msvcrt: Import j0 implementation from musl.

Signed-off-by: Piotr Caban <piotr@codeweavers.com> Signed-off-by: Alexandre Julliard <julliard@winehq.org>

msvcrt: Import j0 implementation from musl.
c739e222 · Piotr Caban · Alexandre Julliard · e9f0fc12 · c739e222 · c739e222
Commit c739e222 authored Apr 28, 2021 by Piotr Caban Committed by Alexandre Julliard Apr 28, 2021
6 changed files
--- a/configure
+++ b/configure
@@ -19630,7 +19630,6 @@ for ac_func in \
 	expm1f \
 	fma \
 	fmaf \
-	j0 \
 	j1 \
 	jn \
 	lgamma \

--- a/configure.ac
+++ b/configure.ac
@@ -2674,7 +2674,6 @@ AC_CHECK_FUNCS(\
 	expm1f \
 	fma \
 	fmaf \
-	j0 \
 	j1 \
 	jn \
 	lgamma \

--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -2434,13 +2434,245 @@ int CDECL _isnan(double num)
    return (u.i & ~0ull >> 1) > 0x7ffull << 52;
 }
+static double pzero(double x)
+{
+    static const double pR8[6] = { /* for x in [inf, 8]=1/[0,0.125] */
+        0.00000000000000000000e+00,
+        -7.03124999999900357484e-02,
+        -8.08167041275349795626e+00,
+        -2.57063105679704847262e+02,
+        -2.48521641009428822144e+03,
+        -5.25304380490729545272e+03,
+    }, pS8[5] = {
+        1.16534364619668181717e+02,
+        3.83374475364121826715e+03,
+        4.05978572648472545552e+04,
+        1.16752972564375915681e+05,
+        4.76277284146730962675e+04,
+    }, pR5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */
+        -1.14125464691894502584e-11,
+        -7.03124940873599280078e-02,
+        -4.15961064470587782438e+00,
+        -6.76747652265167261021e+01,
+        -3.31231299649172967747e+02,
+        -3.46433388365604912451e+02,
+    }, pS5[5] = {
+        6.07539382692300335975e+01,
+        1.05125230595704579173e+03,
+        5.97897094333855784498e+03,
+        9.62544514357774460223e+03,
+        2.40605815922939109441e+03,
+    }, pR3[6] = {/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */
+        -2.54704601771951915620e-09,
+        -7.03119616381481654654e-02,
+        -2.40903221549529611423e+00,
+        -2.19659774734883086467e+01,
+        -5.80791704701737572236e+01,
+        -3.14479470594888503854e+01,
+    }, pS3[5] = {
+        3.58560338055209726349e+01,
+        3.61513983050303863820e+02,
+        1.19360783792111533330e+03,
+        1.12799679856907414432e+03,
+        1.73580930813335754692e+02,
+    }, pR2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */
+        -8.87534333032526411254e-08,
+        -7.03030995483624743247e-02,
+        -1.45073846780952986357e+00,
+        -7.63569613823527770791e+00,
+        -1.11931668860356747786e+01,
+        -3.23364579351335335033e+00,
+    }, pS2[5] = {
+        2.22202997532088808441e+01,
+        1.36206794218215208048e+02,
+        2.70470278658083486789e+02,
+        1.53875394208320329881e+02,
+        1.46576176948256193810e+01,
+    };
+    const double *p, *q;
+    double z, r, s;
+    uint32_t ix;
+    ix = *(ULONGLONG*)&x >> 32;
+    ix &= 0x7fffffff;
+    if (ix >= 0x40200000) {
+        p = pR8;
+        q = pS8;
+    } else if (ix >= 0x40122E8B) {
+        p = pR5;
+        q = pS5;
+    } else if (ix >= 0x4006DB6D) {
+        p = pR3;
+        q = pS3;
+    } else /*ix >= 0x40000000*/ {
+        p = pR2;
+        q = pS2;
+    }
+    z = 1.0 / (x * x);
+    r = p[0] + z * (p[1] + z * (p[2] + z * (p[3] + z * (p[4] + z * p[5]))));
+    s = 1.0 + z * (q[0] + z * (q[1] + z * (q[2] + z * (q[3] + z * q[4]))));
+    return 1.0 + r / s;
+}
+static double qzero(double x)
+{
+    static const double qR8[6] = { /* for x in [inf, 8]=1/[0,0.125] */
+        0.00000000000000000000e+00,
+        7.32421874999935051953e-02,
+        1.17682064682252693899e+01,
+        5.57673380256401856059e+02,
+        8.85919720756468632317e+03,
+        3.70146267776887834771e+04,
+    }, qS8[6] = {
+        1.63776026895689824414e+02,
+        8.09834494656449805916e+03,
+        1.42538291419120476348e+05,
+        8.03309257119514397345e+05,
+        8.40501579819060512818e+05,
+        -3.43899293537866615225e+05,
+    }, qR5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */
+        1.84085963594515531381e-11,
+        7.32421766612684765896e-02,
+        5.83563508962056953777e+00,
+        1.35111577286449829671e+02,
+        1.02724376596164097464e+03,
+        1.98997785864605384631e+03,
+    }, qS5[6] = {
+        8.27766102236537761883e+01,
+        2.07781416421392987104e+03,
+        1.88472887785718085070e+04,
+        5.67511122894947329769e+04,
+        3.59767538425114471465e+04,
+        -5.35434275601944773371e+03,
+    }, qR3[6] = {/* for x in [4.547,2.8571]=1/[0.2199,0.35001] */
+        4.37741014089738620906e-09,
+        7.32411180042911447163e-02,
+        3.34423137516170720929e+00,
+        4.26218440745412650017e+01,
+        1.70808091340565596283e+02,
+        1.66733948696651168575e+02,
+    }, qS3[6] = {
+        4.87588729724587182091e+01,
+        7.09689221056606015736e+02,
+        3.70414822620111362994e+03,
+        6.46042516752568917582e+03,
+        2.51633368920368957333e+03,
+        -1.49247451836156386662e+02,
+    }, qR2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */
+        1.50444444886983272379e-07,
+        7.32234265963079278272e-02,
+        1.99819174093815998816e+00,
+        1.44956029347885735348e+01,
+        3.16662317504781540833e+01,
+        1.62527075710929267416e+01,
+    }, qS2[6] = {
+        3.03655848355219184498e+01,
+        2.69348118608049844624e+02,
+        8.44783757595320139444e+02,
+        8.82935845112488550512e+02,
+        2.12666388511798828631e+02,
+        -5.31095493882666946917e+00,
+    };
+    const double *p, *q;
+    double s, r, z;
+    unsigned int ix;
+    ix = *(ULONGLONG*)&x >> 32;
+    ix &= 0x7fffffff;
+    if (ix >= 0x40200000) {
+        p = qR8;
+        q = qS8;
+    } else if (ix >= 0x40122E8B) {
+        p = qR5;
+        q = qS5;
+    } else if (ix >= 0x4006DB6D) {
+        p = qR3;
+        q = qS3;
+    } else /*ix >= 0x40000000*/ {
+        p = qR2;
+        q = qS2;
+    }
+    z = 1.0 / (x * x);
+    r = p[0] + z * (p[1] + z * (p[2] + z * (p[3] + z * (p[4] + z * p[5]))));
+    s = 1.0 + z * (q[0] + z * (q[1] + z * (q[2] + z * (q[3] + z * (q[4] + z * q[5])))));
+    return (-0.125 + r / s) / x;
+}
+/* j0 and y0 approximation for |x|>=2 */
+static double j0_y0_approx(unsigned int ix, double x, BOOL y0)
+{
+    static const double invsqrtpi = 5.64189583547756279280e-01;
+    double s, c, ss, cc, z;
+    s = sin(x);
+    c = cos(x);
+    if (y0) c = -c;
+    cc = s + c;
+    /* avoid overflow in 2*x, big ulp error when x>=0x1p1023 */
+    if (ix < 0x7fe00000) {
+        ss = s - c;
+        z = -cos(2 * x);
+        if (s * c < 0) cc = z / ss;
+        else ss = z / cc;
+        if (ix < 0x48000000) {
+            if (y0) ss = -ss;
+            cc = pzero(x) * cc - qzero(x) * ss;
+        }
+    }
+    return invsqrtpi * cc / sqrt(x);
+}
 /*********************************************************************
 *		_j0 (MSVCRT.@)
+ *
+ * Copied from musl: src/math/j0.c
 */
-double CDECL _j0(double num)
+double CDECL _j0(double x)
 {
-  /* FIXME: errno handling */
+    static const double R02 =  1.56249999999999947958e-02,
-  return unix_funcs->j0( num );
+            R03 = -1.89979294238854721751e-04,
+            R04 =  1.82954049532700665670e-06,
+            R05 = -4.61832688532103189199e-09,
+            S01 =  1.56191029464890010492e-02,
+            S02 =  1.16926784663337450260e-04,
+            S03 =  5.13546550207318111446e-07,
+            S04 =  1.16614003333790000205e-09;
+    double z, r, s;
+    unsigned int ix;
+    ix = *(ULONGLONG*)&x >> 32;
+    ix &= 0x7fffffff;
+    /* j0(+-inf)=0, j0(nan)=nan */
+    if (ix >= 0x7ff00000)
+        return math_error(_DOMAIN, "_j0", x, 0, 1 / (x * x));
+    x = fabs(x);
+    if (ix >= 0x40000000) {  /* |x| >= 2 */
+        /* large ulp error near zeros: 2.4, 5.52, 8.6537,.. */
+        return j0_y0_approx(ix, x, FALSE);
+    }
+    if (ix >= 0x3f200000) {  /* |x| >= 2**-13 */
+        /* up to 4ulp error close to 2 */
+        z = x * x;
+        r = z * (R02 + z * (R03 + z * (R04 + z * R05)));
+        s = 1 + z * (S01 + z * (S02 + z * (S03 + z * S04)));
+        return (1 + x / 2) * (1 - x / 2) + z * (r / s);
+    }
+    /* 1 - x*x/4 */
+    /* prevent underflow */
+    /* inexact should be raised when x!=0, this is not done correctly */
+    if (ix >= 0x38000000)  /* |x| >= 2**-127 */
+        x = 0.25 * x * x;
+    return 1 - x;
 }
 /*********************************************************************

--- a/dlls/msvcrt/unixlib.c
+++ b/dlls/msvcrt/unixlib.c
@@ -402,19 +402,6 @@ static float CDECL unix_hypotf(float x, float y)
 }
 /*********************************************************************
- *      j0
- */
-static double CDECL unix_j0(double num)
-{
-#ifdef HAVE_J0
-    return j0(num);
-#else
-    FIXME("not implemented\n");
-    return 0;
-#endif
-}
-/*********************************************************************
 *      j1
 */
 static double CDECL unix_j1(double num)
@@ -1053,7 +1040,6 @@ static const struct unix_funcs funcs =
    unix_frexpf,
    unix_hypot,
    unix_hypotf,
-    unix_j0,
    unix_j1,
    unix_jn,
    unix_ldexp,

--- a/dlls/msvcrt/unixlib.h
+++ b/dlls/msvcrt/unixlib.h
@@ -57,7 +57,6 @@ struct unix_funcs
    float           (CDECL *frexpf)(float x, int *exp);
    double          (CDECL *hypot)(double x, double y);
    float           (CDECL *hypotf)(float x, float y);
-    double          (CDECL *j0)(double num);
    double          (CDECL *j1)(double num);
    double          (CDECL *jn)(int n, double num);
    double          (CDECL *ldexp)(double x, int exp);

--- a/include/config.h.in
+++ b/include/config.h.in
@@ -288,9 +288,6 @@
 /* Define to 1 if you have the `isnan' function. */
 #undef HAVE_ISNAN
-/* Define to 1 if you have the `j0' function. */
-#undef HAVE_J0
 /* Define to 1 if you have the `j1' function. */
 #undef HAVE_J1