3:41 ` Nicholas Piggin
2020-04-16 20:18 ` Florian Weimer
2020-04-16 9:58 ` Szabolcs Nagy
2020-04-20 0:27 ` Nicholas Piggin
2020-04-20 1:29 ` Rich Felker
2020-04-20 2:08 ` Nicholas Piggin
2020-04-20 21:17 ` Szabolcs Nagy
2020-04-21 9:57 ` Florian Weimer
2020-04-16 15:21 ` Jeffrey Walton
2020-04-16 15:40 ` Rich Felker
2020-04-16 4:48 ` Florian Weimer
2020-04-16 15:35 ` Rich Felker
2020-04-16 16:42 ` Florian Weimer
2020-04-16 16:52 ` Rich Felker
2020-04-16 18:12 ` Florian Weimer
2020-04-16 23:02 ` Segher Boessenkool
2020-04-17 0:34 ` Rich Felker
2020-04-17 1:48 ` Segher Boessenkool
2020-04-17 8:34 ` Florian Weimer
2020-04-16 14:16 ` Adhemerval Zanella
2020-04-16 15:37 ` Rich Felker
2020-04-16 17:50 ` Adhemerval Zanella
2020-04-16 17:59 ` Rich Felker
2020-04-16 18:18 ` Adhemerval Zanella
2020-04-16 18:31 ` Rich Felker
2020-04-16 18:44 ` Rich Felker [this message]
2020-04-16 18:52 ` Adhemerval Zanella
2020-04-20 0:46 ` Nicholas Piggin
2020-04-20 1:10 ` Nicholas Piggin
2020-04-20 1:34 ` Rich Felker
2020-04-20 2:32 ` Nicholas Piggin
2020-04-20 4:09 ` Rich Felker
2020-04-20 4:31 ` Nicholas Piggin
2020-04-20 17:27 ` Rich Felker
2020-04-22 6:18 ` Nicholas Piggin
2020-04-22 6:29 ` Nicholas Piggin
2020-04-23 2:36 ` Rich Felker
2020-04-23 12:13 ` Adhemerval Zanella
2020-04-23 16:18 ` Rich Felker
2020-04-23 16:35 ` Adhemerval Zanella
2020-04-23 16:43 ` Rich Felker
2020-04-23 17:15 ` Adhemerval Zanella
2020-04-23 17:42 ` Rich Felker
2020-04-25 3:40 ` Nicholas Piggin
2020-04-25 4:52 ` Rich Felker
2020-04-25 3:30 ` Nicholas Piggin
2020-04-21 12:28 ` David Laight
2020-04-21 14:39 ` Rich Felker
2020-04-21 15:00 ` Adhemerval Zanella
2020-04-21 15:31 ` David Laight
2020-04-22 6:54 ` Nicholas Piggin
2020-04-22 7:15 ` [musl] " Florian Weimer
2020-04-22 7:31 ` Nicholas Piggin
2020-04-22 8:11 ` Florian Weimer
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