Switch to FreeBSD's actual sincos.

Before:
  BM_math_sin_fast                48 ns         48 ns   14693053
  BM_math_sincos                  61 ns         61 ns   11470219

After:
  BM_math_sin_fast                48 ns         48 ns   14725120
  BM_math_sincos                  43 ns         43 ns   16329843

Bug: N/A
Test: ran tests, benchmarks
Change-Id: I8693c64135233c0641af5302c38748f47ac76737
diff --git a/libm/upstream-freebsd/lib/msun/src/s_sincosf.c b/libm/upstream-freebsd/lib/msun/src/s_sincosf.c
new file mode 100644
index 0000000..4aaa780
--- /dev/null
+++ b/libm/upstream-freebsd/lib/msun/src/s_sincosf.c
@@ -0,0 +1,126 @@
+/*-
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/* s_sincosf.c -- float version of s_sincos.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ * Optimized by Bruce D. Evans.
+ * Merged s_sinf.c and s_cosf.c by Steven G. Kargl.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: head/lib/msun/src/s_sincosf.c 319047 2017-05-28 06:13:38Z mmel $");
+
+#include <float.h>
+
+#include "math.h"
+#define INLINE_REM_PIO2F
+#include "math_private.h"
+#include "e_rem_pio2f.c"
+#include "k_sincosf.h"
+
+/* Small multiples of pi/2 rounded to double precision. */
+static const double
+p1pio2 = 1*M_PI_2,			/* 0x3FF921FB, 0x54442D18 */
+p2pio2 = 2*M_PI_2,			/* 0x400921FB, 0x54442D18 */
+p3pio2 = 3*M_PI_2,			/* 0x4012D97C, 0x7F3321D2 */
+p4pio2 = 4*M_PI_2;			/* 0x401921FB, 0x54442D18 */
+
+void
+sincosf(float x, float *sn, float *cs)
+{
+	float c, s;
+	double y;
+	int32_t n, hx, ix;
+
+	GET_FLOAT_WORD(hx, x);
+	ix = hx & 0x7fffffff;
+
+	if (ix <= 0x3f490fda) {		/* |x| ~<= pi/4 */
+		if (ix < 0x39800000) {	/* |x| < 2**-12 */
+			if ((int)x == 0) {
+				*sn = x;	/* x with inexact if x != 0 */
+				*cs = 1;
+				return;
+			}
+		}
+		__kernel_sincosdf(x, sn, cs);
+		return;
+	}
+
+	if (ix <= 0x407b53d1) {		/* |x| ~<= 5*pi/4 */
+		if (ix <= 0x4016cbe3) {	/* |x| ~<= 3pi/4 */
+			if (hx > 0) {
+				__kernel_sincosdf(x - p1pio2, cs, sn);
+				*cs = -*cs;
+			} else {
+				__kernel_sincosdf(x + p1pio2, cs, sn);
+				*sn = -*sn;
+			}
+		} else {
+			if (hx > 0)
+				__kernel_sincosdf(x - p2pio2, sn, cs);
+			else
+				__kernel_sincosdf(x + p2pio2, sn, cs);
+			*sn = -*sn;
+			*cs = -*cs;
+		}
+		return;
+	}
+
+	if (ix <= 0x40e231d5) {		/* |x| ~<= 9*pi/4 */
+		if (ix <= 0x40afeddf) {	/* |x| ~<= 7*pi/4 */
+			if (hx > 0) {
+				__kernel_sincosdf(x - p3pio2, cs, sn);
+				*sn = -*sn;
+			} else {
+				__kernel_sincosdf(x + p3pio2, cs, sn);
+				*cs = -*cs;
+			}
+		} else {
+			if (hx > 0)
+				__kernel_sincosdf(x - p4pio2, sn, cs);
+			else
+				__kernel_sincosdf(x + p4pio2, sn, cs);
+		}
+		return;
+	}
+
+	/* If x = Inf or NaN, then sin(x) = NaN and cos(x) = NaN. */
+	if (ix >= 0x7f800000) {
+		*sn = x - x;
+		*cs = x - x;
+		return;
+	}
+
+	/* Argument reduction. */
+	n = __ieee754_rem_pio2f(x, &y);
+	__kernel_sincosdf(y, &s, &c);
+
+	switch(n & 3) {
+	case 0:
+		*sn = s;
+		*cs = c;
+		break;
+	case 1:
+		*sn = c;
+		*cs = -s;
+		break;
+	case 2:
+		*sn = -s;
+		*cs = -c;
+		break;
+	default:
+		*sn = -c;
+		*cs = s;
+	}
+}
+
+