Uses a PCH file if it exists, creates a PCH file otherwise.
This option is deprecated.
Support for Precompiled Header (PCH) files is deprecated from ARM Compiler 5.05 onwards on all platforms. Note that ARM Compiler on Windows 8 never supported PCH files.
When the option
--pch is specified, the compiler searches for a PCH file
with the name
filename.* is the name of the primary source
file. The compiler uses the PCH file
it exists, and creates a PCH file named
in the same directory as the primary source file otherwise.
This option has no effect if you include either the option
--use_pch= or the option
--create_pch= on the same command line.