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From: Richard Henderson <rth@twiddle.net>
To: Stefan Weil <sw@weilnetz.de>,
	Sergey Fedorov <sergey.fedorov@linaro.org>,
	qemu-devel@nongnu.org
Cc: "Alex Bennée" <alex.bennee@linaro.org>,
	"Sergey Fedorov" <serge.fdrv@gmail.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Peter Crosthwaite" <crosthwaite.peter@gmail.com>,
	"Michael Roth" <mdroth@linux.vnet.ibm.com>,
	"Peter Maydell" <peter.maydell@linaro.org>
Subject: Re: [Qemu-devel] [PATCH 01/11] tci: Fix build regression
Date: Thu, 7 Apr 2016 20:40:26 -0700	[thread overview]
Message-ID: <5707282A.5040701@twiddle.net> (raw)
In-Reply-To: <5706C506.5070607@weilnetz.de>

On 04/07/2016 01:37 PM, Stefan Weil wrote:
> I just tested a variant with tcg_debug_assert. It creates less efficient
> code when debugging is disabled. Here is the code size for x86_64:
>
> with normal tcg_debug_assert:
>
>     text       data        bss        dec        hex    filename
>     8293          0        128       8421       20e5
> bin/ndebug/x86_64-linux-gnu,tci/x86_64-softmmu/tci.o
>
> In gdb I can also see assembler code for op_size at the beginning
> of the for loop in tcg_qemu_tb_exec. This slows down the interpreter.

Please file a gcc bug.

A branch across __builtin_unreachable is supposed to fold to a simple 
compile-time assert, providing extra information to the compiler but not 
generating code.


r~

  reply	other threads:[~2016-04-08  3:40 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-07 15:53 [Qemu-devel] [PATCH 00/11] tcg: Make direct jump patching thread-safe Sergey Fedorov
2016-04-07 15:53 ` [Qemu-devel] [PATCH 01/11] tci: Fix build regression Sergey Fedorov
2016-04-07 18:15   ` Richard Henderson
2016-04-07 19:16     ` Stefan Weil
2016-04-07 20:37       ` Stefan Weil
2016-04-08  3:40         ` Richard Henderson [this message]
2016-04-07 15:53 ` [Qemu-devel] [PATCH 02/11] pc-bios/s390-ccw: Use correct strip when cross-compiling Sergey Fedorov
2016-04-07 16:18   ` Cornelia Huck
2016-04-07 16:22     ` Sergey Fedorov
2016-04-18 13:15     ` Sergey Fedorov
2016-04-18 14:51   ` Cornelia Huck
2016-04-18 15:34     ` Cornelia Huck
2016-04-18 15:47       ` Sergey Fedorov
2016-04-21 17:36         ` Sergey Fedorov
2016-04-21 17:49           ` Alex Bennée
2016-04-21 18:56             ` Sergey Fedorov
2016-04-22  8:08           ` Cornelia Huck
2016-05-09 12:49             ` Paolo Bonzini
2016-05-10 10:47               ` Sergey Fedorov
2016-04-07 15:53 ` [Qemu-devel] [PATCH 03/11] tci: Make direct jump patching thread-safe Sergey Fedorov
2016-04-20  9:42   ` Alex Bennée
2016-04-20 11:40     ` Sergey Fedorov
2016-04-20 13:14       ` Alex Bennée
2016-04-22 11:31         ` Sergey Fedorov
2016-04-22 12:49           ` Alex Bennée
2016-04-07 15:53 ` [Qemu-devel] [PATCH 04/11] tcg/ppc: " Sergey Fedorov
2016-04-20  9:49   ` Alex Bennée
2016-04-07 15:53 ` [Qemu-devel] [PATCH 05/11] tcg/i386: " Sergey Fedorov
2016-04-20  9:55   ` Alex Bennée
2016-04-20 11:43     ` Sergey Fedorov
2016-04-20 15:04     ` Richard Henderson
2016-04-20 16:15       ` Sergey Fedorov
2016-04-07 15:53 ` [Qemu-devel] [PATCH 06/11] tcg/s390: " Sergey Fedorov
2016-04-20 10:01   ` Alex Bennée
2016-04-20 11:45     ` Sergey Fedorov
2016-04-07 15:53 ` [Qemu-devel] [PATCH 07/11] tcg/arm: " Sergey Fedorov
2016-04-20 13:33   ` Alex Bennée
2016-04-20 14:29     ` Sergey Fedorov
2016-04-20 14:40       ` Alex Bennée
2016-04-20 16:12         ` Sergey Fedorov
2016-04-07 15:53 ` [Qemu-devel] [PATCH 08/11] tcg/aarch64: " Sergey Fedorov
2016-04-20 14:01   ` Alex Bennée
2016-04-20 15:08     ` Richard Henderson
2016-04-20 18:22       ` Alex Bennée
2016-04-20 18:57         ` Richard Henderson
2016-04-20 19:51           ` Alex Bennée
2016-04-20 18:44       ` Sergey Fedorov
2016-04-21 15:47   ` Sergey Fedorov
2016-04-07 15:53 ` [Qemu-devel] [PATCH 09/11] tcg/sparc: " Sergey Fedorov
2016-04-20 14:23   ` Alex Bennée
2016-04-07 15:53 ` [Qemu-devel] [PATCH 10/11] tcg/mips: " Sergey Fedorov
2016-04-07 16:01   ` Paolo Bonzini
2016-04-07 16:09     ` Sergey Fedorov
2016-04-07 15:53 ` [Qemu-devel] [PATCH 11/11] tcg: Note requirement on atomic direct jump patching Sergey Fedorov
2016-04-20 14:25   ` Alex Bennée
2016-04-07 15:56 ` [Qemu-devel] [PATCH 00/11] tcg: Make direct jump patching thread-safe Sergey Fedorov
2016-04-20  8:44 ` Alex Bennée

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