cpp /usr/include/threads.h fails; modfl segfaults
Brian Inglis
Brian.Inglis@SystematicSw.ab.ca
Mon Aug 31 15:37:36 GMT 2020
On 2020-08-31 01:35, Corinna Vinschen wrote:
> On Aug 30 14:39, Brian Inglis wrote:
>> On 2020-08-30 07:00, Corinna Vinschen wrote:
>>> On Aug 29 08:52, airplanemath via Cygwin wrote:
>>>> I have two reports. A brief description of the system:
>>>> $ uname -a | sed "s/${HOSTNAME}/\${HOSTNAME}/g"
>>>> CYGWIN_NT-10.0 ${HOSTNAME} 3.1.7(0.340/5/3) 2020-08-22 17:48 x86_64 Cygwin
>> ...
>>>> $ cat test.c
>>>> #include <math.h>
>>>> #include <stdio.h>
>>>> #include <stdlib.h>
>>>>
>>>> int main(int argc, char *argv[]) {
>>>> long double a, b, c;
>>>> char *num_end = NULL;
>>>> a = b = c = 0.0L;
>>>> if (argc != 2) {
>>>> fprintf(stderr, "Usage: %s NUMBER\n", argv[0]);
>>>> exit(1);
>>>> }
>>>> a = strtold(argv[1], &num_end);
>>>> b = modfl(a, &c);
>>>> printf("%Lf %Lf %Lf\n", a, b, c);
>>>> return 0;
>>>> }
>>>
>>> This is a bug in the assembler code taken from Mingw-w64. The bug has
>>> been fixed upstream, so I just pulled in the upstream fixes.
>>
>> The 64 bit fix doesn't pop eax but *now* flags eax as clobbered, whereas the 32
>> bit fix both pops and *now* flags eax as clobbered, which it really doesn't need
>> to do. Is this inconsistent treatment correct?
>
> You may be right that this is not necessary on i686, but it doesn't
> hurt either and I'd like to stick to the upstream code if possible.
The upstream patch changed only amd64/x86_64 code sequences for multiple modules
including modfl, and left i386/x86 untouched for those modules.
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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