Most recent round of nvcc's interactions with SvNV and friends

console-output.txt

SV = NV(0x89ed504) at 0x89d2308
  REFCNT = 1
  FLAGS = (NOK,READONLY,pNOK)
  NV = 5
---------------------
The string interpretation of the floating point is 0.000000
  -> when cast to a float, we have 0.000000; to a double, 0.000000
  -> when directly printed as %f: 0.000000
  -> real_constant is 5.000000
---------------------
SV = PVNV(0x8a50fc0) at 0x89d2308
  REFCNT = 1
  FLAGS = (NOK,POK,READONLY,pNOK,pPOK)
  IV = 0
  NV = 5
  PV = 0x89dcdf0 "5"\0
  CUR = 1
  LEN = 36
---------------------

SV = NV(0x89ed50c) at 0x89d2298
  REFCNT = 1
  FLAGS = (NOK,READONLY,pNOK)
  NV = 0.25
---------------------
The string interpretation of the floating point is 0.000000
  -> when cast to a float, we have 0.000000; to a double, 0.000000
  -> when directly printed as %f: 0.000000
  -> real_constant is 0.250000
---------------------
SV = PVNV(0x8a50fd4) at 0x89d2298
  REFCNT = 1
  FLAGS = (NOK,POK,READONLY,pNOK,pPOK)
  IV = 0
  NV = 0.25
  PV = 0x89d7b40 "0.25"\0
  CUR = 4
  LEN = 36
---------------------

SV = NV(0x89ed51c) at 0x89d21b8
  REFCNT = 1
  FLAGS = (NOK,READONLY,pNOK)
  NV = -0.14
---------------------
The string interpretation of the floating point is 0.000000
  -> when cast to a float, we have 0.000000; to a double, 0.000000
  -> when directly printed as %f: 0.000000
  -> real_constant is -0.140000
---------------------
SV = PVNV(0x8a50fe8) at 0x89d21b8
  REFCNT = 1
  FLAGS = (NOK,POK,READONLY,pNOK,pPOK)
  IV = 0
  NV = -0.14
  PV = 0x89dbed0 "-0.14"\0
  CUR = 5
  LEN = 36
---------------------

test-xs.pl

use strict;
use warnings;
use ToTest;

ToTest::check_float_stuff(5.0);
ToTest::check_float_stuff(0.25);
ToTest::check_float_stuff(-0.14);

ToTest.pm

package ToTest;
 
use 5.008_008;
use strict;
use warnings;
 
our $VERSION = '0.04';
 
require XSLoader;
XSLoader::load('ToTest', $VERSION);

ToTest.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

/*#include "ppport.h"*/

MODULE = ToTest		PACKAGE = ToTest

void
check_float_stuff(SV * constant_SV)
 PROTOTYPE: $
 PREINIT:
	float real_const, constant;
	double constant_d;
 CODE:
	sv_dump(constant_SV);
	real_const = atof(SvPV_nolen(constant_SV));
	printf("---------------------\n");
	printf("The string interpretation of the floating point is %f\n", SvNVX(constant_SV));
	// printf("The string interpretation of the floating point is %f\n", SvNV_nomg(constant_SV));
	//printf("The string interpretation of constant_SV is %s; the floating point is %f\n",
	//	SvPV_nolen(constant_SV), SvNV_nomg(constant_SV));
	constant = (float) SvNV_nomg(constant_SV);
	constant_d = SvNV_nomg(constant_SV);
	printf("  -> when cast to a float, we have %f; to a double, %f\n", constant, constant_d);
	printf("  -> when directly printed as %%f: %f\n", SvNV(constant_SV));
	printf("  -> real_constant is %f\n", real_const);
	printf("---------------------\n");
	sv_dump(constant_SV);
	printf("---------------------\n\n");