Converting floating point numbers to strings

[PatrickDS]

I am learning assembler for a few days now (I usually program with VB.net or Java)
and wanted to do some basic calculations with floating-point numbers to understand the logic of the FPU.

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finit                       
fld    dword ptr [value1]
fld    dword ptr [value2]
fadd                             
fstp   dword ptr [sum]


My problem is that I am not sure how to convert my result in [sum] to the screen.

With unsigned integers I usually use:

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print str$(sum)


But that doesn't work! I know that this is basic stuff, but I'm really frustrated. 

I hope that you can help me. Thank you already in advance. 

[hutch--]

I am working in 64 bit these days but see if one of the MSVCRT functions like "_sprintf" will work for you. In 32 bit MASM32 there is the C runtime function "crt_sprintf". Check the Microsoft documentation to see if it works.

[HSE]

Welcome to the forum!

If you have declared:

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value1 real4 0.0
value2 real4  0.0
sum real4 0.0 you can use:

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print real4$(sum)
Same thing with real8:

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.data
value1 real8 2.0
value2 real8  5.0
sum real8 0.0
.code
finit                       
fld    value1
fld    value2
fadd                             
fstp   sum
print real8$(sum)


You also can use FPU for integers width Fild,,fistp and str$.

[PatrickDS]

Thanks, that helped very much. 

Welcome to the forum!

If you have declared:

Code Select Expand

value1 real4 0.0
value2 real4  0.0
sum real4 0.0 you can use:

Code Select Expand

print real4$(sum)
Same thing with real8:

Code Select Expand

.data
value1 real8 2.0
value2 real8  5.0
sum real8 0.0
.code
finit                       
fld    value1
fld    value2
fadd                             
fstp   sum
print real8$(sum)


You also can use FPU for integers width Fild,,fistp and str$.

[raymond]

Warm welcome to this forum.

wanted to do some basic calculations with floating-point numbers to understand the logic of the FPU

Did you have a look at this (which is really a part of this site):  http://www.ray.masmcode.com/fpu.html

[PatrickDS]

Yeah, that's the page where I learned the basic mnemonics for the FPU. 

[raymond]

You can also use the available library to perform a number of functions, and to also learn how those can be coded to avoid the overhead (and improve speed); the algo for all the functions is provided.