23 files changed, 248 insertions, 178 deletions

diff --git a/av.h b/av.h
index bef763d3b1..bacf614390 100644
--- a/av.h
+++ b/av.h
@@ -12,7 +12,7 @@ struct xpvav {
     SSize_t	xav_fill;       /* Index of last element present */
     SSize_t	xav_max;        /* Number of elements for which array has space */
     IV		xof_off;	/* ptr is incremented by offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV		xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* magic for scalar array */
     HV*		xmg_stash;	/* class package */
 
diff --git a/bytecode.pl b/bytecode.pl
index 1e18d55990..4d318ff4fa 100644
--- a/bytecode.pl
+++ b/bytecode.pl
@@ -312,7 +312,7 @@ xrv		SvRV(bytecode_sv)			svindex
 xpv		bytecode_sv				none		x
 xiv32		SvIVX(bytecode_sv)			I32
 xiv64		SvIVX(bytecode_sv)			IV64
-xnv		SvNVX(bytecode_sv)			double
+xnv		SvNVX(bytecode_sv)			NV
 xlv_targoff	LvTARGOFF(bytecode_sv)			STRLEN
 xlv_targlen	LvTARGLEN(bytecode_sv)			STRLEN
 xlv_targ	LvTARG(bytecode_sv)			svindex
diff --git a/cv.h b/cv.h
index e060dc8abd..704270871c 100644
--- a/cv.h
+++ b/cv.h
@@ -14,7 +14,7 @@ struct xpvcv {
     STRLEN	xpv_cur;	/* length of xp_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xof_off;	/* integer value */
-    double	xnv_nv;		/* numeric value, if any */
+    NV		xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* magic for scalar array */
     HV*		xmg_stash;	/* class package */
 
diff --git a/doio.c b/doio.c
index 0fc139cbfc..39e2e9f6ac 100644
--- a/doio.c
+++ b/doio.c
@@ -898,7 +898,7 @@ Perl_do_print(pTHX_ register SV *sv, PerlIO *fp)
 	if (SvGMAGICAL(sv))
 	    mg_get(sv);
         if (SvIOK(sv) && SvIVX(sv) != 0) {
-	    PerlIO_printf(fp, PL_ofmt, (double)SvIVX(sv));
+	    PerlIO_printf(fp, PL_ofmt, (NV)SvIVX(sv));
 	    return !PerlIO_error(fp);
 	}
 	if (  (SvNOK(sv) && SvNVX(sv) != 0.0)
diff --git a/dump.c b/dump.c
index 3d3a55c497..9c7d3a9764 100644
--- a/dump.c
+++ b/dump.c
@@ -972,7 +972,7 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 	    int i;
 	    int max = 0;
 	    U32 pow2 = 2, keys = HvKEYS(sv);
-	    double theoret, sum = 0;
+	    NV theoret, sum = 0;
 
 	    PerlIO_printf(file, "  (");
 	    Zero(freq, FREQ_MAX + 1, int);
diff --git a/embed.pl b/embed.pl
index d7c5a87e2d..ad91f80962 100755
--- a/embed.pl
+++ b/embed.pl
@@ -781,10 +781,10 @@ p	|int	|block_start	|int full
 p	|void	|boot_core_UNIVERSAL
 p	|void	|call_list	|I32 oldscope|AV* av_list
 p	|I32	|cando		|I32 bit|I32 effective|Stat_t* statbufp
-p	|U32	|cast_ulong	|double f
-p	|I32	|cast_i32	|double f
-p	|IV	|cast_iv	|double f
-p	|UV	|cast_uv	|double f
+p	|U32	|cast_ulong	|NV f
+p	|I32	|cast_i32	|NV f
+p	|IV	|cast_iv	|NV f
+p	|UV	|cast_uv	|NV f
 #if !defined(HAS_TRUNCATE) && !defined(HAS_CHSIZE) && defined(F_FREESP)
 p	|I32	|my_chsize	|int fd|Off_t length
 #endif
@@ -1058,7 +1058,7 @@ p	|I32	|mg_size	|SV* sv
 p	|OP*	|mod		|OP* o|I32 type
 p	|char*	|moreswitches	|char* s
 p	|OP*	|my		|OP* o
-p	|double	|my_atof	|const char *s
+p	|NV	|my_atof	|const char *s
 #if !defined(HAS_BCOPY) || !defined(HAS_SAFE_BCOPY)
 p	|char*	|my_bcopy	|const char* from|char* to|I32 len
 #endif
@@ -1127,7 +1127,7 @@ p	|SV*	|newSV		|STRLEN len
 p	|OP*	|newSVREF	|OP* o
 p	|OP*	|newSVOP	|I32 type|I32 flags|SV* sv
 p	|SV*	|newSViv	|IV i
-p	|SV*	|newSVnv	|double n
+p	|SV*	|newSVnv	|NV n
 p	|SV*	|newSVpv	|const char* s|STRLEN len
 p	|SV*	|newSVpvn	|const char* s|STRLEN len
 p	|SV*	|newSVpvf	|const char* pat|...
@@ -1289,12 +1289,12 @@ p	|CV*	|sv_2cv		|SV* sv|HV** st|GV** gvp|I32 lref
 p	|IO*	|sv_2io		|SV* sv
 p	|IV	|sv_2iv		|SV* sv
 p	|SV*	|sv_2mortal	|SV* sv
-p	|double	|sv_2nv		|SV* sv
+p	|NV	|sv_2nv		|SV* sv
 p	|char*	|sv_2pv		|SV* sv|STRLEN* lp
 p	|UV	|sv_2uv		|SV* sv
 p	|IV	|sv_iv		|SV* sv
 p	|UV	|sv_uv		|SV* sv
-p	|double	|sv_nv		|SV* sv
+p	|NV	|sv_nv		|SV* sv
 p	|char*	|sv_pvn		|SV *sv|STRLEN *len
 p	|I32	|sv_true	|SV *sv
 p	|void	|sv_add_arena	|char* ptr|U32 size|U32 flags
@@ -1346,9 +1346,9 @@ p	|void	|sv_setpvf	|SV* sv|const char* pat|...
 p	|void	|sv_setiv	|SV* sv|IV num
 p	|void	|sv_setpviv	|SV* sv|IV num
 p	|void	|sv_setuv	|SV* sv|UV num
-p	|void	|sv_setnv	|SV* sv|double num
+p	|void	|sv_setnv	|SV* sv|NV num
 p	|SV*	|sv_setref_iv	|SV* rv|const char* classname|IV iv
-p	|SV*	|sv_setref_nv	|SV* rv|const char* classname|double nv
+p	|SV*	|sv_setref_nv	|SV* rv|const char* classname|NV nv
 p	|SV*	|sv_setref_pv	|SV* rv|const char* classname|void* pv
 p	|SV*	|sv_setref_pvn	|SV* rv|const char* classname|char* pv \
 				|STRLEN n
@@ -1445,7 +1445,7 @@ p	|void	|sv_setpvf_mg	|SV *sv|const char* pat|...
 p	|void	|sv_setiv_mg	|SV *sv|IV i
 p	|void	|sv_setpviv_mg	|SV *sv|IV iv
 p	|void	|sv_setuv_mg	|SV *sv|UV u
-p	|void	|sv_setnv_mg	|SV *sv|double num
+p	|void	|sv_setnv_mg	|SV *sv|NV num
 p	|void	|sv_setpv_mg	|SV *sv|const char *ptr
 p	|void	|sv_setpvn_mg	|SV *sv|const char *ptr|STRLEN len
 p	|void	|sv_setsv_mg	|SV *dstr|SV *sstr
diff --git a/ext/ByteLoader/bytecode.h b/ext/ByteLoader/bytecode.h
index 9d597fbed2..04a05e4251 100644
--- a/ext/ByteLoader/bytecode.h
+++ b/ext/ByteLoader/bytecode.h
@@ -70,10 +70,10 @@ typedef IV IV64;
 	arg = PL_tokenbuf;			\
     } STMT_END
 
-#define BGET_double(arg) STMT_START {	\
+#define BGET_NV(arg) STMT_START {	\
 	char *str;			\
 	BGET_strconst(str);		\
-	arg = atof(str);		\
+	arg = Perl_atonv(str);		\
     } STMT_END
 
 #define BGET_objindex(arg, type) STMT_START {	\
diff --git a/ext/ByteLoader/byterun.c b/ext/ByteLoader/byterun.c
index 544a59f042..035578f424 100644
--- a/ext/ByteLoader/byterun.c
+++ b/ext/ByteLoader/byterun.c
@@ -221,8 +221,8 @@ byterun(pTHXo_ struct bytestream bs)
 	    }
 	  case INSN_XNV:		/* 21 */
 	    {
-		double arg;
-		BGET_double(arg);
+		NV arg;
+		BGET_NV(arg);
 		SvNVX(bytecode_sv) = arg;
 		break;
 	    }
diff --git a/hv.h b/hv.h
index e9772d4440..3977b1c395 100644
--- a/hv.h
+++ b/hv.h
@@ -28,7 +28,7 @@ struct xpvhv {
     STRLEN	xhv_fill;	/* how full xhv_array currently is */
     STRLEN	xhv_max;	/* subscript of last element of xhv_array */
     IV		xhv_keys;	/* how many elements in the array */
-    double	xnv_nv;		/* numeric value, if any */
+    NV		xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* magic for scalar array */
     HV*		xmg_stash;	/* class package */
 
diff --git a/intrpvar.h b/intrpvar.h
index 0bf826e79a..5cff858675 100644
--- a/intrpvar.h
+++ b/intrpvar.h
@@ -219,7 +219,7 @@ PERLVAR(Isighandlerp,	Sighandler_t)
 
 PERLVAR(Ixiv_arenaroot,	XPV*)		/* list of allocated xiv areas */
 PERLVAR(Ixiv_root,	IV *)		/* free xiv list--shared by interpreters */
-PERLVAR(Ixnv_root,	double *)	/* free xnv list--shared by interpreters */
+PERLVAR(Ixnv_root,	NV *)		/* free xnv list--shared by interpreters */
 PERLVAR(Ixrv_root,	XRV *)		/* free xrv list--shared by interpreters */
 PERLVAR(Ixpv_root,	XPV *)		/* free xpv list--shared by interpreters */
 PERLVAR(Ihe_root,	HE *)		/* free he list--shared by interpreters */
diff --git a/mg.c b/mg.c
index a21ea5730e..0e9ca198e7 100644
--- a/mg.c
+++ b/mg.c
@@ -498,7 +498,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 #	    include <starlet.h>
 	    char msg[255];
 	    $DESCRIPTOR(msgdsc,msg);
-	    sv_setnv(sv,(double) vaxc$errno);
+	    sv_setnv(sv,(NV) vaxc$errno);
 	    if (sys$getmsg(vaxc$errno,&msgdsc.dsc$w_length,&msgdsc,0,0) & 1)
 		sv_setpvn(sv,msgdsc.dsc$a_pointer,msgdsc.dsc$w_length);
 	    else
@@ -507,7 +507,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 #else
 #ifdef OS2
 	if (!(_emx_env & 0x200)) {	/* Under DOS */
-	    sv_setnv(sv, (double)errno);
+	    sv_setnv(sv, (NV)errno);
 	    sv_setpv(sv, errno ? Strerror(errno) : "");
 	} else {
 	    if (errno != errno_isOS2) {
@@ -515,14 +515,14 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 		if (tmp)	/* 2nd call to _syserrno() makes it 0 */
 		    Perl_rc = tmp;
 	    }
-	    sv_setnv(sv, (double)Perl_rc);
+	    sv_setnv(sv, (NV)Perl_rc);
 	    sv_setpv(sv, os2error(Perl_rc));
 	}
 #else
 #ifdef WIN32
 	{
 	    DWORD dwErr = GetLastError();
-	    sv_setnv(sv, (double)dwErr);
+	    sv_setnv(sv, (NV)dwErr);
 	    if (dwErr)
 	    {
 		PerlProc_GetOSError(sv, dwErr);
@@ -532,7 +532,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	    SetLastError(dwErr);
 	}
 #else
-	sv_setnv(sv, (double)errno);
+	sv_setnv(sv, (NV)errno);
 	sv_setpv(sv, errno ? Strerror(errno) : "");
 #endif
 #endif
@@ -701,12 +701,12 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	break;
     case '!':
 #ifdef VMS
-	sv_setnv(sv, (double)((errno == EVMSERR) ? vaxc$errno : errno));
+	sv_setnv(sv, (NV)((errno == EVMSERR) ? vaxc$errno : errno));
 	sv_setpv(sv, errno ? Strerror(errno) : "");
 #else
 	{
 	int saveerrno = errno;
-	sv_setnv(sv, (double)errno);
+	sv_setnv(sv, (NV)errno);
 #ifdef OS2
 	if (errno == errno_isOS2) sv_setpv(sv, os2error(Perl_rc));
 	else
diff --git a/op.c b/op.c
index 25b17dc1e1..091a768dcd 100644
--- a/op.c
+++ b/op.c
@@ -192,7 +192,7 @@ Perl_pad_allocmy(pTHX_ char *name)
 	PL_sv_objcount++;
     }
     av_store(PL_comppad_name, off, sv);
-    SvNVX(sv) = (double)PAD_MAX;
+    SvNVX(sv) = (NV)PAD_MAX;
     SvIVX(sv) = 0;			/* Not yet introduced--see newSTATEOP */
     if (!PL_min_intro_pending)
 	PL_min_intro_pending = off;
@@ -255,7 +255,7 @@ S_pad_findlex(pTHX_ char *name, PADOFFSET newoff, U32 seq, CV* startcv,
 		    sv_upgrade(namesv, SVt_PVNV);
 		    sv_setpv(namesv, name);
 		    av_store(PL_comppad_name, newoff, namesv);
-		    SvNVX(namesv) = (double)PL_curcop->cop_seq;
+		    SvNVX(namesv) = (NV)PL_curcop->cop_seq;
 		    SvIVX(namesv) = PAD_MAX;	/* A ref, intro immediately */
 		    SvFAKE_on(namesv);		/* A ref, not a real var */
 		    if (SvOBJECT(sv)) {		/* A typed var */
@@ -1899,7 +1899,7 @@ Perl_fold_constants(pTHX_ register OP *o)
 	    type != OP_NEGATE)
 	{
 	    IV iv = SvIV(sv);
-	    if ((double)iv == SvNV(sv)) {
+	    if ((NV)iv == SvNV(sv)) {
 		SvREFCNT_dec(sv);
 		sv = newSViv(iv);
 	    }
@@ -3083,7 +3083,7 @@ Perl_intro_my(pTHX)
     for (i = PL_min_intro_pending; i <= PL_max_intro_pending; i++) {
 	if ((sv = svp[i]) && sv != &PL_sv_undef && !SvIVX(sv)) {
 	    SvIVX(sv) = PAD_MAX;	/* Don't know scope end yet. */
-	    SvNVX(sv) = (double)PL_cop_seqmax;
+	    SvNVX(sv) = (NV)PL_cop_seqmax;
 	}
     }
     PL_min_intro_pending = 0;
diff --git a/perl.h b/perl.h
index 558d423dab..5eb7b1dbe1 100644
--- a/perl.h
+++ b/perl.h
@@ -997,6 +997,43 @@ Free_t   Perl_mfree (Malloc_t where);
 #  endif
 #endif
 
+#ifdef USE_LONG_DOUBLE
+#  if defined(HAS_LONG_DOUBLE) && (LONG_DOUBLESIZE > DOUBLESIZE)
+#    define LDoub_t long double
+#  endif
+#endif
+
+#ifdef USE_LONG_DOUBLE
+#   define HAS_LDOUB
+    typedef LDoub_t NV;
+#   define Perl_modf modfl
+#   define Perl_frexp frexpl
+#   define Perl_cos cosl
+#   define Perl_sin sinl
+#   define Perl_sqrt sqrtl
+#   define Perl_exp expl
+#   define Perl_log logl
+#   define Perl_atan2 atan2l
+#   define Perl_pow powl
+#   define Perl_floor floorl
+#   define Perl_atof atof
+#   define Perl_fmod fmodl
+#else
+    typedef double NV;
+#   define Perl_modf modf
+#   define Perl_frexp frexp
+#   define Perl_cos cos
+#   define Perl_sin sin
+#   define Perl_sqrt sqrt
+#   define Perl_exp exp
+#   define Perl_log log
+#   define Perl_atan2 atan2
+#   define Perl_pow pow
+#   define Perl_floor floor
+#   define Perl_atof atof		/* At some point there may be an atolf */
+#   define Perl_fmod fmod
+#endif
+
 /* Previously these definitions used hardcoded figures. 
  * It is hoped these formula are more portable, although
  * no data one way or another is presently known to me.
@@ -1728,9 +1765,9 @@ typedef I32 CHECKPOINT;
 #define U_I(what) ((unsigned int)(what))
 #define U_L(what) ((U32)(what))
 #else
-#define U_S(what) ((U16)cast_ulong((double)(what)))
-#define U_I(what) ((unsigned int)cast_ulong((double)(what)))
-#define U_L(what) (cast_ulong((double)(what)))
+#define U_S(what) ((U16)cast_ulong((NV)(what)))
+#define U_I(what) ((unsigned int)cast_ulong((NV)(what)))
+#define U_L(what) (cast_ulong((NV)(what)))
 #endif
 
 #ifdef CASTI32
@@ -1738,9 +1775,9 @@ typedef I32 CHECKPOINT;
 #define I_V(what) ((IV)(what))
 #define U_V(what) ((UV)(what))
 #else
-#define I_32(what) (cast_i32((double)(what)))
-#define I_V(what) (cast_iv((double)(what)))
-#define U_V(what) (cast_uv((double)(what)))
+#define I_32(what) (cast_i32((NV)(what)))
+#define I_V(what) (cast_iv((NV)(what)))
+#define U_V(what) (cast_uv((NV)(what)))
 #endif
 
 /* Used with UV/IV arguments: */
@@ -2879,7 +2916,7 @@ typedef struct am_table_short AMTS;
 #define IS_NUMERIC_RADIX(c)		(0)
 #define RESTORE_NUMERIC_LOCAL()		/**/
 #define RESTORE_NUMERIC_STANDARD()	/**/
-#define Atof				atof
+#define Atof				Perl_atof
 
 #endif /* !USE_LOCALE_NUMERIC */
 
diff --git a/pp.c b/pp.c
index adf3d7308b..e688848d9c 100644
--- a/pp.c
+++ b/pp.c
@@ -943,15 +943,15 @@ PP(pp_divide)
     djSP; dATARGET; tryAMAGICbin(div,opASSIGN);
     {
       dPOPPOPnnrl;
-      double value;
+      NV value;
       if (right == 0.0)
 	DIE(aTHX_ "Illegal division by zero");
 #ifdef SLOPPYDIVIDE
       /* insure that 20./5. == 4. */
       {
 	IV k;
-	if ((double)I_V(left)  == left &&
-	    (double)I_V(right) == right &&
+	if ((NV)I_V(left)  == left &&
+	    (NV)I_V(right) == right &&
 	    (k = I_V(left)/I_V(right))*I_V(right) == I_V(left)) {
 	    value = k;
 	}
@@ -976,8 +976,8 @@ PP(pp_modulo)
 	bool left_neg;
 	bool right_neg;
 	bool use_double = 0;
-	double dright;
-	double dleft;
+	NV dright;
+	NV dleft;
 
 	if (SvIOK(TOPs) && !SvNOK(TOPs) && !SvPOK(TOPs)) {
 	    IV i = SvIVX(POPs);
@@ -1007,7 +1007,7 @@ PP(pp_modulo)
 	}
 
 	if (use_double) {
-	    double dans;
+	    NV dans;
 
 #if 1
 /* Somehow U_V is pessimized even if CASTFLAGS is 0 */
@@ -1034,7 +1034,7 @@ PP(pp_modulo)
 	    if (!dright)
 		DIE(aTHX_ "Illegal modulus zero");
 
-	    dans = fmod(dleft, dright);
+	    dans = Perl_fmod(dleft, dright);
 	    if ((left_neg != right_neg) && dans)
 		dans = dright - dans;
 	    if (right_neg)
@@ -1057,7 +1057,7 @@ PP(pp_modulo)
 		if (ans <= ~((UV)IV_MAX)+1)
 		    sv_setiv(TARG, ~ans+1);
 		else
-		    sv_setnv(TARG, -(double)ans);
+		    sv_setnv(TARG, -(NV)ans);
 	    }
 	    else
 		sv_setuv(TARG, ans);
@@ -1624,7 +1624,7 @@ PP(pp_atan2)
     djSP; dTARGET; tryAMAGICbin(atan2,0);
     {
       dPOPTOPnnrl;
-      SETn(atan2(left, right));
+      SETn(Perl_atan2(left, right));
       RETURN;
     }
 }
@@ -1633,9 +1633,9 @@ PP(pp_sin)
 {
     djSP; dTARGET; tryAMAGICun(sin);
     {
-      double value;
+      NV value;
       value = POPn;
-      value = sin(value);
+      value = Perl_sin(value);
       XPUSHn(value);
       RETURN;
     }
@@ -1645,9 +1645,9 @@ PP(pp_cos)
 {
     djSP; dTARGET; tryAMAGICun(cos);
     {
-      double value;
+      NV value;
       value = POPn;
-      value = cos(value);
+      value = Perl_cos(value);
       XPUSHn(value);
       RETURN;
     }
@@ -1671,7 +1671,7 @@ extern double drand48 (void);
 PP(pp_rand)
 {
     djSP; dTARGET;
-    double value;
+    NV value;
     if (MAXARG < 1)
 	value = 1.0;
     else
@@ -1787,9 +1787,9 @@ PP(pp_exp)
 {
     djSP; dTARGET; tryAMAGICun(exp);
     {
-      double value;
+      NV value;
       value = POPn;
-      value = exp(value);
+      value = Perl_exp(value);
       XPUSHn(value);
       RETURN;
     }
@@ -1799,13 +1799,13 @@ PP(pp_log)
 {
     djSP; dTARGET; tryAMAGICun(log);
     {
-      double value;
+      NV value;
       value = POPn;
       if (value <= 0.0) {
 	RESTORE_NUMERIC_STANDARD();
 	DIE(aTHX_ "Can't take log of %g", value);
       }
-      value = log(value);
+      value = Perl_log(value);
       XPUSHn(value);
       RETURN;
     }
@@ -1815,13 +1815,13 @@ PP(pp_sqrt)
 {
     djSP; dTARGET; tryAMAGICun(sqrt);
     {
-      double value;
+      NV value;
       value = POPn;
       if (value < 0.0) {
 	RESTORE_NUMERIC_STANDARD();
 	DIE(aTHX_ "Can't take sqrt of %g", value);
       }
-      value = sqrt(value);
+      value = Perl_sqrt(value);
       XPUSHn(value);
       RETURN;
     }
@@ -1831,7 +1831,7 @@ PP(pp_int)
 {
     djSP; dTARGET;
     {
-      double value = TOPn;
+      NV value = TOPn;
       IV iv;
 
       if (SvIOKp(TOPs) && !SvNOKp(TOPs) && !SvPOKp(TOPs)) {
@@ -1840,9 +1840,9 @@ PP(pp_int)
       }
       else {
 	if (value >= 0.0)
-	  (void)modf(value, &value);
+	  (void)Perl_modf(value, &value);
 	else {
-	  (void)modf(-value, &value);
+	  (void)Perl_modf(-value, &value);
 	  value = -value;
 	}
 	iv = I_V(value);
@@ -1859,7 +1859,7 @@ PP(pp_abs)
 {
     djSP; dTARGET; tryAMAGICun(abs);
     {
-      double value = TOPn;
+      NV value = TOPn;
       IV iv;
 
       if (SvIOKp(TOPs) && !SvNOKp(TOPs) && !SvPOKp(TOPs) &&
@@ -3301,7 +3301,7 @@ PP(pp_unpack)
     double adouble;
     I32 checksum = 0;
     register U32 culong;
-    double cdouble;
+    NV cdouble;
     int commas = 0;
 #ifdef PERL_NATINT_PACK
     int natint;		/* native integer */
@@ -3565,7 +3565,7 @@ PP(pp_unpack)
 		    auint = utf8_to_uv((U8*)s, &along);
 		    s += along;
 		    if (checksum > 32)
-			cdouble += (double)auint;
+			cdouble += (NV)auint;
 		    else
 			culong += auint;
 		}
@@ -3725,7 +3725,7 @@ PP(pp_unpack)
 		    Copy(s, &aint, 1, int);
 		    s += sizeof(int);
 		    if (checksum > 32)
-			cdouble += (double)aint;
+			cdouble += (NV)aint;
 		    else
 			culong += aint;
 		}
@@ -3776,7 +3776,7 @@ PP(pp_unpack)
 		    Copy(s, &auint, 1, unsigned int);
 		    s += sizeof(unsigned int);
 		    if (checksum > 32)
-			cdouble += (double)auint;
+			cdouble += (NV)auint;
 		    else
 			culong += auint;
 		}
@@ -3815,7 +3815,7 @@ PP(pp_unpack)
 			COPYNN(s, &along, sizeof(long));
 			s += sizeof(long);
 			if (checksum > 32)
-			    cdouble += (double)along;
+			    cdouble += (NV)along;
 			else
 			    culong += along;
 		    }
@@ -3831,7 +3831,7 @@ PP(pp_unpack)
 #endif
 			s += SIZE32;
 			if (checksum > 32)
-			    cdouble += (double)along;
+			    cdouble += (NV)along;
 			else
 			    culong += along;
 		    }
@@ -3885,7 +3885,7 @@ PP(pp_unpack)
 			COPYNN(s, &aulong, sizeof(unsigned long));
 			s += sizeof(unsigned long);
 			if (checksum > 32)
-			    cdouble += (double)aulong;
+			    cdouble += (NV)aulong;
 			else
 			    culong += aulong;
 		    }
@@ -3905,7 +3905,7 @@ PP(pp_unpack)
 			    aulong = vtohl(aulong);
 #endif
 			if (checksum > 32)
-			    cdouble += (double)aulong;
+			    cdouble += (NV)aulong;
 			else
 			    culong += aulong;
 		    }
@@ -4037,7 +4037,7 @@ PP(pp_unpack)
 		if (aquad >= IV_MIN && aquad <= IV_MAX)
 		    sv_setiv(sv, (IV)aquad);
 		else
-		    sv_setnv(sv, (double)aquad);
+		    sv_setnv(sv, (NV)aquad);
 		PUSHs(sv_2mortal(sv));
 	    }
 	    break;
@@ -4058,7 +4058,7 @@ PP(pp_unpack)
 		if (auquad <= UV_MAX)
 		    sv_setuv(sv, (UV)auquad);
 		else
-		    sv_setnv(sv, (double)auquad);
+		    sv_setnv(sv, (NV)auquad);
 		PUSHs(sv_2mortal(sv));
 	    }
 	    break;
@@ -4083,7 +4083,7 @@ PP(pp_unpack)
 		    Copy(s, &afloat, 1, float);
 		    s += sizeof(float);
 		    sv = NEWSV(47, 0);
-		    sv_setnv(sv, (double)afloat);
+		    sv_setnv(sv, (NV)afloat);
 		    PUSHs(sv_2mortal(sv));
 		}
 	    }
@@ -4107,7 +4107,7 @@ PP(pp_unpack)
 		    Copy(s, &adouble, 1, double);
 		    s += sizeof(double);
 		    sv = NEWSV(48, 0);
-		    sv_setnv(sv, (double)adouble);
+		    sv_setnv(sv, (NV)adouble);
 		    PUSHs(sv_2mortal(sv));
 		}
 	    }
@@ -4175,7 +4175,7 @@ PP(pp_unpack)
 	    sv = NEWSV(42, 0);
 	    if (strchr("fFdD", datumtype) ||
 	      (checksum > 32 && strchr("iIlLNU", datumtype)) ) {
-		double trouble;
+		NV trouble;
 
 		adouble = 1.0;
 		while (checksum >= 16) {
@@ -4191,7 +4191,7 @@ PP(pp_unpack)
 		along = (1 << checksum) - 1;
 		while (cdouble < 0.0)
 		    cdouble += adouble;
-		cdouble = modf(cdouble / adouble, &trouble) * adouble;
+		cdouble = Perl_modf(cdouble / adouble, &trouble) * adouble;
 		sv_setnv(sv, cdouble);
 	    }
 	    else {
@@ -4668,7 +4668,7 @@ PP(pp_pack)
 	case 'w':
             while (len-- > 0) {
 		fromstr = NEXTFROM;
-		adouble = floor(SvNV(fromstr));
+		adouble = Perl_floor(SvNV(fromstr));
 
 		if (adouble < 0)
 		    Perl_croak(aTHX_ "Cannot compress negative numbers");
diff --git a/pp.h b/pp.h
index ca8dc35640..9fd3365361 100644
--- a/pp.h
+++ b/pp.h
@@ -88,43 +88,43 @@
 #define PUSHs(s)	(*++sp = (s))
 #define PUSHTARG	STMT_START { SvSETMAGIC(TARG); PUSHs(TARG); } STMT_END
 #define PUSHp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); PUSHTARG; } STMT_END
-#define PUSHn(n)	STMT_START { sv_setnv(TARG, (double)(n)); PUSHTARG; } STMT_END
+#define PUSHn(n)	STMT_START { sv_setnv(TARG, (NV)(n)); PUSHTARG; } STMT_END
 #define PUSHi(i)	STMT_START { sv_setiv(TARG, (IV)(i)); PUSHTARG; } STMT_END
 #define PUSHu(u)	STMT_START { sv_setuv(TARG, (UV)(u)); PUSHTARG; } STMT_END
 
 #define XPUSHs(s)	STMT_START { EXTEND(sp,1); (*++sp = (s)); } STMT_END
 #define XPUSHTARG	STMT_START { SvSETMAGIC(TARG); XPUSHs(TARG); } STMT_END
 #define XPUSHp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); XPUSHTARG; } STMT_END
-#define XPUSHn(n)	STMT_START { sv_setnv(TARG, (double)(n)); XPUSHTARG; } STMT_END
+#define XPUSHn(n)	STMT_START { sv_setnv(TARG, (NV)(n)); XPUSHTARG; } STMT_END
 #define XPUSHi(i)	STMT_START { sv_setiv(TARG, (IV)(i)); XPUSHTARG; } STMT_END
 #define XPUSHu(u)	STMT_START { sv_setuv(TARG, (UV)(u)); XPUSHTARG; } STMT_END
 
 #define SETs(s)		(*sp = s)
 #define SETTARG		STMT_START { SvSETMAGIC(TARG); SETs(TARG); } STMT_END
 #define SETp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); SETTARG; } STMT_END
-#define SETn(n)		STMT_START { sv_setnv(TARG, (double)(n)); SETTARG; } STMT_END
+#define SETn(n)		STMT_START { sv_setnv(TARG, (NV)(n)); SETTARG; } STMT_END
 #define SETi(i)		STMT_START { sv_setiv(TARG, (IV)(i)); SETTARG; } STMT_END
 #define SETu(u)		STMT_START { sv_setuv(TARG, (UV)(u)); SETTARG; } STMT_END
 
 #define dTOPss		SV *sv = TOPs
 #define dPOPss		SV *sv = POPs
-#define dTOPnv		double value = TOPn
-#define dPOPnv		double value = POPn
+#define dTOPnv		NV value = TOPn
+#define dPOPnv		NV value = POPn
 #define dTOPiv		IV value = TOPi
 #define dPOPiv		IV value = POPi
 #define dTOPuv		UV value = TOPu
 #define dPOPuv		UV value = POPu
 
 #define dPOPXssrl(X)	SV *right = POPs; SV *left = CAT2(X,s)
-#define dPOPXnnrl(X)	double right = POPn; double left = CAT2(X,n)
+#define dPOPXnnrl(X)	NV right = POPn; NV left = CAT2(X,n)
 #define dPOPXiirl(X)	IV right = POPi; IV left = CAT2(X,i)
 
 #define USE_LEFT(sv) \
 	(SvOK(sv) || SvGMAGICAL(sv) || !(PL_op->op_flags & OPf_STACKED))
 #define dPOPXnnrl_ul(X)	\
-    double right = POPn;				\
+    NV right = POPn;				\
     SV *leftsv = CAT2(X,s);				\
-    double left = USE_LEFT(leftsv) ? SvNV(leftsv) : 0.0
+    NV left = USE_LEFT(leftsv) ? SvNV(leftsv) : 0.0
 #define dPOPXiirl_ul(X) \
     IV right = POPi;					\
     SV *leftsv = CAT2(X,s);				\
diff --git a/pp_ctl.c b/pp_ctl.c
index 64e695bc2e..21d03351ef 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -276,7 +276,7 @@ PP(pp_formline)
     bool chopspace = (strchr(PL_chopset, ' ') != Nullch);
     char *chophere;
     char *linemark;
-    double value;
+    NV value;
     bool gotsome;
     STRLEN len;
     STRLEN fudge = SvCUR(tmpForm) * (IN_UTF8 ? 3 : 1) + 1;
@@ -569,6 +569,14 @@ PP(pp_formline)
 	    /* Formats aren't yet marked for locales, so assume "yes". */
 	    {
 		RESTORE_NUMERIC_LOCAL();
+#if defined(USE_LONG_DOUBLE)
+		if (arg & 256) {
+		    sprintf(t, "%#*.*Lf",
+			    (int) fieldsize, (int) arg & 255, value);
+		} else {
+		    sprintf(t, "%*.0Lf", (int) fieldsize, value);
+		}
+#else
 		if (arg & 256) {
 		    sprintf(t, "%#*.*f",
 			    (int) fieldsize, (int) arg & 255, value);
@@ -576,6 +584,7 @@ PP(pp_formline)
 		    sprintf(t, "%*.0f",
 			    (int) fieldsize, value);
 		}
+#endif
 		RESTORE_NUMERIC_STANDARD();
 	    }
 	    t += fieldsize;
@@ -749,8 +758,8 @@ PP(pp_mapwhile)
 STATIC I32
 S_sv_ncmp(pTHX_ SV *a, SV *b)
 {
-    double nv1 = SvNV(a);
-    double nv2 = SvNV(b);
+    NV nv1 = SvNV(a);
+    NV nv2 = SvNV(b);
     return nv1 < nv2 ? -1 : nv1 > nv2 ? 1 : 0;
 }
 
@@ -778,7 +787,7 @@ S_amagic_ncmp(pTHX_ register SV *a, register SV *b)
     SV *tmpsv;
     tryCALL_AMAGICbin(a,b,ncmp,&tmpsv);
     if (tmpsv) {
-    	double d;
+    	NV d;
     	
         if (SvIOK(tmpsv)) {
             I32 i = SvIVX(tmpsv);
@@ -800,7 +809,7 @@ S_amagic_i_ncmp(pTHX_ register SV *a, register SV *b)
     SV *tmpsv;
     tryCALL_AMAGICbin(a,b,ncmp,&tmpsv);
     if (tmpsv) {
-    	double d;
+    	NV d;
     	
         if (SvIOK(tmpsv)) {
             I32 i = SvIVX(tmpsv);
@@ -822,7 +831,7 @@ S_amagic_cmp(pTHX_ register SV *str1, register SV *str2)
     SV *tmpsv;
     tryCALL_AMAGICbin(str1,str2,scmp,&tmpsv);
     if (tmpsv) {
-    	double d;
+    	NV d;
     	
         if (SvIOK(tmpsv)) {
             I32 i = SvIVX(tmpsv);
@@ -844,7 +853,7 @@ S_amagic_cmp_locale(pTHX_ register SV *str1, register SV *str2)
     SV *tmpsv;
     tryCALL_AMAGICbin(str1,str2,scmp,&tmpsv);
     if (tmpsv) {
-    	double d;
+    	NV d;
     	
         if (SvIOK(tmpsv)) {
             I32 i = SvIVX(tmpsv);
@@ -2464,11 +2473,11 @@ PP(pp_exit)
 PP(pp_nswitch)
 {
     djSP;
-    double value = SvNVx(GvSV(cCOP->cop_gv));
+    NV value = SvNVx(GvSV(cCOP->cop_gv));
     register I32 match = I_32(value);
 
     if (value < 0.0) {
-	if (((double)match) > value)
+	if (((NV)match) > value)
 	    --match;		/* was fractional--truncate other way */
     }
     match -= cCOP->uop.scop.scop_offset;
diff --git a/pp_sys.c b/pp_sys.c
index 5bb0ca30d4..a2ed109a4d 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -906,7 +906,7 @@ PP(pp_sselect)
     register I32 j;
     register char *s;
     register SV *sv;
-    double value;
+    NV value;
     I32 maxlen = 0;
     I32 nfound;
     struct timeval timebuf;
@@ -969,7 +969,7 @@ PP(pp_sselect)
 	if (value < 0.0)
 	    value = 0.0;
 	timebuf.tv_sec = (long)value;
-	value -= (double)timebuf.tv_sec;
+	value -= (NV)timebuf.tv_sec;
 	timebuf.tv_usec = (long)(value * 1000000.0);
     }
     else
@@ -1028,8 +1028,8 @@ PP(pp_sselect)
 
     PUSHi(nfound);
     if (GIMME == G_ARRAY && tbuf) {
-	value = (double)(timebuf.tv_sec) +
-		(double)(timebuf.tv_usec) / 1000000.0;
+	value = (NV)(timebuf.tv_sec) +
+		(NV)(timebuf.tv_usec) / 1000000.0;
 	PUSHs(sv = sv_mortalcopy(&PL_sv_no));
 	sv_setnv(sv, value);
     }
@@ -3826,11 +3826,11 @@ PP(pp_tms)
                                                    /* is returned.                   */
 #endif
 
-    PUSHs(sv_2mortal(newSVnv(((double)PL_timesbuf.tms_utime)/HZ)));
+    PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_utime)/HZ)));
     if (GIMME == G_ARRAY) {
-	PUSHs(sv_2mortal(newSVnv(((double)PL_timesbuf.tms_stime)/HZ)));
-	PUSHs(sv_2mortal(newSVnv(((double)PL_timesbuf.tms_cutime)/HZ)));
-	PUSHs(sv_2mortal(newSVnv(((double)PL_timesbuf.tms_cstime)/HZ)));
+	PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_stime)/HZ)));
+	PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_cutime)/HZ)));
+	PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_cstime)/HZ)));
     }
     RETURN;
 #endif /* HAS_TIMES */
diff --git a/proto.h b/proto.h
index 95ffda5132..eae128ac0e 100644
--- a/proto.h
+++ b/proto.h
@@ -39,10 +39,10 @@ VIRTUAL int	Perl_block_start(pTHX_ int full);
 VIRTUAL void	Perl_boot_core_UNIVERSAL(pTHX);
 VIRTUAL void	Perl_call_list(pTHX_ I32 oldscope, AV* av_list);
 VIRTUAL I32	Perl_cando(pTHX_ I32 bit, I32 effective, Stat_t* statbufp);
-VIRTUAL U32	Perl_cast_ulong(pTHX_ double f);
-VIRTUAL I32	Perl_cast_i32(pTHX_ double f);
-VIRTUAL IV	Perl_cast_iv(pTHX_ double f);
-VIRTUAL UV	Perl_cast_uv(pTHX_ double f);
+VIRTUAL U32	Perl_cast_ulong(pTHX_ NV f);
+VIRTUAL I32	Perl_cast_i32(pTHX_ NV f);
+VIRTUAL IV	Perl_cast_iv(pTHX_ NV f);
+VIRTUAL UV	Perl_cast_uv(pTHX_ NV f);
 #if !defined(HAS_TRUNCATE) && !defined(HAS_CHSIZE) && defined(F_FREESP)
 VIRTUAL I32	Perl_my_chsize(pTHX_ int fd, Off_t length);
 #endif
@@ -307,7 +307,7 @@ VIRTUAL I32	Perl_mg_size(pTHX_ SV* sv);
 VIRTUAL OP*	Perl_mod(pTHX_ OP* o, I32 type);
 VIRTUAL char*	Perl_moreswitches(pTHX_ char* s);
 VIRTUAL OP*	Perl_my(pTHX_ OP* o);
-VIRTUAL double	Perl_my_atof(pTHX_ const char *s);
+VIRTUAL NV	Perl_my_atof(pTHX_ const char *s);
 #if !defined(HAS_BCOPY) || !defined(HAS_SAFE_BCOPY)
 VIRTUAL char*	Perl_my_bcopy(pTHX_ const char* from, char* to, I32 len);
 #endif
@@ -375,7 +375,7 @@ VIRTUAL SV*	Perl_newSV(pTHX_ STRLEN len);
 VIRTUAL OP*	Perl_newSVREF(pTHX_ OP* o);
 VIRTUAL OP*	Perl_newSVOP(pTHX_ I32 type, I32 flags, SV* sv);
 VIRTUAL SV*	Perl_newSViv(pTHX_ IV i);
-VIRTUAL SV*	Perl_newSVnv(pTHX_ double n);
+VIRTUAL SV*	Perl_newSVnv(pTHX_ NV n);
 VIRTUAL SV*	Perl_newSVpv(pTHX_ const char* s, STRLEN len);
 VIRTUAL SV*	Perl_newSVpvn(pTHX_ const char* s, STRLEN len);
 VIRTUAL SV*	Perl_newSVpvf(pTHX_ const char* pat, ...);
@@ -527,12 +527,12 @@ VIRTUAL CV*	Perl_sv_2cv(pTHX_ SV* sv, HV** st, GV** gvp, I32 lref);
 VIRTUAL IO*	Perl_sv_2io(pTHX_ SV* sv);
 VIRTUAL IV	Perl_sv_2iv(pTHX_ SV* sv);
 VIRTUAL SV*	Perl_sv_2mortal(pTHX_ SV* sv);
-VIRTUAL double	Perl_sv_2nv(pTHX_ SV* sv);
+VIRTUAL NV	Perl_sv_2nv(pTHX_ SV* sv);
 VIRTUAL char*	Perl_sv_2pv(pTHX_ SV* sv, STRLEN* lp);
 VIRTUAL UV	Perl_sv_2uv(pTHX_ SV* sv);
 VIRTUAL IV	Perl_sv_iv(pTHX_ SV* sv);
 VIRTUAL UV	Perl_sv_uv(pTHX_ SV* sv);
-VIRTUAL double	Perl_sv_nv(pTHX_ SV* sv);
+VIRTUAL NV	Perl_sv_nv(pTHX_ SV* sv);
 VIRTUAL char*	Perl_sv_pvn(pTHX_ SV *sv, STRLEN *len);
 VIRTUAL I32	Perl_sv_true(pTHX_ SV *sv);
 VIRTUAL void	Perl_sv_add_arena(pTHX_ char* ptr, U32 size, U32 flags);
@@ -582,9 +582,9 @@ VIRTUAL void	Perl_sv_setpvf(pTHX_ SV* sv, const char* pat, ...);
 VIRTUAL void	Perl_sv_setiv(pTHX_ SV* sv, IV num);
 VIRTUAL void	Perl_sv_setpviv(pTHX_ SV* sv, IV num);
 VIRTUAL void	Perl_sv_setuv(pTHX_ SV* sv, UV num);
-VIRTUAL void	Perl_sv_setnv(pTHX_ SV* sv, double num);
+VIRTUAL void	Perl_sv_setnv(pTHX_ SV* sv, NV num);
 VIRTUAL SV*	Perl_sv_setref_iv(pTHX_ SV* rv, const char* classname, IV iv);
-VIRTUAL SV*	Perl_sv_setref_nv(pTHX_ SV* rv, const char* classname, double nv);
+VIRTUAL SV*	Perl_sv_setref_nv(pTHX_ SV* rv, const char* classname, NV nv);
 VIRTUAL SV*	Perl_sv_setref_pv(pTHX_ SV* rv, const char* classname, void* pv);
 VIRTUAL SV*	Perl_sv_setref_pvn(pTHX_ SV* rv, const char* classname, char* pv, STRLEN n);
 VIRTUAL void	Perl_sv_setpv(pTHX_ SV* sv, const char* ptr);
@@ -674,7 +674,7 @@ VIRTUAL void	Perl_sv_setpvf_mg(pTHX_ SV *sv, const char* pat, ...);
 VIRTUAL void	Perl_sv_setiv_mg(pTHX_ SV *sv, IV i);
 VIRTUAL void	Perl_sv_setpviv_mg(pTHX_ SV *sv, IV iv);
 VIRTUAL void	Perl_sv_setuv_mg(pTHX_ SV *sv, UV u);
-VIRTUAL void	Perl_sv_setnv_mg(pTHX_ SV *sv, double num);
+VIRTUAL void	Perl_sv_setnv_mg(pTHX_ SV *sv, NV num);
 VIRTUAL void	Perl_sv_setpv_mg(pTHX_ SV *sv, const char *ptr);
 VIRTUAL void	Perl_sv_setpvn_mg(pTHX_ SV *sv, const char *ptr, STRLEN len);
 VIRTUAL void	Perl_sv_setsv_mg(pTHX_ SV *dstr, SV *sstr);
diff --git a/sv.c b/sv.c
index 282baf9259..e44c533bf3 100644
--- a/sv.c
+++ b/sv.c
@@ -435,12 +435,12 @@ S_more_xiv(pTHX)
 STATIC XPVNV*
 S_new_xnv(pTHX)
 {
-    double* xnv;
+    NV* xnv;
     LOCK_SV_MUTEX;
     if (!PL_xnv_root)
 	more_xnv();
     xnv = PL_xnv_root;
-    PL_xnv_root = *(double**)xnv;
+    PL_xnv_root = *(NV**)xnv;
     UNLOCK_SV_MUTEX;
     return (XPVNV*)((char*)xnv - STRUCT_OFFSET(XPVNV, xnv_nv));
 }
@@ -448,9 +448,9 @@ S_new_xnv(pTHX)
 STATIC void
 S_del_xnv(pTHX_ XPVNV *p)
 {
-    double* xnv = (double*)((char*)(p) + STRUCT_OFFSET(XPVNV, xnv_nv));
+    NV* xnv = (NV*)((char*)(p) + STRUCT_OFFSET(XPVNV, xnv_nv));
     LOCK_SV_MUTEX;
-    *(double**)xnv = PL_xnv_root;
+    *(NV**)xnv = PL_xnv_root;
     PL_xnv_root = xnv;
     UNLOCK_SV_MUTEX;
 }
@@ -458,17 +458,17 @@ S_del_xnv(pTHX_ XPVNV *p)
 STATIC void
 S_more_xnv(pTHX)
 {
-    register double* xnv;
-    register double* xnvend;
-    New(711, xnv, 1008/sizeof(double), double);
-    xnvend = &xnv[1008 / sizeof(double) - 1];
-    xnv += (sizeof(XPVIV) - 1) / sizeof(double) + 1; /* fudge by sizeof XPVIV */
+    register NV* xnv;
+    register NV* xnvend;
+    New(711, xnv, 1008/sizeof(NV), NV);
+    xnvend = &xnv[1008 / sizeof(NV) - 1];
+    xnv += (sizeof(XPVIV) - 1) / sizeof(NV) + 1; /* fudge by sizeof XPVIV */
     PL_xnv_root = xnv;
     while (xnv < xnvend) {
-	*(double**)xnv = (double*)(xnv + 1);
+	*(NV**)xnv = (NV*)(xnv + 1);
 	xnv++;
     }
-    *(double**)xnv = 0;
+    *(NV**)xnv = 0;
 }
 
 STATIC XRV*
@@ -631,7 +631,7 @@ Perl_sv_upgrade(pTHX_ register SV *sv, U32 mt)
     U32		cur;
     U32		len;
     IV		iv;
-    double	nv;
+    NV		nv;
     MAGIC*	magic;
     HV*		stash;
 
@@ -656,7 +656,7 @@ Perl_sv_upgrade(pTHX_ register SV *sv, U32 mt)
 	cur	= 0;
 	len	= 0;
 	iv	= SvIVX(sv);
-	nv	= (double)SvIVX(sv);
+	nv	= (NV)SvIVX(sv);
 	del_XIV(SvANY(sv));
 	magic	= 0;
 	stash	= 0;
@@ -683,7 +683,7 @@ Perl_sv_upgrade(pTHX_ register SV *sv, U32 mt)
 	cur	= 0;
 	len	= 0;
 	iv	= (IV)pv;
-	nv	= (double)(unsigned long)pv;
+	nv	= (NV)(unsigned long)pv;
 	del_XRV(SvANY(sv));
 	magic	= 0;
 	stash	= 0;
@@ -1017,7 +1017,7 @@ Perl_sv_setuv_mg(pTHX_ register SV *sv, UV u)
 }
 
 void
-Perl_sv_setnv(pTHX_ register SV *sv, double num)
+Perl_sv_setnv(pTHX_ register SV *sv, NV num)
 {
     SV_CHECK_THINKFIRST(sv);
     switch (SvTYPE(sv)) {
@@ -1049,7 +1049,7 @@ Perl_sv_setnv(pTHX_ register SV *sv, double num)
 }
 
 void
-Perl_sv_setnv_mg(pTHX_ register SV *sv, double num)
+Perl_sv_setnv_mg(pTHX_ register SV *sv, NV num)
 {
     sv_setnv(sv,num);
     SvSETMAGIC(sv);
@@ -1181,7 +1181,7 @@ Perl_sv_2iv(pTHX_ register SV *sv)
 	    sv_upgrade(sv, SVt_PVNV);
 
 	(void)SvIOK_on(sv);
-	if (SvNVX(sv) < (double)IV_MAX + 0.5)
+	if (SvNVX(sv) < (NV)IV_MAX + 0.5)
 	    SvIVX(sv) = I_V(SvNVX(sv));
 	else {
 	    SvUVX(sv) = U_V(SvNVX(sv));
@@ -1208,7 +1208,7 @@ Perl_sv_2iv(pTHX_ register SV *sv)
 	if (numtype & IS_NUMBER_NOT_IV) {
 	    /* May be not an integer.  Need to cache NV if we cache IV
 	     * - otherwise future conversion to NV will be wrong.  */
-	    double d;
+	    NV d;
 
 	    d = Atof(SvPVX(sv));
 
@@ -1218,9 +1218,14 @@ Perl_sv_2iv(pTHX_ register SV *sv)
 	    (void)SvNOK_on(sv);
 	    (void)SvIOK_on(sv);
 	    DEBUG_c(PerlIO_printf(Perl_debug_log,
-				  "0x%lx 2nv(%g)\n",(unsigned long)sv,
+#if defined(USE_LONG_DOUBLE)
+				  "0x%lx 2nv(%Lg)\n",
+#else
+				  "0x%lx 2nv(%g)\n",
+#endif
+				  (unsigned long)sv,
 				  SvNVX(sv)));
-	    if (SvNVX(sv) < (double)IV_MAX + 0.5)
+	    if (SvNVX(sv) < (NV)IV_MAX + 0.5)
 		SvIVX(sv) = I_V(SvNVX(sv));
 	    else {
 		SvUVX(sv) = U_V(SvNVX(sv));
@@ -1348,7 +1353,7 @@ Perl_sv_2uv(pTHX_ register SV *sv)
 	if (numtype & IS_NUMBER_NOT_IV) {
 	    /* May be not an integer.  Need to cache NV if we cache IV
 	     * - otherwise future conversion to NV will be wrong.  */
-	    double d;
+	    NV d;
 
 	    d = Atof(SvPVX(sv));	/* XXXX 64-bit? */
 
@@ -1358,7 +1363,12 @@ Perl_sv_2uv(pTHX_ register SV *sv)
 	    (void)SvNOK_on(sv);
 	    (void)SvIOK_on(sv);
 	    DEBUG_c(PerlIO_printf(Perl_debug_log,
-				  "0x%lx 2nv(%g)\n",(unsigned long)sv,
+#if defined(USE_LONG_DOUBLE)
+				  "0x%lx 2nv(%Lg)\n",
+#else
+				  "0x%lx 2nv(%g)\n",
+#endif
+				  (unsigned long)sv,
 				  SvNVX(sv)));
 	    if (SvNVX(sv) < -0.5) {
 		SvIVX(sv) = I_V(SvNVX(sv));
@@ -1420,7 +1430,7 @@ Perl_sv_2uv(pTHX_ register SV *sv)
     return SvIsUV(sv) ? SvUVX(sv) : (UV)SvIVX(sv);
 }
 
-double
+NV
 Perl_sv_2nv(pTHX_ register SV *sv)
 {
     if (!sv)
@@ -1437,9 +1447,9 @@ Perl_sv_2nv(pTHX_ register SV *sv)
 	}
 	if (SvIOKp(sv)) {
 	    if (SvIsUV(sv)) 
-		return (double)SvUVX(sv);
+		return (NV)SvUVX(sv);
 	    else
-		return (double)SvIVX(sv);
+		return (NV)SvIVX(sv);
 	}	
         if (!SvROK(sv)) {
 	    if (!(SvFLAGS(sv) & SVs_PADTMP)) {
@@ -1455,7 +1465,7 @@ Perl_sv_2nv(pTHX_ register SV *sv)
 	  SV* tmpstr;
 	  if (SvAMAGIC(sv) && (tmpstr=AMG_CALLun(sv,numer)))
 	      return SvNV(tmpstr);
-	  return (double)(unsigned long)SvRV(sv);
+	  return (NV)(unsigned long)SvRV(sv);
 	}
 	if (SvREADONLY(sv)) {
 	    dTHR;
@@ -1466,9 +1476,9 @@ Perl_sv_2nv(pTHX_ register SV *sv)
 	    }
 	    if (SvIOKp(sv)) {
 		if (SvIsUV(sv)) 
-		    return (double)SvUVX(sv);
+		    return (NV)SvUVX(sv);
 		else
-		    return (double)SvIVX(sv);
+		    return (NV)SvIVX(sv);
 	    }
 	    if (ckWARN(WARN_UNINITIALIZED))
 		Perl_warner(aTHX_ WARN_UNINITIALIZED, PL_warn_uninit);
@@ -1483,7 +1493,12 @@ Perl_sv_2nv(pTHX_ register SV *sv)
 	DEBUG_c({
 	    RESTORE_NUMERIC_STANDARD();
 	    PerlIO_printf(Perl_debug_log,
-			  "0x%lx num(%g)\n",(unsigned long)sv,SvNVX(sv));
+#if defined(USE_LONG_DOUBLE)
+			  "0x%lx num(%Lg)\n",
+#else
+			  "0x%lx num(%g)\n",
+#endif
+			  (unsigned long)sv,SvNVX(sv)));
 	    RESTORE_NUMERIC_LOCAL();
 	});
     }
@@ -1492,7 +1507,7 @@ Perl_sv_2nv(pTHX_ register SV *sv)
     if (SvIOKp(sv) &&
 	    (!SvPOKp(sv) || !strchr(SvPVX(sv),'.') || !looks_like_number(sv)))
     {
-	SvNVX(sv) = SvIsUV(sv) ? (double)SvUVX(sv) : (double)SvIVX(sv);
+	SvNVX(sv) = SvIsUV(sv) ? (NV)SvUVX(sv) : (NV)SvIVX(sv);
     }
     else if (SvPOKp(sv) && SvLEN(sv)) {
 	dTHR;
@@ -1513,7 +1528,12 @@ Perl_sv_2nv(pTHX_ register SV *sv)
     DEBUG_c({
 	RESTORE_NUMERIC_STANDARD();
 	PerlIO_printf(Perl_debug_log,
-		      "0x%lx 2nv(%g)\n",(unsigned long)sv,SvNVX(sv));
+#if defined(USE_LONG_DOUBLE)
+		      "0x%lx 2nv(%Lg)\n",
+#else
+		      "0x%lx 1nv(%g)\n",
+#endif
+		      (unsigned long)sv,SvNVX(sv)));
 	RESTORE_NUMERIC_LOCAL();
     });
     return SvNVX(sv);
@@ -1523,7 +1543,7 @@ STATIC IV
 S_asIV(pTHX_ SV *sv)
 {
     I32 numtype = looks_like_number(sv);
-    double d;
+    NV d;
 
     if (numtype & IS_NUMBER_TO_INT_BY_ATOL)
 	return atol(SvPVX(sv));		/* XXXX 64-bit? */
@@ -3754,13 +3774,13 @@ Perl_sv_inc(pTHX_ register SV *sv)
     if (flags & SVp_IOK) {
 	if (SvIsUV(sv)) {
 	    if (SvUVX(sv) == UV_MAX)
-		sv_setnv(sv, (double)UV_MAX + 1.0);
+		sv_setnv(sv, (NV)UV_MAX + 1.0);
 	    else
 		(void)SvIOK_only_UV(sv);
 		++SvUVX(sv);
 	} else {
 	    if (SvIVX(sv) == IV_MAX)
-		sv_setnv(sv, (double)IV_MAX + 1.0);
+		sv_setnv(sv, (NV)IV_MAX + 1.0);
 	    else {
 		(void)SvIOK_only(sv);
 		++SvIVX(sv);
@@ -3863,7 +3883,7 @@ Perl_sv_dec(pTHX_ register SV *sv)
 	    }	    
 	} else {
 	    if (SvIVX(sv) == IV_MIN)
-		sv_setnv(sv, (double)IV_MIN - 1.0);
+		sv_setnv(sv, (NV)IV_MIN - 1.0);
 	    else {
 		(void)SvIOK_only(sv);
 		--SvIVX(sv);
@@ -3981,7 +4001,7 @@ Perl_newSVpvf(pTHX_ const char* pat, ...)
 }
 
 SV *
-Perl_newSVnv(pTHX_ double n)
+Perl_newSVnv(pTHX_ NV n)
 {
     register SV *sv;
 
@@ -4273,7 +4293,7 @@ Perl_sv_uv(pTHX_ register SV *sv)
     return sv_2uv(sv);
 }
 
-double
+NV
 Perl_sv_nv(pTHX_ register SV *sv)
 {
     if (SvNOK(sv))
@@ -4449,7 +4469,7 @@ Perl_sv_setref_iv(pTHX_ SV *rv, const char *classname, IV iv)
 }
 
 SV*
-Perl_sv_setref_nv(pTHX_ SV *rv, const char *classname, double nv)
+Perl_sv_setref_nv(pTHX_ SV *rv, const char *classname, NV nv)
 {
     sv_setnv(newSVrv(rv,classname), nv);
     return rv;
@@ -4733,7 +4753,7 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 	unsigned base;
 	IV iv;
 	UV uv;
-	double nv;
+	NV nv;
 	STRLEN have;
 	STRLEN need;
 	STRLEN gap;
@@ -5051,7 +5071,7 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 	    /* This is evil, but floating point is even more evil */
 
 	    if (args)
-		nv = va_arg(*args, double);
+		nv = va_arg(*args, NV);
 	    else
 		nv = (svix < svmax) ? SvNVx(svargs[svix++]) : 0.0;
 
@@ -5078,6 +5098,9 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 	    eptr = ebuf + sizeof ebuf;
 	    *--eptr = '\0';
 	    *--eptr = c;
+#ifdef USE_LONG_DOUBLE
+	    *--eptr = 'L';
+#endif
 	    if (has_precis) {
 		base = precis;
 		do { *--eptr = '0' + (base % 10); } while (base /= 10);
diff --git a/sv.h b/sv.h
index 8eddc57a11..5787da383a 100644
--- a/sv.h
+++ b/sv.h
@@ -196,7 +196,7 @@ struct xpvnv {
     STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xiv_iv;		/* integer value or pv offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV    	xnv_nv;		/* numeric value, if any */
 };
 
 /* These structure must match the beginning of struct xpvhv in hv.h. */
@@ -205,7 +205,7 @@ struct xpvmg {
     STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xiv_iv;		/* integer value or pv offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV    	xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* linked list of magicalness */
     HV*		xmg_stash;	/* class package */
 };
@@ -215,7 +215,7 @@ struct xpvlv {
     STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xiv_iv;		/* integer value or pv offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV    	xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* linked list of magicalness */
     HV*		xmg_stash;	/* class package */
 
@@ -230,7 +230,7 @@ struct xpvgv {
     STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xiv_iv;		/* integer value or pv offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV		xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* linked list of magicalness */
     HV*		xmg_stash;	/* class package */
 
@@ -246,7 +246,7 @@ struct xpvbm {
     STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xiv_iv;		/* integer value or pv offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV		xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* linked list of magicalness */
     HV*		xmg_stash;	/* class package */
 
@@ -264,7 +264,7 @@ struct xpvfm {
     STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xiv_iv;		/* integer value or pv offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV		xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* linked list of magicalness */
     HV*		xmg_stash;	/* class package */
 
@@ -292,7 +292,7 @@ struct xpvio {
     STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
     STRLEN	xpv_len;	/* allocated size */
     IV		xiv_iv;		/* integer value or pv offset */
-    double	xnv_nv;		/* numeric value, if any */
+    NV		xnv_nv;		/* numeric value, if any */
     MAGIC*	xmg_magic;	/* linked list of magicalness */
     HV*		xmg_stash;	/* class package */
 
diff --git a/toke.c b/toke.c
index dd8742b02d..78491529ba 100644
--- a/toke.c
+++ b/toke.c
@@ -5953,7 +5953,7 @@ Perl_scan_num(pTHX_ char *start)
     register char *d;			/* destination in temp buffer */
     register char *e;			/* end of temp buffer */
     I32 tryiv;				/* used to see if it can be an int */
-    double value;			/* number read, as a double */
+    NV value;				/* number read, as a double */
     SV *sv;				/* place to put the converted number */
     I32 floatit;			/* boolean: int or float? */
     char *lastub = 0;			/* position of last underbar */
@@ -6169,7 +6169,7 @@ Perl_scan_num(pTHX_ char *start)
 	   conversion at all.
 	*/
 	tryiv = I_V(value);
-	if (!floatit && (double)tryiv == value)
+	if (!floatit && (NV)tryiv == value)
 	    sv_setiv(sv, tryiv);
 	else
 	    sv_setnv(sv, value);
diff --git a/universal.c b/universal.c
index 3e5547a58d..032a536e55 100644
--- a/universal.c
+++ b/universal.c
@@ -183,7 +183,7 @@ XS(XS_UNIVERSAL_VERSION)
     GV *gv;
     SV *sv;
     char *undef;
-    double req;
+    NV req;
 
     if(SvROK(ST(0))) {
         sv = (SV*)SvRV(ST(0));
diff --git a/util.c b/util.c
index 3655cefada..99415f0918 100644
--- a/util.c
+++ b/util.c
@@ -2630,7 +2630,7 @@ Perl_repeatcpy(pTHX_ register char *to, register const char *from, I32 len, regi
 }
 
 U32
-Perl_cast_ulong(pTHX_ double f)
+Perl_cast_ulong(pTHX_ NV f)
 {
     long along;
 
@@ -2667,7 +2667,7 @@ Perl_cast_ulong(pTHX_ double f)
 #endif
 
 I32
-Perl_cast_i32(pTHX_ double f)
+Perl_cast_i32(pTHX_ NV f)
 {
     if (f >= I32_MAX)
 	return (I32) I32_MAX;
@@ -2677,12 +2677,12 @@ Perl_cast_i32(pTHX_ double f)
 }
 
 IV
-Perl_cast_iv(pTHX_ double f)
+Perl_cast_iv(pTHX_ NV f)
 {
     if (f >= IV_MAX) {
 	UV uv;
 	
-	if (f >= (double)UV_MAX)
+	if (f >= (NV)UV_MAX)
 	    return (IV) UV_MAX;	
 	uv = (UV) f;
 	return (IV)uv;
@@ -2693,7 +2693,7 @@ Perl_cast_iv(pTHX_ double f)
 }
 
 UV
-Perl_cast_uv(pTHX_ double f)
+Perl_cast_uv(pTHX_ NV f)
 {
     if (f >= MY_UV_MAX)
 	return (UV) MY_UV_MAX;
@@ -3303,7 +3303,7 @@ Perl_new_struct_thread(pTHX_ struct perl_thread *t)
  * So it is in perl for (say) POSIX to use. 
  * Needed for SunOS with Sun's 'acc' for example.
  */
-double 
+NV 
 Perl_huge(void)
 {
  return HUGE_VAL;
@@ -3506,22 +3506,23 @@ Perl_my_fflush_all(pTHX)
 #endif
 }
 
-double
+NV
 Perl_my_atof(pTHX_ const char* s) {
 #ifdef USE_LOCALE_NUMERIC
     if ((PL_hints & HINT_LOCALE) && PL_numeric_local) {
-	double x, y;
+	NV x, y;
 
-	x = atof(s);
+	x = Perl_atof(s);
 	SET_NUMERIC_STANDARD();
-	y = atof(s);
+	y = Perl_atof(s);
 	SET_NUMERIC_LOCAL();
 	if ((y < 0.0 && y < x) || (y > 0.0 && y > x))
 	    return y;
 	return x;
-    } else
-	return atof(s);
+    }
+    else
+	return Perl_atof(s);
 #else
-    return atof(s);
+    return Perl_atof(s);
 #endif
 }