[gnumeric] complex_gamma: switch to value api

[Morten Welinder <mortenw src gnome org>]

commit acd4dd6b8110b7fe7a8d9303239fd9af766140b2
Author: Morten Welinder <terra gnome org>
Date:   Fri Feb 12 22:35:25 2016 -0500

    complex_gamma: switch to value api

 plugins/fn-complex/functions.c |    5 +--
 src/sf-gamma.c                 |   43 +++++++++++++++++----------------------
 src/sf-gamma.h                 |    2 +-
 3 files changed, 22 insertions(+), 28 deletions(-)
---
diff --git a/plugins/fn-complex/functions.c b/plugins/fn-complex/functions.c
index c4eb41d..ac65297 100644
--- a/plugins/fn-complex/functions.c
+++ b/plugins/fn-complex/functions.c
@@ -1092,14 +1092,13 @@ static GnmFuncHelp const help_imgamma[] = {
 static GnmValue *
 gnumeric_imgamma (GnmFuncEvalInfo *ei, GnmValue const * const *argv)
 {
-       gnm_complex c, res;
+       gnm_complex c;
        char imunit;
 
        if (value_get_as_complex (argv[0], &c, &imunit))
                return value_new_error_NUM (ei->pos);
 
-       complex_gamma (&res, &c);
-       return value_new_complex (&res, imunit);
+       return value_new_complexv (gnm_complex_gamma (c), imunit);
 }
 
 /***************************************************************************/
diff --git a/src/sf-gamma.c b/src/sf-gamma.c
index 952c99c..0602168 100644
--- a/src/sf-gamma.c
+++ b/src/sf-gamma.c
@@ -1249,21 +1249,20 @@ static const guint32 lanczos_denom[G_N_ELEMENTS(lanczos_num)] = {
        13339535, 2637558, 357423, 32670, 1925, 66, 1
 };
 
-void
-complex_gamma (gnm_complex *dst, gnm_complex const *src)
+gnm_complex
+gnm_complex_gamma (gnm_complex src)
 {
-       if (gnm_complex_real_p (src)) {
-               gnm_complex_init (dst, gnm_gamma (src->re), 0);
-       } else if (src->re < 0) {
+       if (gnm_complex_real_p (&src)) {
+               return GNM_CREAL (gnm_gamma (src.re));
+       } else if (src.re < 0) {
                /* Gamma(z) = pi / (sin(pi*z) * Gamma(-z+1)) */
-               gnm_complex a, b, mz;
+               gnm_complex a, b;
 
-               gnm_complex_init (&mz, -src->re, -src->im);
-               a = gnm_complex_fact (mz);
+               a = gnm_complex_fact (GNM_CNEG (src));
 
                gnm_complex_init (&b,
-                             M_PIgnum * gnm_fmod (src->re, 2),
-                             M_PIgnum * src->im);
+                             M_PIgnum * gnm_fmod (src.re, 2),
+                             M_PIgnum * src.im);
                /* Hmm... sin overflows when b.im is large.  */
                gnm_complex_sin (&b, &b);
 
@@ -1271,7 +1270,7 @@ complex_gamma (gnm_complex *dst, gnm_complex const *src)
 
                gnm_complex_init (&b, M_PIgnum, 0);
 
-               gnm_complex_div (dst, &b, &a);
+               return GNM_CDIV (b, a);
        } else {
                gnm_complex zmh, zmhd2, zmhpg, f, f2, p, q, pq;
                int i;
@@ -1280,14 +1279,14 @@ complex_gamma (gnm_complex *dst, gnm_complex const *src)
                gnm_complex_init (&p, lanczos_num[i], 0);
                gnm_complex_init (&q, lanczos_denom[i], 0);
                while (--i >= 0) {
-                       gnm_complex_mul (&p, &p, src);
+                       gnm_complex_mul (&p, &p, &src);
                        p.re += lanczos_num[i];
-                       gnm_complex_mul (&q, &q, src);
+                       gnm_complex_mul (&q, &q, &src);
                        q.re += lanczos_denom[i];
                }
                gnm_complex_div (&pq, &p, &q);
 
-               gnm_complex_init (&zmh, src->re - 0.5, src->im);
+               gnm_complex_init (&zmh, src.re - 0.5, src.im);
                gnm_complex_init (&zmhpg, zmh.re + lanczos_g, zmh.im);
                gnm_complex_init (&zmhd2, zmh.re * 0.5, zmh.im * 0.5);
                gnm_complex_pow (&f, &zmhpg, &zmhd2);
@@ -1297,7 +1296,7 @@ complex_gamma (gnm_complex *dst, gnm_complex const *src)
                gnm_complex_mul (&f2, &f, &f2);
                gnm_complex_mul (&f2, &f2, &f);
 
-               gnm_complex_mul (dst, &f2, &pq);
+               return GNM_CMUL (f2, pq);
        }
 }
 
@@ -1309,13 +1308,9 @@ gnm_complex_fact (gnm_complex src)
        if (gnm_complex_real_p (&src)) {
                return GNM_CREAL (gnm_fact (src.re));
        } else {
-               /*
-                * This formula is valid for all arguments except zero
-                * which we conveniently handled above.
-                */
-               gnm_complex gz;
-               complex_gamma (&gz, &src);
-               return GNM_CMUL (gz, src);
+               // This formula is valid for all arguments except zero
+               // which we conveniently handled above.
+               return GNM_CMUL (gnm_complex_gamma (src), src);
        }
 }
 
@@ -1597,7 +1592,7 @@ fixup:
        // 1. Regularizing here is too late due to overflow.
        // 2. Upper/lower switch can have cancellation
        if (regularized != have_regularized) {
-               complex_gamma (&ga, a);
+               ga = gnm_complex_gamma (*a);
                have_ga = TRUE;
 
                if (have_regularized)
@@ -1613,7 +1608,7 @@ fixup:
                        res.im = 0 - res.im;
                } else {
                        if (!have_ga)
-                               complex_gamma (&ga, a);
+                               ga = gnm_complex_gamma (*a);
                        gnm_complex_sub (&res, &ga, &res);
                }
        }
diff --git a/src/sf-gamma.h b/src/sf-gamma.h
index 815b1f1..0ea7e99 100644
--- a/src/sf-gamma.h
+++ b/src/sf-gamma.h
@@ -10,7 +10,7 @@ gnm_float stirlerr(gnm_float n);
 gnm_float gnm_gamma (gnm_float x);
 gnm_float gnm_fact (gnm_float x);
 int       qfactf (gnm_float x, GnmQuad *mant, int *exp2);
-void complex_gamma (gnm_complex *dst, gnm_complex const *src);
+gnm_complex gnm_complex_gamma (gnm_complex src);
 gnm_complex gnm_complex_fact (gnm_complex src);
 void complex_igamma (gnm_complex *dst, gnm_complex const  *a, gnm_complex const *z,
                     gboolean lower, gboolean regularized);