LGTM.
-- Jeff J.
On Tue, Nov 8, 2022 at 1:31 PM Thomas Schwinge
wrote:
> ..., not just '#if defined(__CYGWIN__)'. (Exception: 'clog10l' which
> currently
> indeed is for Cygwin only.)
>
> This completes 2017-07-05 commit be3ca3947402827aa52709e677369bc7ad30aa1d
> "Fixed warnings for some long double complex methods" after Aditya
> Upadhyay's
> work on importing "Long double complex methods" from NetBSD.
>
> For example, this changes GCC/nvptx libgfortran 'configure' output as
> follows:
>
> [...]
> checking for ccosf... yes
> checking for ccos... yes
> checking for ccosl... [-no-]{+yes+}
> [...]
>
> ..., and correspondingly GCC/nvptx 'nvptx-none/libgfortran/config.h' as
> follows:
>
> [...]
> /* Define to 1 if you have the `ccosl' function. */
> -/* #undef HAVE_CCOSL */
> +#define HAVE_CCOSL 1
> [...]
>
> Similarly for 'ccoshl', 'cexpl', 'cpowl', 'csinl', 'csinhl', 'ctanl',
> 'ctanhl',
> 'cacoshl', 'cacosl', 'casinhl', 'catanhl'. ('conjl', 'cprojl' are not
> currently being used in libgfortran.)
>
> This in turn simplifies GCC/nvptx 'libgfortran/intrinsics/c99_functions.c'
> compilation such that this files doesn't have to provide its own
> "Implementation of various C99 functions" for those, when in fact they're
> available in newlib libm.
> ---
>
> A few more words on why this is relevant for GCC.
>
> For example, 'cexpl' usually is provided by libm, but if it isn't, the
> open-coded replacement function in
> 'libgfortran/intrinsics/c99_functions.c' is effective if it holds that
> 'defined(HAVE_COSL) && defined(HAVE_SINL) && defined(HAVE_EXPL)':
>
> long double complex
> cexpl (long double complex z)
> {
> long double a, b;
> long double complex v;
>
> a = REALPART (z);
> b = IMAGPART (z);
> COMPLEX_ASSIGN (v, cosl (b), sinl (b));
> return expl (a) * v;
> }
>
> This replacement code is active for current GCC/nvptx (... if no longer
> compiling GCC/nvptx libgfortran in "minimal" mode, 'LIBGFOR_MINIMAL',
> which I'm currently working on).
>
> Comparing the preceeding to the 'c99_functions.c.188t.sincos' dump, we see
> for
> that function:
>
> __attribute__((nothrow, leaf, const))
> complex long double cexpl (complex long double z)
> {
>long double b;
>long double a;
>long double _1;
>long double _2;
>long double _4;
>long double _5;
>long double _11;
> + complex long double sincostmp_13;
>
> [local count: 1073741824]:
>a_7 = REALPART_EXPR ;
>b_8 = IMAGPART_EXPR ;
> - _1 = cosl (b_8);
> - _2 = sinl (b_8);
> + sincostmp_13 = __builtin_cexpil (b_8);
> + _1 = REALPART_EXPR ;
> + _2 = IMAGPART_EXPR ;
>_11 = expl (a_7);
>_4 = _1 * _11;
>_5 = _2 * _11;
>REALPART_EXPR <> = _4;
>IMAGPART_EXPR <> = _5;
>return ;
>
> }
>
> That is, the 'cosl (b)', 'sinl (b)' sequence is replaced by
> '__builtin_cexpil'. That '__builtin_cexpil' is then later mapped back
> into: 'cexpl'. We've now got an infinitely-recursive 'cexpl' replacement
> function, "implemented via itself"; GCC/nvptx libgfortran assumes there
> is no 'cexpl' in libm, whereas this 'sincos' transformation does assume
> that there is. (..., which looks like an additional bug on its own.)
>
> At the PTX-level, this leads to the following:
>
> [...]
> // BEGIN GLOBAL FUNCTION DECL: cexpl
> .visible .func cexpl (.param.u64 %in_ar0, .param.f64 %in_ar1,
> .param.f64 %in_ar2);
>
> // BEGIN GLOBAL FUNCTION DEF: cexpl
> .visible .func cexpl (.param.u64 %in_ar0, .param.f64 %in_ar1,
> .param.f64 %in_ar2)
> {
> [...]
> call cexpl, (%out_arg1, %out_arg2, %out_arg3);
> [...]
> ret;
> }
>
> [...]
> // BEGIN GLOBAL FUNCTION DECL: cexpl
> .extern .func cexpl (.param.u64 %in_ar0, .param.f64 %in_ar1,
> .param.f64 %in_ar2);
> [...]
>
> We see the '.visible .func cexpl' declaration and definition for the
> libgfortran replacement function and in the same compilation unit also
> the '.extern .func cexpl' declaration that implicitly gets introduced via
> the 'sincos' transformation (via the GCC/nvptx back end emitting an
> explicit declaration of any function referenced), and 'ptxas' then
> (rightfully so) complains about that mismatch:
>
> ptxas c99_functions.o, line 35; error : Inconsistent redefinition of
> variable 'cexpl'
> ptxas fatal : Ptx assembly aborted due to errors
> nvptx-as: ptxas returned 255 exit status
> make[2]: *** [c99_functions.lo] Error 1
>
> ---
> newlib/libc/include/complex.h | 35 ---
> 1 file changed, 16 insertions(+), 19 deletions(-)
>
> diff --git a/newlib/libc/include/complex.h b/newlib/libc/include/complex.h
> index 0a3ea97ed..ad3028e4c 100644
> --- a/newlib/libc/include/complex.h
> +++ b/newlib/libc/include/complex.h
> @@ -20,6 +2
