diff --git a/lib/msun/Makefile b/lib/msun/Makefile
index 6ad0e0e5c428..8852439d5b3c 100644
--- a/lib/msun/Makefile
+++ b/lib/msun/Makefile
@@ -1,249 +1,259 @@
 #  @(#)Makefile 5.1beta 93/09/24
 # $FreeBSD$
 #
 #  ====================================================
 #  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.
 #  ====================================================
 #
 #
 
 PACKAGE=	clibs
 ARCH_SUBDIR=	${MACHINE_CPUARCH:S/i386/i387/}
 
 .include "${ARCH_SUBDIR}/Makefile.inc"
 
 .PATH:	${.CURDIR}/${ARCH_SUBDIR}
 .if ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "amd64"
 .PATH:	${.CURDIR}/x86
 CFLAGS+=	-I${.CURDIR}/x86
 .endif
 
 # long double format
 .if ${LDBL_PREC} == 64
 .PATH:  ${.CURDIR}/ld80
 CFLAGS+=	-I${.CURDIR}/ld80
 .elif ${LDBL_PREC} == 113
 .PATH:  ${.CURDIR}/ld128
 CFLAGS+=	-I${.CURDIR}/ld128
 .endif
 
 CFLAGS+=	-I${.CURDIR}/${ARCH_SUBDIR}
 
+.include <bsd.compiler.mk>
+.if ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 100000 && \
+    (${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386")
+# When using clang with x86_64 CPUs that support AVX, some floating point
+# transformations may raise exceptions that would not have been raised by the
+# original code. To avoid this, use the -fp-exception-behavior=maytrap flag,
+# introduced in clang 10.0.0.
+# See also: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254911
+CFLAGS+=	-ffp-exception-behavior=maytrap
+.endif
+
 .PATH:	${.CURDIR}/bsdsrc
 .PATH:	${.CURDIR}/src
 .PATH:	${.CURDIR}/man
 
 LIB=	m
 SHLIBDIR?= /lib
 SHLIB_MAJOR= 5
 WARNS?=	1
 IGNORE_PRAGMA=
 COMMON_SRCS= b_exp.c b_log.c b_tgamma.c \
 	e_acos.c e_acosf.c e_acosh.c e_acoshf.c e_asin.c e_asinf.c \
 	e_atan2.c e_atan2f.c e_atanh.c e_atanhf.c e_cosh.c e_coshf.c e_exp.c \
 	e_expf.c e_fmod.c e_fmodf.c e_gamma.c e_gamma_r.c e_gammaf.c \
 	e_gammaf_r.c e_hypot.c e_hypotf.c e_j0.c e_j0f.c e_j1.c e_j1f.c \
 	e_jn.c e_jnf.c e_lgamma.c e_lgamma_r.c e_lgammaf.c e_lgammaf_r.c \
 	e_log.c e_log10.c e_log10f.c e_log2.c e_log2f.c e_logf.c \
 	e_pow.c e_powf.c e_rem_pio2.c \
 	e_rem_pio2f.c e_remainder.c e_remainderf.c e_scalb.c e_scalbf.c \
 	e_sinh.c e_sinhf.c e_sqrt.c e_sqrtf.c fenv.c \
 	imprecise.c \
 	k_cos.c k_cosf.c k_exp.c k_expf.c k_rem_pio2.c k_sin.c k_sinf.c \
 	k_tan.c k_tanf.c \
 	s_asinh.c s_asinhf.c s_atan.c s_atanf.c s_carg.c s_cargf.c s_cargl.c \
 	s_cbrt.c s_cbrtf.c s_ceil.c s_ceilf.c s_clog.c s_clogf.c \
 	s_copysign.c s_copysignf.c s_cos.c s_cosf.c \
 	s_csqrt.c s_csqrtf.c s_erf.c s_erff.c \
 	s_exp2.c s_exp2f.c s_expm1.c s_expm1f.c s_fabsf.c s_fdim.c \
 	s_finite.c s_finitef.c \
 	s_floor.c s_floorf.c s_fma.c s_fmaf.c \
 	s_fmax.c s_fmaxf.c s_fmin.c \
 	s_fminf.c s_frexp.c s_frexpf.c s_ilogb.c s_ilogbf.c \
 	s_ilogbl.c s_isfinite.c s_isnan.c s_isnormal.c \
 	s_llrint.c s_llrintf.c s_llround.c s_llroundf.c s_llroundl.c \
 	s_log1p.c s_log1pf.c s_logb.c s_logbf.c s_lrint.c s_lrintf.c \
 	s_lround.c s_lroundf.c s_lroundl.c s_modff.c \
 	s_nan.c s_nearbyint.c s_nextafter.c s_nextafterf.c \
 	s_nexttowardf.c s_remquo.c s_remquof.c \
 	s_rint.c s_rintf.c s_round.c s_roundf.c \
 	s_scalbln.c s_scalbn.c s_scalbnf.c s_signbit.c \
 	s_signgam.c s_significand.c s_significandf.c s_sin.c \
 	s_sincos.c s_sincosf.c s_sinf.c \
 	s_tan.c s_tanf.c s_tanh.c s_tanhf.c s_tgammaf.c s_trunc.c s_truncf.c \
 	w_cabs.c w_cabsf.c w_drem.c w_dremf.c
 
 # Location of fpmath.h and _fpmath.h
 .if exists(${LIBCSRCDIR}/${MACHINE_ARCH})
 LIBC_ARCH=${MACHINE_ARCH}
 .else
 LIBC_ARCH=${MACHINE_CPUARCH}
 .endif
 CFLAGS+=	-I${.CURDIR}/src -I${LIBCSRCDIR}/include \
 	-I${LIBCSRCDIR}/${LIBC_ARCH}
 SYM_MAPS+=	${.CURDIR}/Symbol.map
 
 VERSION_DEF=	${LIBCSRCDIR}/Versions.def
 SYMBOL_MAPS=	${SYM_MAPS}
 
 # C99 long double functions
 COMMON_SRCS+=	s_copysignl.c s_fabsl.c s_llrintl.c s_lrintl.c s_modfl.c
 .if ${LDBL_PREC} != 53
 # If long double != double use these; otherwise, we alias the double versions.
 COMMON_SRCS+=	catrigl.c \
 	e_acoshl.c e_acosl.c e_asinl.c e_atan2l.c e_atanhl.c \
 	e_coshl.c e_fmodl.c e_hypotl.c \
 	e_lgammal.c e_lgammal_r.c e_powl.c \
 	e_remainderl.c e_sinhl.c e_sqrtl.c \
 	invtrig.c k_cosl.c k_sinl.c k_tanl.c \
 	s_asinhl.c s_atanl.c s_cbrtl.c s_ceill.c \
 	s_clogl.c s_cosl.c s_cprojl.c \
 	s_csqrtl.c s_erfl.c s_exp2l.c s_expl.c s_floorl.c s_fmal.c \
 	s_fmaxl.c s_fminl.c s_frexpl.c s_logbl.c s_logl.c s_nanl.c \
 	s_nextafterl.c s_nexttoward.c s_remquol.c s_rintl.c s_roundl.c \
 	s_scalbnl.c s_sinl.c s_sincosl.c \
 	s_tanhl.c s_tanl.c s_truncl.c w_cabsl.c
 # Work around this warning from gcc 6:
 #     lib/msun/ld80/e_powl.c:275:1: error: floating constant exceeds range of
 #     'long double' [-Werror=overflow]
 #     if( y >= LDBL_MAX )
 # See also: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=130067
-.include <bsd.compiler.mk>
 .if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} >= 60000
 CFLAGS.e_powl.c+= -Wno-error=overflow
 .endif
 .endif
 
 # C99 complex functions
 COMMON_SRCS+=	catrig.c catrigf.c \
 	s_ccosh.c s_ccoshf.c s_cexp.c s_cexpf.c \
 	s_cimag.c s_cimagf.c s_cimagl.c \
 	s_conj.c s_conjf.c s_conjl.c \
 	s_cpow.c s_cpowf.c s_cpowl.c \
 	s_cproj.c s_cprojf.c s_creal.c s_crealf.c s_creall.c \
 	s_csinh.c s_csinhf.c s_ctanh.c s_ctanhf.c
 
 # FreeBSD's C library supplies these functions:
 #COMMON_SRCS+=	s_fabs.c s_frexp.c s_isnan.c s_ldexp.c s_modf.c
 
 # Exclude the generic versions of what we provide in the MD area.
 .if defined(ARCH_SRCS)
 .for i in ${ARCH_SRCS}
 COMMON_SRCS:=  ${COMMON_SRCS:N${i:R}.c}
 .endfor
 .endif
 
 SRCS=	${COMMON_SRCS} ${ARCH_SRCS}
 
 INCS+=	fenv.h math.h
 
 MAN=	acos.3 acosh.3 asin.3 asinh.3 atan.3 atan2.3 atanh.3 \
 	ceil.3 cacos.3 ccos.3 ccosh.3 cexp.3 \
 	cimag.3 clog.3 copysign.3 cos.3 cosh.3 cpow.3 csqrt.3 erf.3 \
 	exp.3 fabs.3 fdim.3 \
 	feclearexcept.3 feenableexcept.3 fegetenv.3 \
 	fegetround.3 fenv.3 floor.3 \
 	fma.3 fmax.3 fmod.3 hypot.3 ieee.3 ieee_test.3 ilogb.3 j0.3 \
 	lgamma.3 log.3 lrint.3 lround.3 math.3 nan.3 \
 	nextafter.3 remainder.3 rint.3 \
 	round.3 scalbn.3 signbit.3 sin.3 sincos.3 \
 	sinh.3 sqrt.3 tan.3 tanh.3 trunc.3 \
 	complex.3
 
 MLINKS+=acos.3 acosf.3 acos.3 acosl.3
 MLINKS+=acosh.3 acoshf.3 acosh.3 acoshl.3
 MLINKS+=asin.3 asinf.3 asin.3 asinl.3
 MLINKS+=asinh.3 asinhf.3 asinh.3 asinhl.3
 MLINKS+=atan.3 atanf.3 atan.3 atanl.3
 MLINKS+=atanh.3 atanhf.3 atanh.3 atanhl.3
 MLINKS+=atan2.3 atan2f.3 atan2.3 atan2l.3 \
 	atan2.3 carg.3 atan2.3 cargf.3 atan2.3 cargl.3
 MLINKS+=cacos.3 cacosf.3 cacos.3 cacosl.3 \
 	cacos.3 cacosh.3 cacos.3 cacoshf.3 cacos.3 cacoshl.3 \
 	cacos.3 casin.3 cacos.3 casinf.3 cacos.3 casinl.3 \
 	cacos.3 casinh.3 cacos.3 casinhf.3 cacos.3 casinhl.3 \
 	cacos.3 catan.3 cacos.3 catanf.3 cacos.3 catanl.3 \
 	cacos.3 catanh.3 cacos.3 catanhf.3 cacos.3 catanhl.3
 MLINKS+=ccos.3 ccosf.3 ccos.3 csin.3 ccos.3 csinf.3 ccos.3 ctan.3 ccos.3 ctanf.3
 MLINKS+=ccosh.3 ccoshf.3 ccosh.3 csinh.3 ccosh.3 csinhf.3 \
 	ccosh.3 ctanh.3 ccosh.3 ctanhf.3
 MLINKS+=ceil.3 ceilf.3 ceil.3 ceill.3
 MLINKS+=cexp.3 cexpf.3
 MLINKS+=cimag.3 cimagf.3 cimag.3 cimagl.3 \
 	cimag.3 conj.3 cimag.3 conjf.3 cimag.3 conjl.3 \
 	cimag.3 cproj.3 cimag.3 cprojf.3 cimag.3 cprojl.3 \
 	cimag.3 creal.3 cimag.3 crealf.3 cimag.3 creall.3
 MLINKS+=clog.3 clogf.3 clog.3 clogl.3
 MLINKS+=copysign.3 copysignf.3 copysign.3 copysignl.3
 MLINKS+=cos.3 cosf.3 cos.3 cosl.3
 MLINKS+=cosh.3 coshf.3 cosh.3 coshl.3
 MLINKS+=cpow.3 cpowf.3 cpow.3 cpowl.3
 MLINKS+=csqrt.3 csqrtf.3 csqrt.3 csqrtl.3
 MLINKS+=erf.3 erfc.3 erf.3 erff.3 erf.3 erfcf.3 erf.3 erfl.3 erf.3 erfcl.3
 MLINKS+=exp.3 expm1.3 exp.3 expm1f.3 exp.3 expm1l.3 exp.3 pow.3 exp.3 powf.3 \
 	exp.3 powl.3 exp.3 exp2.3 exp.3 exp2f.3 exp.3 exp2l.3 exp.3 expf.3 \
 	exp.3 expl.3
 MLINKS+=fabs.3 fabsf.3 fabs.3 fabsl.3
 MLINKS+=fdim.3 fdimf.3 fdim.3 fdiml.3
 MLINKS+=feclearexcept.3 fegetexceptflag.3 feclearexcept.3 feraiseexcept.3 \
 	feclearexcept.3 fesetexceptflag.3 feclearexcept.3 fetestexcept.3
 MLINKS+=feenableexcept.3 fedisableexcept.3 feenableexcept.3 fegetexcept.3
 MLINKS+=fegetenv.3 feholdexcept.3 fegetenv.3 fesetenv.3 \
 	fegetenv.3 feupdateenv.3
 MLINKS+=fegetround.3 fesetround.3
 MLINKS+=floor.3 floorf.3 floor.3 floorl.3
 MLINKS+=fma.3 fmaf.3 fma.3 fmal.3
 MLINKS+=fmax.3 fmaxf.3 fmax.3 fmaxl.3 \
 	fmax.3 fmin.3 fmax.3 fminf.3 fmax.3 fminl.3
 MLINKS+=fmod.3 fmodf.3 fmod.3 fmodl.3
 MLINKS+=hypot.3 cabs.3 hypot.3 cabsf.3 hypot.3 cabsl.3 \
 	hypot.3 hypotf.3 hypot.3 hypotl.3
 MLINKS+=ieee_test.3 scalb.3 ieee_test.3 scalbf.3
 MLINKS+=ieee_test.3 significand.3 ieee_test.3 significandf.3
 MLINKS+=ilogb.3 ilogbf.3 ilogb.3 ilogbl.3 \
 	ilogb.3 logb.3 ilogb.3 logbf.3 ilogb.3 logbl.3
 MLINKS+=j0.3 j1.3 j0.3 jn.3 j0.3 y0.3 j0.3 y1.3 j0.3 y1f.3 j0.3 yn.3
 MLINKS+=j0.3 j0f.3 j0.3 j1f.3 j0.3 jnf.3 j0.3 y0f.3 j0.3 ynf.3
 MLINKS+=lgamma.3 gamma.3 lgamma.3 gammaf.3 \
 	lgamma.3 lgammaf.3 lgamma.3 lgammal.3 \
 	lgamma.3 tgamma.3 lgamma.3 tgammaf.3
 MLINKS+=log.3 log10.3 log.3 log10f.3 log.3 log10l.3 \
 	log.3 log1p.3 log.3 log1pf.3 log.3 log1pl.3 \
 	log.3 logf.3 log.3 logl.3 \
 	log.3 log2.3 log.3 log2f.3 log.3 log2l.3
 MLINKS+=lrint.3 llrint.3 lrint.3 llrintf.3 lrint.3 llrintl.3 \
 	lrint.3 lrintf.3 lrint.3 lrintl.3
 MLINKS+=lround.3 llround.3 lround.3 llroundf.3 lround.3 llroundl.3 \
 	lround.3 lroundf.3 lround.3 lroundl.3
 MLINKS+=nan.3 nanf.3 nan.3 nanl.3
 MLINKS+=nextafter.3 nextafterf.3 nextafter.3 nextafterl.3
 MLINKS+=nextafter.3 nexttoward.3 nextafter.3 nexttowardf.3
 MLINKS+=nextafter.3 nexttowardl.3
 MLINKS+=remainder.3 remainderf.3 remainder.3 remainderl.3 \
 	remainder.3 remquo.3 remainder.3 remquof.3 remainder.3 remquol.3
 MLINKS+=rint.3 rintf.3 rint.3 rintl.3 \
 	rint.3 nearbyint.3 rint.3 nearbyintf.3 rint.3 nearbyintl.3
 MLINKS+=round.3 roundf.3 round.3 roundl.3
 MLINKS+=scalbn.3 scalbln.3 scalbn.3 scalblnf.3 scalbn.3 scalblnl.3
 MLINKS+=scalbn.3 scalbnf.3 scalbn.3 scalbnl.3
 MLINKS+=sin.3 sinf.3 sin.3 sinl.3
 MLINKS+=sincos.3 sincosf.3 sin.3 sincosl.3
 MLINKS+=sinh.3 sinhf.3 sinh.3 sinhl.3
 MLINKS+=sqrt.3 cbrt.3 sqrt.3 cbrtf.3 sqrt.3 cbrtl.3 sqrt.3 sqrtf.3 \
 	sqrt.3 sqrtl.3
 MLINKS+=tan.3 tanf.3 tan.3 tanl.3
 MLINKS+=tanh.3 tanhf.3 tanh.3 tanhl.3
 MLINKS+=trunc.3 truncf.3 trunc.3 truncl.3
 
 .include <src.opts.mk>
 
 .if ${MK_TESTS} != "no"
 SUBDIR+=	tests
 .endif
 
 .include <bsd.lib.mk>