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authorKacper <kacper@mail.openlinux.dev>2025-12-09 19:20:15 +0100
committerKacper <kacper@mail.openlinux.dev>2025-12-09 19:20:15 +0100
commit885f5974cdf65b59415837ae97f5a14ef1350670 (patch)
tree66ac13de29c7f4932c5fcae11773df574e4e256a /lib/libm/csqrtl.c
parent8f9e448b2ef6db7cd905540c21f3c5b190e7a1e7 (diff)
feat: add gzip and new headers
Diffstat (limited to 'lib/libm/csqrtl.c')
-rw-r--r--lib/libm/csqrtl.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/lib/libm/csqrtl.c b/lib/libm/csqrtl.c
new file mode 100644
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--- /dev/null
+++ b/lib/libm/csqrtl.c
@@ -0,0 +1,62 @@
+#include <stdbool.h>
+#include <float.h>
+#include "__complex.h"
+
+#define THRESH (LDBL_MAX / 2.414213562373095048801688724209698L)
+#define cpackl(r, i) ((r) + (i) * (long double complex)I)
+
+long double complex csqrtl(long double complex z)
+{
+ long double complex result;
+ long double a, b;
+ long double t;
+ bool scale;
+ a = creall(z);
+ b = cimagl(z);
+ /* Handle special cases. */
+ if (z == 0.0L)
+ return (cpackl((long double)0.0L, b));
+ if (isinf(b))
+ return (cpackl((long double)INFINITY, b));
+ if (isnan(a)) {
+ t = (b - b) / (b - b); /* raise invalid if b is not a NaN */
+ return (cpackl(a, t)); /* return NaN + NaN i */
+ }
+ if (isinf(a)) {
+ /*
+ * csqrt(inf + NaN i) = inf + NaN i
+ * csqrt(inf + y i) = inf + 0 i
+ * csqrt(-inf + NaN i) = NaN +- inf i
+ * csqrt(-inf + y i) = 0 + inf i
+ */
+ if (signbit(a))
+ return (cpackl(fabsl(b - b), copysignl(a, b)));
+ else
+ return (cpackl(a, copysignl(b - b, b)));
+ }
+ /*
+ * The remaining special case (b is NaN) is handled just fine by
+ * the normal code path below.
+ */
+ /* Scale to avoid overflow. */
+ if (fabsl(a) >= THRESH || fabsl(b) >= THRESH) {
+ a *= 0.25L;
+ b *= 0.25L;
+ scale = true;
+ } else {
+ scale = false;
+ }
+ /* Algorithm 312, CACM vol 10, Oct 1967. */
+ if (a >= 0L) {
+ t = sqrtl((a + hypotl(a, b)) * 0.5L);
+ result = cpackl(t, b / (2.0L * t));
+ } else {
+ t = sqrtl((-a + hypotl(a, b)) * 0.5L);
+ result = cpackl(fabsl(b) / (2.0L * t), copysignl(t, b));
+ }
+ /* Rescale. */
+ if (scale)
+ return (result * 2.0L);
+ else
+ return (result);
+}