intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 96 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Python/pymath.c b/contrib/tools/python3/src/Python/pymath.c
new file mode 100644
index 0000000000..a08a0e7961
--- /dev/null
+++ b/contrib/tools/python3/src/Python/pymath.c
@@ -0,0 +1,96 @@
+#include "Python.h"
+
+#ifdef X87_DOUBLE_ROUNDING
+/* On x86 platforms using an x87 FPU, this function is called from the
+   Py_FORCE_DOUBLE macro (defined in pymath.h) to force a floating-point
+   number out of an 80-bit x87 FPU register and into a 64-bit memory location,
+   thus rounding from extended precision to double precision. */
+double _Py_force_double(double x)
+{
+    volatile double y;
+    y = x;
+    return y;
+}
+#endif
+
+#ifdef HAVE_GCC_ASM_FOR_X87
+
+/* inline assembly for getting and setting the 387 FPU control word on
+   gcc/x86 */
+#ifdef _Py_MEMORY_SANITIZER
+__attribute__((no_sanitize_memory))
+#endif
+unsigned short _Py_get_387controlword(void) {
+    unsigned short cw;
+    __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
+    return cw;
+}
+
+void _Py_set_387controlword(unsigned short cw) {
+    __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
+}
+
+#endif
+
+
+#ifndef HAVE_HYPOT
+double hypot(double x, double y)
+{
+    double yx;
+
+    x = fabs(x);
+    y = fabs(y);
+    if (x < y) {
+        double temp = x;
+        x = y;
+        y = temp;
+    }
+    if (x == 0.)
+        return 0.;
+    else {
+        yx = y/x;
+        return x*sqrt(1.+yx*yx);
+    }
+}
+#endif /* HAVE_HYPOT */
+
+#ifndef HAVE_COPYSIGN
+double
+copysign(double x, double y)
+{
+    /* use atan2 to distinguish -0. from 0. */
+    if (y > 0. || (y == 0. && atan2(y, -1.) > 0.)) {
+        return fabs(x);
+    } else {
+        return -fabs(x);
+    }
+}
+#endif /* HAVE_COPYSIGN */
+
+#ifndef HAVE_ROUND
+double
+round(double x)
+{
+    double absx, y;
+    absx = fabs(x);
+    y = floor(absx);
+    if (absx - y >= 0.5)
+        y += 1.0;
+    return copysign(y, x);
+}
+#endif /* HAVE_ROUND */
+
+static const unsigned int BitLengthTable[32] = {
+    0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
+};
+
+unsigned int _Py_bit_length(unsigned long d) {
+   unsigned int d_bits = 0;
+   while (d >= 32) {
+       d_bits += 6;
+       d >>= 6;
+   }
+   d_bits += BitLengthTable[d];
+   return d_bits;
+}