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Q60429: Using the C Emulator Library with an Assembly Program

Article: Q60429
Product(s): See article
Version(s): 5.10 5.10a | 5.10 5.10a
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | | mspl13_masm
Last Modified: 12-JUN-1990

An Assembler module may use a C emulator library if the assembler
module is called by a main C module. The C emulator library must be
used during the linking of the assembler and C modules.

Linking with the emulator library ensures that the assembler will have
floating-point math support with or without a a math coprocessor.

The math functions in the C run-time library require floating-point
support to perform calculations with real numbers. This support can be
provided by the floating-point emulator libraries that accompany your
compiler software or by an 8087 or 80287 coprocessor.

The assembler module -- if run as a stand-alone module, without a math
coprocessor, and linked to an emulator library -- generates emulator
interrupts for floating-point math code, but will not run because the
interrupts will not be initialized. The C start-up code is necessary
to initialize the interrupts. If you want to run the assembler module
as stand-alone, you must write your own emulator library.

With C, /FPi is the default switch. This switch selects the emulator
math package and generates inline floating-point instructions.

   CL /c calling.c

The assembler module is assembled with the following command, where
(by default) code is generated for a math coprocessor (if
floating-point instructions are used)

   MASM /E called.asm

where CALLING.C and CALLED.ASM are the calling and called modules,
respectively.

While programming in the QuickC environment, /FPi must be specified in
the Global Custom Flags field of the Assembler Flags Dialog box
(reached through the Options menu). This allows the C emulator library
to be used for all the assembler modules.

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