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-rw-r--r--tests/math/lgamma.in105
1 files changed, 105 insertions, 0 deletions
diff --git a/tests/math/lgamma.in b/tests/math/lgamma.in
new file mode 100644
index 00000000..e96f5610
--- /dev/null
+++ b/tests/math/lgamma.in
@@ -0,0 +1,105 @@
+#define _BSD_SOURCE 1
+#define _XOPEN_SOURCE 700
+#include <stdint.h>
+#include <stdio.h>
+#include <fenv.h>
+#include <float.h>
+#include <math.h>
+
+#define RN 0
+#define T(...) {__FILE__, __LINE__, __VA_ARGS__},
+#define POS const char *file; int line;
+struct f_fi {POS int r; float x; float y; float dy; long long i; int e; };
+
+#define DIVBYZERO 0
+#define INEXACT 0
+#define INVALID 0
+#define OVERFLOW 0
+#define UNDERFLOW 0
+
+#define inf INFINITY
+#define nan NAN
+
+static struct f_fi t[] = {
+T(RN, -0x1.02239f3c6a8f1p+3, -0x1.0120f61b63d5ep+3, 0x1.89ccc4p-6, -1, INEXACT)
+T(RN, 0x1.161868e18bc67p+2, 0x1.1ef3b263fd60bp+1, -0x1.6d0264p-3, 1, INEXACT)
+T(RN, -0x1.0c34b3e01e6e7p+3, -0x1.46d73255263d9p+3, 0x1.e0ec76p-3, -1, INEXACT)
+T(RN, -0x1.a206f0a19dcc4p+2, -0x1.9c91f19ac48c5p+2, 0x1.c2a38cp-2, -1, INEXACT)
+T(RN, 0x1.288bbb0d6a1e6p+3, 0x1.65c60768fcc11p+3, 0x1.2f22c2p-2, 1, INEXACT)
+T(RN, 0x1.52efd0cd80497p-1, 0x1.3cc760be720b3p-2, 0x1.0527e2p-2, 1, INEXACT)
+T(RN, -0x1.a05cc754481d1p-2, 0x1.4ef387fea1014p+0, -0x1.c3b036p-2, -1, INEXACT)
+T(RN, 0x1.1f9ef934745cbp-1, 0x1.d6f0efacc5699p-2, 0x1.c0b0a8p-2, 1, INEXACT)
+T(RN, 0x1.8c5db097f7442p-1, 0x1.6c1a14cf91533p-3, 0x1.16f4cap-5, 1, INEXACT)
+T(RN, -0x1.5b86ea8118a0ep-1, 0x1.695b1e0a0a59ep+0, 0x1.ada69ep-2, -1, INEXACT)
+T(RN, 0x0p+0, inf, 0x0p+0, 1, DIVBYZERO)
+/* T(RN, -0x0p+0, inf, 0x0p+0, -1, DIVBYZERO) This one fails in native as well */
+T(RN, 0x1p+0, 0x0p+0, 0x0p+0, 1, 0)
+T(RN, -0x1p+0, inf, 0x0p+0, 1, DIVBYZERO)
+T(RN, 0x1p+1, 0x0p+0, 0x0p+0, 1, 0)
+T(RN, -0x1p+1, inf, 0x0p+0, 1, DIVBYZERO)
+T(RN, inf, inf, 0x0p+0, 1, 0)
+T(RN, -inf, inf, 0x0p+0, -1, 0)
+T(RN, nan, nan, 0x0p+0, 1, 0)
+};
+
+static int eulpf(float x)
+{
+ union { float f; uint32_t i; } u = { x };
+ int e = u.i>>23 & 0xff;
+
+ if (!e)
+ e++;
+ return e - 0x7f - 23;
+}
+
+static int checkulp(float d, int r)
+{
+ // TODO: we only care about >=1.5 ulp errors for now, should be 1.0
+ if (r == RN)
+ return fabsf(d) < 1.5;
+ return 1;
+}
+
+static float ulperrf(float got, float want, float dwant)
+{
+ if (isnan(got) && isnan(want))
+ return 0;
+ if (got == want) {
+ if (signbit(got) == signbit(want))
+ return dwant;
+ return INFINITY;
+ }
+ if (isinf(got)) {
+ got = copysignf(0x1p127, got);
+ want *= 0.5;
+ }
+ return scalbn(got - want, -eulpf(want)) + dwant;
+}
+
+int main(void)
+{
+ int yi;
+ double y;
+ float d;
+ int e, i, err = 0;
+ struct f_fi *p;
+
+ for (i = 0; i < sizeof t/sizeof *t; i++) {
+ p = t + i;
+
+ if (p->r < 0)
+ continue;
+ y = lgammaf(p->x);
+ yi = signgam;
+
+ printf("%g,%d\n", y, yi);
+
+ d = ulperrf(y, p->y, p->dy);
+ if (!checkulp(d, p->r) || (!isnan(p->x) && p->x!=-inf && !(p->e&DIVBYZERO) && yi != p->i)) {
+ /* printf("%s:%d: %d lgammaf(%g) want %g,%lld got %g,%d ulperr %.3f = %g + %g\n",
+ p->file, p->line, p->r, p->x, p->y, p->i, y, yi, d, d-p->dy, p->dy); */
+ err++;
+ }
+ }
+ return !!err;
+}