Thank you Herman
-----Original Message-----
From: Tinycc-devel [mailto:tinycc-devel-bounces+eligis=orange...@nongnu.org] On
Behalf Of Herman ten Brugge via Tinycc-devel
Sent: Tuesday, October 29, 2019 12:06
To: tinycc-devel@nongnu.org
Cc: Herman ten Brugge
Subject: Re: [Tinycc-devel] SSE calling convention bug
Done,
Herman
On 2019-10-29 10:57, Christian Jullien wrote:
> Sorry if I annoy you with details.
>
> I just want to say that you added a pure C test that should work in any cases
> whether backend uses sse or not.
> It appears that it was broken when sse is used (as different tests could also
> break on different architecture).
> My own opinion, is that generic test names should not be named using a given
> backend.
>
> As your test case is related to passing floats that why I suggest to move it
> to 22_floating_point C generic code with comment that explains it uses to
> fail with sse. But something like 109_float_struct_calling also works for me.
>
> It is curious to see 109_sse_calling on ARM 32/64. One wonder what this test
> could do on ARM?
>
> I can also leave with '109_sse_calling'
>
> C.
>
>
>
> -----Original Message-----
> From: Tinycc-devel [mailto:tinycc-devel-bounces+eligis=orange...@nongnu.org]
> On Behalf Of Herman ten Brugge via Tinycc-devel
> Sent: Tuesday, October 29, 2019 10:37
> To: tinycc-devel@nongnu.org
> Cc: Herman ten Brugge
> Subject: Re: [Tinycc-devel] SSE calling convention bug
>
> Do you mean that I should call the testcase '109_calling.c' and add a
> comment in this file that this is for x86_64 sse calling?
>
> This is why I called the file '109_sse_calling.c'.
>
> The file name indicates that this is only solving a bug for x86_64.
>
> Herman
>
>
>
> On 2019-10-29 08:04, Christian Jullien wrote:
>> Than you for your recent patch on mod.
>>
>> I just have a little remark about ' 109_sse_calling' file name.
>> This new test is executed also on Windows and arm32/64 (which is fine).
>> However, those backend don't use sse.
>> IMHO, this test should not have sse in its name but a comment could explain
>> that the test revealed a bug when see is used as with Linux.
>>
>> Another solution is to add this new test in 22_floating_point + comment
>> about sse
>>
>> -----Original Message-----
>> From: Tinycc-devel [mailto:tinycc-devel-bounces+eligis=orange...@nongnu.org]
>> On Behalf Of Michael Matz
>> Sent: Monday, October 28, 2019 10:32
>> To: Herman ten Brugge via Tinycc-devel
>> Cc: Herman ten Brugge
>> Subject: *** SPAM *** Re: [Tinycc-devel] SSE calling convention bug
>>
>> Hi,
>>
>> On Sun, 27 Oct 2019, Herman ten Brugge via Tinycc-devel wrote:
>>
>>> Look like the code in x86_64-gen.c is wrong. It should read:
>>>
>>> if (sse_reg) { /* avoid redundant movaps %xmm0, %xmm0
>>> */
>>> /* movaps %xmm1, %xmmN */
>>> o(0x280f);
>>> o(0xc1 + ((sse_reg+1) << 3));
>>> /* movaps %xmm0, %xmmN */
>>> o(0x280f);
>>> o(0xc0 + (sse_reg << 3));
>>> }
>> Yes.
>>
>>
>> Ciao,
>> Michael.
>>
>>> The problem occurs when sse_reg == 1. Because then xmm1 is overwritten
>>> before it is copied.
>>>
>>> Herman
>>>
>>> On 2019-10-27 07:32, Christian Jullien wrote:
>>>> Trying your sample with mod on Windows -m64/-m32 I get:
>>>>
>>>> c: >tcc -m32 foo.c && foo
>>>> 5.000000
>>>>
>>>> c:>tcc -m64 foo.c && foo
>>>> 5.000000
>>>>
>>>> It only return 3.0000 on Linux x64 (I've not tested your code on Linux
>>>> x86).
>>>>
>>>> C.
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: Tinycc-devel
>>>> [mailto:tinycc-devel-bounces+eligis=orange...@nongnu.org]
>>>> On Behalf Of Shachaf Ben-Kiki
>>>> Sent: Saturday, October 26, 2019 12:59
>>>> To: tinycc-devel@nongnu.org
>>>> Subject: [Tinycc-devel] SSE calling convention bug
>>>>
>>>> Hello,
>>>>
>>>> I ran into a bug in the SSE function call code in x86_64-gen.c. It's
>>>> in the following lines, in gfunc_call:
>>>>
>>>> if (sse_reg) { /* avoid redundant movaps %xmm0, %xmm0 */
>>>> /* movaps %xmm0, %xmmN */
>>>> o(0x280f);
>>>> o(0xc0 + (sse_reg << 3));
>>>> /* movaps %xmm1, %xmmN */
>>>> o(0x280f);
>>>> o(0xc1 + ((sse_reg+1) << 3));
>>>> }
>>>>
>>>> When sse_reg is %xmm1, this generates
>>>>
>>>> 0f 28 c8 movaps %xmm0,%xmm1
>>>> 0f 28 d1 movaps %xmm1,%xmm2
>>>>
>>>> Such that the first mov overwrites xmm1 before the second mov uses it.
>>>> Since the registers are used in reverse order and only one or two at
>>>> a time, I think swapping the order of the movs should be sufficient
>>>> to fix it.
>>>>
>>>> Here's a test case:
>>>>
>>>> #include <stdio.h>
>>>>
>>>> struct Point {
>>>> float x;
>>>> float y;
>>>> };
>>>>
>>>> struct Rect {
>>>> struct Point top_left;
>>>> struct Point size;
>>>> };
>>>>
>>>> float foo(struct Point p, struct Rect r) {
>>>> return r.size.x;
>>>> }
>>>>
>>>> int main(int argc, char **argv) {
>>>> struct Point p = {1, 2};
>>>> struct Rect r = {{3, 4}, {5, 6}};
>>>> printf("%f\n", foo(p, r));
>>>> return 0;
>>>> }
>>>>
>>>> This program should print 5, but it prints 3 in tcc.
>>>>
>>>> Is this the right place to post this? I can post it elsewhere, or
>>>> send a patch (it took a while to track this down but I think the fix
>>>> should be easy).
>>>>
>>>> Thanks,
>>>> Shachaf
>>>>
>>>> _______________________________________________
>>>> Tinycc-devel mailing list
>>>> Tinycc-devel@nongnu.org
>>>> https://lists.nongnu.org/mailman/listinfo/tinycc-devel
>>>>
>>>>
>>> _______________________________________________
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>>>
>>>
>
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