Q50523: Floating-Point Initialization Occurs at Link Time

Article: Q50523
Product(s): See article
Version(s): 5.10   | 5.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | S_QuickC S_QuickASM | mspl13_c
Last Modified: 21-MAR-1990

Floating-point initialization occurs at link time. If the compiler has
generated any floating-point instructions, it lists an external
symbol. When the linker sees the external symbol, it brings in the
necessary segment.

In C 5.10, the external symbol is __fltused. The linker brings in a
module that has a common CDATA segment that defines the correct values
of fpmath, fpdata, and fpsignal. If this module is not brought in, the
CDATA segment defaults to all zeros. This is why CDATA is defined as
common and not public.

This process causes the floating-point support to be linked only if
floating point is used.