Re: [RFC PATCH v4 00/29] Hexagon patch series - Philippe Mathieu-Daudé

From: "Philippe Mathieu-Daudé" <f4bug@amsat.org>
To: Taylor Simpson <tsimpson@quicinc.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: "ale@rev.ng" <ale@rev.ng>, Thomas Huth <thuth@redhat.com>,
	"riku.voipio@iki.fi" <riku.voipio@iki.fi>,
	"richard.henderson@linaro.org" <richard.henderson@linaro.org>,
	"laurent@vivier.eu" <laurent@vivier.eu>,
	"aleksandar.m.mail@gmail.com" <aleksandar.m.mail@gmail.com>
Subject: Re: [RFC PATCH v4 00/29] Hexagon patch series
Date: Tue, 29 Sep 2020 22:41:14 +0200	[thread overview]
Message-ID: <ae64a974-ad55-72b8-e484-ab9cb1f78a66@amsat.org> (raw)
In-Reply-To: <BYAPR02MB4886C114AAC9DDEF70300D23DE320@BYAPR02MB4886.namprd02.prod.outlook.com>

Cc'ing Eric/Thomas...

On 9/29/20 10:11 PM, Taylor Simpson wrote:
>> -----Original Message-----
>> From: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com> On
>> Behalf Of Philippe Mathieu-Daudé
>> Sent: Tuesday, September 29, 2020 11:02 AM
>> To: Taylor Simpson <tsimpson@quicinc.com>; qemu-devel@nongnu.org
>> Cc: ale@rev.ng; riku.voipio@iki.fi; richard.henderson@linaro.org;
>> laurent@vivier.eu; aleksandar.m.mail@gmail.com
>> Subject: Re: [RFC PATCH v4 00/29] Hexagon patch series
>>
>> QEMU aims to support the 2 latest releases of supported distributions.
>> From time to time a brave developer look at the different versions
>> packaged and make some cleanup in the code base. It used to be tedious,
>> now that repology.org exists it is a bit easier.
>>
>> The last effort is from Thomas, see commit efc6c070aca:
>>
>>     The supported distributions use the following version
>>     of GCC:
>>
>>           RHEL-7: 4.8.5
>>           Debian (Stretch): 6.3.0
>>           Debian (Jessie): 4.8.4
>>           OpenBSD (ports): 4.9.4
>>           FreeBSD (ports): 8.2.0
>>           OpenSUSE Leap 15: 7.3.1
>>           Ubuntu (Xenial): 5.3.1
>>           macOS (Homebrew): 8.2.0
>>
>>     So we can safely assume GCC 4.8 these days.
>>
>> This is the "mandated" compiler version.
> 
> Ouch!  4.8 is old enough that it doesn't support C11 _Generic which I am using.  That needs at least GCC 4.9.
> 
> Here are a couple of examples.  As you can see, _Generic is used to dispatch to slightly different TCG generation functions depending on the type of the operands.  I will scratch my head and figure out a different way to do this.
> 
> #define MEM_STORE1_FUNC(X) \
>     _Generic((X), int : gen_store1i, TCGv_i32 : gen_store1)
> #define MEM_STORE1(VA, DATA, SLOT) \
>     MEM_STORE1_FUNC(DATA)(cpu_env, VA, DATA, ctx, SLOT)
> 
> #define GETBYTE_FUNC(X) \
>     _Generic((X), TCGv_i32 : gen_get_byte, TCGv_i64 : gen_get_byte_i64)
> #define fGETBYTE(N, SRC) GETBYTE_FUNC(SRC)(BYTE, N, SRC, true)
> #define fGETUBYTE(N, SRC) GETBYTE_FUNC(SRC)(BYTE, N, SRC, false)
> 
> 
> FWIW, I have been using 5.5.
> 
> The errors you saw started around 7.5 and are easy to fix.
> 
> 
> Taylor
> 