diff --git a/lib/msun/ld128/s_cospil.c b/lib/msun/ld128/s_cospil.c
index b4bc50bb4d89..71acc4485f7b 100644
--- a/lib/msun/ld128/s_cospil.c
+++ b/lib/msun/ld128/s_cospil.c
@@ -1,109 +1,112 @@
 /*-
- * Copyright (c) 2017 Steven G. Kargl
+ * Copyright (c) 2017-2021 Steven G. Kargl
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice unmodified, this list of conditions, and the following
  *    disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /*
  * See ../src/s_cospi.c for implementation details.
- *
- * FIXME:  This has not been compiled nor has it been tested for accuracy.
- * FIXME:  This should use bit twiddling.
  */
 
 #include "math.h"
 #include "math_private.h"
 
 /*
  * pi_hi contains the leading 56 bits of a 169 bit approximation for pi.
  */
 static const long double
 pi_hi = 3.14159265358979322702026593105983920e+00L,
 pi_lo = 1.14423774522196636802434264184180742e-17L;
 
 #include "k_cospil.h"
 #include "k_sinpil.h"
 
 volatile static const double vzero = 0;
 
 long double
 cospil(long double x)
 {
 	long double ax, c, xf;
 	uint32_t ix;
 
 	ax = fabsl(x);
 
-	if (ax < 1) {
+	if (ax <= 1) {
 		if (ax < 0.25) {
 			if (ax < 0x1p-60) {
 				if ((int)x == 0)
 					return (1);
 			}
 			return (__kernel_cospil(ax));
 		}
 
 		if (ax < 0.5)
 			c = __kernel_sinpil(0.5 - ax);
 		else if (ax < 0.75) {
 			if (ax == 0.5)
 				return (0);
 			c = -__kernel_sinpil(ax - 0.5);
 		} else
 			c = -__kernel_cospil(1 - ax);
 		return (c);
 	}
 
 	if (ax < 0x1p112) {
-		xf = floorl(ax);
-		ax -= xf;
-		if (x < 0.5) {
-			if (x < 0.25)
+		/* Split x = n + r with 0 <= r < 1. */
+		xf = (ax + 0x1p112L) - 0x1p112L;        /* Integer part */
+		ax -= xf;                               /* Remainder */
+		if (ax < 0) {
+			ax += 1;
+			xf -= 1;
+		}
+
+		if (ax < 0.5) {
+			if (ax < 0.25)
 				c = ax == 0 ? 1 : __kernel_cospil(ax);
 			else
 				c = __kernel_sinpil(0.5 - ax);
 		} else {
-			if (x < 0.75) {
+			if (ax < 0.75) {
 				if (ax == 0.5)
 					return (0);
 				c = -__kernel_sinpil(ax - 0.5);
 			} else
 				c = -__kernel_cospil(1 - ax);
 		}
 
-		if (xf > 0x1p50)
-			xf -= 0x1p50;
-		if (xf > 0x1p30)
-			xf -= 0x1p30;
+		if (xf > 0x1p64)
+			xf -= 0x1p64;
+		if (xf > 0x1p32)
+			xf -= 0x1p32;
 		ix = (uint32_t)xf;
 		return (ix & 1 ? -c : c);
 	}
 
 	if (isinf(x) || isnan(x))
 		return (vzero / vzero);
 
 	/*
 	 * |x| >= 0x1p112 is always an even integer, so return 1.
 	 */
 	return (1);
 }
diff --git a/lib/msun/ld128/s_sinpil.c b/lib/msun/ld128/s_sinpil.c
index 39eed9b007bc..cdfa2bcac3ef 100644
--- a/lib/msun/ld128/s_sinpil.c
+++ b/lib/msun/ld128/s_sinpil.c
@@ -1,118 +1,121 @@
 /*-
- * Copyright (c) 2017 Steven G. Kargl
+ * Copyright (c) 2017-2021 Steven G. Kargl
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice unmodified, this list of conditions, and the following
  *    disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /*
  * See ../src/s_sinpi.c for implementation details.
- *
- * FIXME:  This has not been compiled nor has it been tested for accuracy.
- * FIXME:  This should use bit twiddling.
  */
 
 #include "math.h"
 #include "math_private.h"
 
 /*
  * pi_hi contains the leading 56 bits of a 169 bit approximation for pi.
  */
 static const long double
 pi_hi = 3.14159265358979322702026593105983920e+00L,
 pi_lo = 1.14423774522196636802434264184180742e-17L;
 
 #include "k_cospil.h"
 #include "k_sinpil.h"
 
 volatile static const double vzero = 0;
 
 long double
 sinpil(long double x)
 {
 	long double ax, hi, lo, s, xf, xhi, xlo;
 	uint32_t ix;
 
 	ax = fabsl(x);
 
 	if (ax < 1) {
 		if (ax < 0.25) {
 			if (ax < 0x1p-60) {
 				if (x == 0)
 					return (x);
 				hi = (double)x;
 				hi *= 0x1p113L;
 				lo = x * 0x1p113L - hi;
 				s = (pi_lo + pi_hi) * lo + pi_lo * lo +
 				    pi_hi * hi;
 				return (s * 0x1p-113L);
 			}
 
 			s = __kernel_sinpil(ax);
-			return (copysignl(s, x));
+			return (x < 0 ? -s : s);
 		}
 
 		if (ax < 0.5)
 			s = __kernel_cospil(0.5 - ax);
 		else if (ax < 0.75)
 			s = __kernel_cospil(ax - 0.5);
 		else
 			s = __kernel_sinpil(1 - ax);
-		return (copysignl(s, x));
+		return (x < 0 ? -s : s);
 	}
 
 	if (ax < 0x1p112) {
-		xf = floorl(ax);
-		ax -= xf;
+		/* Split x = n + r with 0 <= r < 1. */
+		xf = (ax + 0x1p112L) - 0x1p112L;        /* Integer part */
+		ax -= xf;                               /* Remainder */
+		if (ax < 0) {
+			ax += 1;
+			xf -= 1;
+		}
+
 		if (ax == 0) {
 			s = 0;
 		} else {
 			if (ax < 0.5) {
 				if (ax <= 0.25)
 					s = __kernel_sinpil(ax);
 				else
 					s = __kernel_cospil(0.5 - ax);
 			} else {
 				if (ax < 0.75)
 					s = __kernel_cospil(ax - 0.5);
 				else
 					s = __kernel_sinpil(1 - ax);
 			}
 
-			if (xf > 0x1p50)
-				xf -= 0x1p50;
-			if (xf > 0x1p30)
-				xf -= 0x1p30;
+			if (xf > 0x1p64)
+				xf -= 0x1p64;
+			if (xf > 0x1p32)
+				xf -= 0x1p32;
 			ix = (uint32_t)xf;
 			if (ix & 1) s = -s;
 		}
-		return (copysignl(s, x));
+		return (x < 0 ? -s : s);
 	}
 
 	if (isinf(x) || isnan(x))
 		return (vzero / vzero);
 
 	/*
 	 * |x| >= 0x1p112 is always an integer, so return +-0.
 	 */
 	return (copysignl(0, x));
 }
diff --git a/lib/msun/ld128/s_tanpil.c b/lib/msun/ld128/s_tanpil.c
index 7cbbdc8a5d05..90f4aea5c629 100644
--- a/lib/msun/ld128/s_tanpil.c
+++ b/lib/msun/ld128/s_tanpil.c
@@ -1,120 +1,123 @@
 /*-
- * Copyright (c) 2017 Steven G. Kargl
+ * Copyright (c) 2017-2021 Steven G. Kargl
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice unmodified, this list of conditions, and the following
  *    disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /*
  * See ../src/s_tanpi.c for implementation details.
- *
- * FIXME: This has not been compiled nor has it been tested for accuracy.
- * FIXME: This should use bit twiddling.
  */
 
 #include "math.h"
 #include "math_private.h"
 
 /*
  * pi_hi contains the leading 56 bits of a 169 bit approximation for pi.
  */
 static const long double
 pi_hi = 3.14159265358979322702026593105983920e+00L,
 pi_lo = 1.14423774522196636802434264184180742e-17L;
 
 static inline long double
 __kernel_tanpil(long double x)
 {
 	long double hi, lo, t;
 
 	if (x < 0.25) {
 		hi = (double)x;
 		lo = x - hi;
 		lo = lo * (pi_lo + pi_hi) + hi * pi_lo;
 		hi *= pi_hi;
 		_2sumF(hi, lo);
 		t = __kernel_tanl(hi, lo, -1);
 	} else if (x > 0.25) {
 		x = 0.5 - x;
 		hi = (double)x;
 		lo = x - hi;
 		lo = lo * (pi_lo + pi_hi) + hi * pi_lo;
 		hi *= pi_hi;
 		_2sumF(hi, lo);
 		t = - __kernel_tanl(hi, lo, 1);
 	} else
 		t = 1;
 
 	return (t);
 }
 
 volatile static const double vzero = 0;
 
 long double
 tanpil(long double x)
 {
 	long double ax, hi, lo, xf, t;
 	uint32_t ix;
 
-	ax = fabsl(ax);
+	ax = fabsl(x);
 
 	if (ax < 1) {
 		if (ax < 0.5) {
 			if (ax < 0x1p-60) {
 				if (x == 0)
 					return (x);
 				hi = (double)x;
 				hi *= 0x1p113L;
 				lo = x * 0x1p113L - hi;
 				t = (pi_lo + pi_hi) * lo + pi_lo * lo +
 				    pi_hi * hi;
 				return (t * 0x1p-113L);
 			}
 			t = __kernel_tanpil(ax);
 		} else if (ax == 0.5)
 			return ((ax - ax) / (ax - ax));
 		else
 			t = -__kernel_tanpil(1 - ax);
-		return (copysignl(t, x));
+		return (x < 0 ? -t : t);
 	}
 
 	if (ix < 0x1p112) {
-		xf = floorl(ax);
-		ax -= xf;
+		/* Split x = n + r with 0 <= r < 1. */
+		xf = (ax + 0x1p112L) - 0x1p112L;        /* Integer part */
+		ax -= xf;                               /* Remainder */
+		if (ax < 0) {
+			ax += 1;
+			xf -= 1;
+		}
+
 		if (ax < 0.5)
 			t = ax == 0 ? 0 : __kernel_tanpil(ax);
 		else if (ax == 0.5)
 			return ((ax - ax) / (ax - ax));
 		else
 			t = -__kernel_tanpil(1 - ax);
-		return (copysignl(t, x));
+		return (x < 0 ? -t : t);
 	}
 
 	/* x = +-inf or nan. */
 	if (isinf(x) || isnan(x))
 		return (vzero / vzero);
 
 	/*
-	 * |x| >= 0x1p53 is always an integer, so return +-0.
+	 * |x| >= 0x1p112 is always an integer, so return +-0.
 	 */
 	return (copysignl(0, x));
 }