#include <stdio.h>

cmpFsFd( float s, double d ) {
	float tmp = (float)d;
	return s == tmp ? 1 : 0;
}

int main(void) {
   double nv = 2.0 / 3;
   float foo = 2.0 / 3;

   if( foo == nv ) printf("True ");
   else printf("False ");

   if( cmpFsFd( foo, nv )) printf("True\n");
   else printf("False\n");

   return 0;
}

##</code><code>##

[19:48:23.40} C:\test>cl float.c /Fefloatv8.exe
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86
Copyright (C) Microsoft Corporation.  All rights reserved.

float.c
Microsoft (R) Incremental Linker Version 9.00.30729.01
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:floatv8.exe
float.obj

[19:49:59.60} C:\test>floatv8
False True

----------------------------------------------------
c:\test>cl float.c /Fefloatv6.exe
Microsoft (R) 32-bit C/C++ Standard Compiler Version 13.00.9466 for 80x86
Copyright (C) Microsoft Corporation 1984-2001. All rights reserved.

float.c
Microsoft (R) Incremental Linker Version 7.00.9466
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:floatv6.exe
float.obj

c:\test>floatv6
False True

##</code><code>##

; 15   :    if( foo == (float)nv ) printf("True\n");

	fld	QWORD PTR _nv$[ebp]  ## Load nv onto FPU stack
	fstp	DWORD PTR tv79[ebp]  ## store (and pop) it into a 32-bit (float) temporary
	fld	DWORD PTR tv79[ebp]  ## load it back onto the FPU stack
	fld	DWORD PTR _foo$[ebp] ## load foo onto the FPU stack
	fucompp                      ## do the comparison
	fnstsw	ax                   ## get the FPU status word into AX
	test	ah, 68		     ## 00000044H (Check for equality?)
	jp	SHORT $LN2@main      ## Jump 
	push	OFFSET $SG2485       ## or not ...
	call	_printf


##</code><code>##

; 15   :    if( foo == (float)nv ) printf("True\n");

	fld	QWORD PTR _nv$[ebp]    ## Load nv to FPU stack
	fst	DWORD PTR tv78[ebp]    ## Store it to a temporary but...
        *** NEVER LOADS IT BACK *** 
        *** And does the comparison between the FPU register and the memory image of foo ***
	fcomp	DWORD PTR _foo$[ebp]
	fnstsw	ax
	test	ah, 68					; 00000044H
	jp	SHORT $L800
	push	OFFSET FLAT:$SG801
	call	_printf