summaryrefslogtreecommitdiffstats
path: root/modules/fdlibm/src/e_log10f.cpp
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /modules/fdlibm/src/e_log10f.cpp
parentInitial commit. (diff)
downloadfirefox-upstream/124.0.1.tar.xz
firefox-upstream/124.0.1.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--modules/fdlibm/src/e_log10f.cpp72
1 files changed, 72 insertions, 0 deletions
diff --git a/modules/fdlibm/src/e_log10f.cpp b/modules/fdlibm/src/e_log10f.cpp
new file mode 100644
index 0000000000..cf3ccd5445
--- /dev/null
+++ b/modules/fdlibm/src/e_log10f.cpp
@@ -0,0 +1,72 @@
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+//#include <sys/cdefs.h>
+//__FBSDID("$FreeBSD$");
+
+/*
+ * Float version of e_log10.c. See the latter for most comments.
+ */
+
+#include "math.h"
+#include "math_private.h"
+#include "k_logf.h"
+
+static const float
+two25 = 3.3554432000e+07, /* 0x4c000000 */
+ivln10hi = 4.3432617188e-01, /* 0x3ede6000 */
+ivln10lo = -3.1689971365e-05, /* 0xb804ead9 */
+log10_2hi = 3.0102920532e-01, /* 0x3e9a2080 */
+log10_2lo = 7.9034151668e-07; /* 0x355427db */
+
+static const float zero = 0.0;
+static volatile float vzero = 0.0;
+
+float
+__ieee754_log10f(float x)
+{
+ float f,hfsq,hi,lo,r,y;
+ int32_t i,k,hx;
+
+ GET_FLOAT_WORD(hx,x);
+
+ k=0;
+ if (hx < 0x00800000) { /* x < 2**-126 */
+ if ((hx&0x7fffffff)==0)
+ return -two25/vzero; /* log(+-0)=-inf */
+ if (hx<0) return (x-x)/zero; /* log(-#) = NaN */
+ k -= 25; x *= two25; /* subnormal number, scale up x */
+ GET_FLOAT_WORD(hx,x);
+ }
+ if (hx >= 0x7f800000) return x+x;
+ if (hx == 0x3f800000)
+ return zero; /* log(1) = +0 */
+ k += (hx>>23)-127;
+ hx &= 0x007fffff;
+ i = (hx+(0x4afb0d))&0x800000;
+ SET_FLOAT_WORD(x,hx|(i^0x3f800000)); /* normalize x or x/2 */
+ k += (i>>23);
+ y = (float)k;
+ f = x - (float)1.0;
+ hfsq = (float)0.5*f*f;
+ r = k_log1pf(f);
+
+ /* See e_log2f.c and e_log2.c for details. */
+ if (sizeof(float_t) > sizeof(float))
+ return (r - hfsq + f) * ((float_t)ivln10lo + ivln10hi) +
+ y * ((float_t)log10_2lo + log10_2hi);
+ hi = f - hfsq;
+ GET_FLOAT_WORD(hx,hi);
+ SET_FLOAT_WORD(hi,hx&0xfffff000);
+ lo = (f - hi) - hfsq + r;
+ return y*log10_2lo + (lo+hi)*ivln10lo + lo*ivln10hi + hi*ivln10hi +
+ y*log10_2hi;
+}