[LIBM] Import win-libm from AMD

Source: https://github.com/amd/win-libm
2025-08-03 13:35:47 +00:00 · 2022-06-12 12:02:01 +02:00 · 2022-06-12 12:02:01 +02:00 · 4afb647c78
commit 4afb647c78
parent 081c637c06
82 changed files with 22392 additions and 0 deletions
--- a/sdk/lib/crt/math/libm_sse2/atanf.c
+++ b/sdk/lib/crt/math/libm_sse2/atanf.c
@ -0,0 +1,135 @@
+
+/*******************************************************************************
+MIT License
+-----------
+
+Copyright (c) 2002-2019 Advanced Micro Devices, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this Software and associated documentaon files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*******************************************************************************/
+
+#include "libm.h"
+#include "libm_util.h"
+
+#define USE_VALF_WITH_FLAGS
+#define USE_NAN_WITH_FLAGS
+#define USE_HANDLE_ERRORF
+#include "libm_inlines.h"
+#undef USE_VALF_WITH_FLAGS
+#undef USE_NAN_WITH_FLAGS
+#undef USE_HANDLE_ERRORF
+
+#include "libm_errno.h"
+
+// Disable "C4163: not available as intrinsic function" warning that older
+// compilers may issue here.
+#pragma warning(disable:4163)
+#pragma function(atanf)
+
+float FN_PROTOTYPE(atanf)(float fx)
+{
+
+  /* Some constants and split constants. */
+
+  static double piby2 = 1.5707963267948966e+00; /* 0x3ff921fb54442d18 */
+
+  double c, v, s, q, z;
+  unsigned int xnan;
+
+  double x = fx;
+
+  /* Find properties of argument fx. */
+
+  unsigned long ux, aux, xneg;
+
+  GET_BITS_DP64(x, ux);
+  aux = ux & ~SIGNBIT_DP64;
+  xneg = ux & SIGNBIT_DP64;
+
+  v = x;
+  if (xneg) v = -x;
+
+  /* Argument reduction to range [-7/16,7/16] */
+
+  if (aux < 0x3fdc000000000000) /* v < 7./16. */
+    {
+      x = v;
+      c = 0.0;
+    }
+  else if (aux < 0x3fe6000000000000) /* v < 11./16. */
+    {
+      x = (2.0*v-1.0)/(2.0+v);
+      /* c = arctan(0.5) */
+      c = 4.63647609000806093515e-01; /* 0x3fddac670561bb4f */
+    }
+  else if (aux < 0x3ff3000000000000) /* v < 19./16. */
+    {
+      x = (v-1.0)/(1.0+v);
+      /* c = arctan(1.) */
+      c = 7.85398163397448278999e-01; /* 0x3fe921fb54442d18 */
+    }
+  else if (aux < 0x4003800000000000) /* v < 39./16. */
+    {
+      x = (v-1.5)/(1.0+1.5*v);
+      /* c = arctan(1.5) */
+      c = 9.82793723247329054082e-01; /* 0x3fef730bd281f69b */
+    }
+  else
+    {
+
+      xnan = (aux > PINFBITPATT_DP64);
+
+      if (xnan)
+        {
+          /* x is NaN */
+          unsigned int uhx;
+          GET_BITS_SP32(fx, uhx);
+          return _handle_errorf("atanf", OP_ATAN, uhx|0x00400000, _DOMAIN,
+                               0, EDOM, fx, 0.0F, 1);
+        }
+      else if (v > 0x4c80000000000000)
+	{ /* abs(x) > 2^26 => arctan(1/x) is
+	     insignificant compared to piby2 */
+	  if (xneg)
+            return valf_with_flags((float)-piby2, AMD_F_INEXACT);
+	  else
+            return valf_with_flags((float)piby2, AMD_F_INEXACT);
+	}
+
+      x = -1.0/v;
+      /* c = arctan(infinity) */
+      c = 1.57079632679489655800e+00; /* 0x3ff921fb54442d18 */
+    }
+
+  /* Core approximation: Remez(2,2) on [-7/16,7/16] */
+
+  s = x*x;
+  q = x*s*
+    (0.296528598819239217902158651186e0 +
+     (0.192324546402108583211697690500e0 +
+       0.470677934286149214138357545549e-2*s)*s)/
+    (0.889585796862432286486651434570e0 +
+     (0.111072499995399550138837673349e1 +
+       0.299309699959659728404442796915e0*s)*s);
+
+  z = c - (q - x);
+
+  if (xneg) z = -z;
+  return (float)z;
+}