Le 20/01/2017 à 20:01, Matt Wette a écrit :
>
>> On Jan 19, 2017, at 7:01 PM, Matt Wette <matt.wette@gmail.com 
>> <mailto:matt.wette@gmail.com>> wrote:
>>
>>
>>> On Jan 18, 2017, at 6:26 PM, Andy Wingo <wingo@pobox.com 
>>> <mailto:wingo@pobox.com>> wrote:
>>>
>>> We are pleased to announce GNU Guile release 2.1.6.
>>>
>>> Guile 2.1.6 is the sixth pre-release in what will eventually become the
>>> 2.2 release series.  We encourage you to test this release and provide
>>> feedback to guile-devel@gnu.org <mailto:guile-devel@gnu.org>.
>>
>> Saw this one last round.  Mac OS, now gcc-6.3.0:
>>
>> ;;; ("#i1@-0" 1.0 -0.0)
>> FAIL: numbers.test: string->number: valid complex number strings
>>
>> I am going to see if I can generate the assembly.
>
> Short story: scm_c_make_polar is broken for the Mac.  Guile needs to 
> decide if it want to use __sincos() on Mac, or suppress optimization, 
> or ...
>
> I was able to get the above to work (guile-2.1.5) by using
>  SCM
> +#ifdef __APPLE__
> +__attribute__((optimize("O0")))
> +#endif
>  scm_c_make_polar (double mag, double ang)
>
>
> In scm_c_make_polar, “gcc -O2”  turns sin(), cos() into cexp(), since 
> cexp(i*x) = cos(x) + i*sin(x):
>
> gcc -O0 =>
> LM4339:
> movq-32(%rbp), %rax
> movd%rax, %xmm0
> call_sin
> movd%xmm0, %rax
> movq%rax, -8(%rbp)
> LM4340:
> movq-32(%rbp), %rax
> movd%rax, %xmm0
> call_cos
> movd%xmm0, %rax
> movq%rax, -16(%rbp)
>
> gcc -O2 =>
> pxor%xmm0, %xmm0
> LVL2703:
> call_cexp
>
> I wrote a little C program to show that cexp() does not preserve the 
> zero-signed-ness:
>
>  cos,sin: +1.000000 -0.000000
> __sincos: +1.000000 -0.000000
>     cexp: +1.000000 +0.000000
>
> The scm_c_make_polar will use sincos() if available, but macOS does 
> not have sincos(), it has __sincos().
>
> #include <stdio.h>
> #include <stdint.h>
> #include <math.h>
> #include <complex.h>
>
> extern double z, p, n;
>
> int main() {
>   double complex c;
>   double d, sine, cosine;
>
>   d = z*n;
>   printf(" cos,sin: %+f %+f\n", cos(d), sin(d));
>   __sincos(d, &sine, &cosine);
>   printf("__sincos: %+f %+f\n", cosine, sine);
>   c = cexp(CMPLX(0.0, d));
>   printf("    cexp: %+f %+f\n", creal(c), cimag(c));
> }
>
> double z = 0.0, p = +1.0, n = -1.0;
>
> Incidentally, the above program will not compile on my machine w/ 
> gcc-6.3.0.  “gcc -std=c11” or “gcc -std=c99” will not recognize the 
> standard macro CMPLX().
>
>
>
wow!