DOCUMENT:Q59127  04-MAY-2001  [masm]
TITLE   :Testing Math Coprocessor Instructions FLD FADD FSTP FST
PRODUCT :Microsoft Macro Assembler
PROD/VER::5.1
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft Macro Assembler (MASM), version 5.1 
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SUMMARY
=======

The following code was used to view coprocessor instructions on an 80386 machine
with an 80387 coprocessor. It is a combination of the examples on Pages 384 and
385 of "Microsoft Macro Assembler 5.1 for the MS-DOS Operating System
Programmer's Guide."

                  .model small
                  .386
                  .387
                  .stack 100h
                  .data
         m1       dd   1.0
         m2       dd   2.0
                  .code
         start    proc
                  mov ax, @data ;load address of segment
                  mov ds,  ax   ;     register
                  fld   m1      ;push m1 into st(0)
                  fld   m2      ;push m2 into st(0)
                  fadd  m1      ;add m2 to st(0)
                  fstp  m1      ;pop st(0) into m1
                  fst   m2      ;copy st(0) into m2

                  fld1          ;push 1 into st(0)
                  fldpi         ;push pi into st(0)
                  fadd          ;add st(0) and st(1)
                                ;and pop, place result in st(0)
         start    endp
                  end  start

While assembling the above code, the .386 and .387 directives must be placed
below the .model directive to generate 16-bit segments. If placed above the
.model directive, 32-bit segments will be generated and will produce erroneous
results, as 32-bit segments cannot be run under DOS.

While running the code through CodeView, the number 7 entered in the dialog box
displays a dump of the present status of the chip.

Additional query words: 5.10

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Keywords          :  
Technology        : kbMASMsearch kbAudDeveloper kbMASM510
Version           : :5.1

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