Red Hat ENTERPRISE LINUX 4 Manual page 104

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, while
-mpowerpc
defaults to
-maix32
-mxl-call
-mno-xl-call
On AIX, pass floating-point arguments to prototyped functions beyond the register save area
(RSA) on the stack in addition to argument FPRs. The AIX calling convention was extended but
not initially documented to handle an obscure K&R C case of calling a function that takes the
address of its arguments with fewer arguments than declared. AIX XL compilers access floating
point arguments which do not fit in the RSA from the stack when a subroutine is compiled with-
out optimization. Because always storing floating-point arguments on the stack is inefficient and
rarely needed, this option is not enabled by default and only is necessary when calling subrou-
tines compiled by AIX XL compilers without optimization.
-mpe
Support IBM RS/6000 SP Parallel Environment (PE). Link an application written to use message
passing with special startup code to enable the application to run. The system must have PE
installed in the standard location (
with the
-specs=
does not support threads, so the
-malign-natural
-malign-power
On Darwin and 64-bit PowerPC GNU/Linux, the option
defined alignment of larger types, such as floating-point doubles, on their natural size-based
boundary. The option
rules. GCC defaults to the standard alignment defined in the ABI.
-msoft-float
-mhard-float
Generate code that does not use (uses) the floating-point register set. Software floating point
emulation is provided if you use the
linking.
-mmultiple
-mno-multiple
Generate code that uses (does not use) the load multiple word instructions and the store multiple
word instructions. These instructions are generated by default on POWER systems, and not gen-
erated on PowerPC systems. Do not use
those instructions do not work when the processor is in little endian mode. The exceptions are
PPC740 and PPC750 which permit the instructions usage in little endian mode.
-mstring
-mno-string
Generate code that uses (does not use) the load string instructions and the store string word
instructions to save multiple registers and do small block moves. These instructions are generated
by default on POWER systems, and not generated on PowerPC systems. Do not use
on little endian PowerPC systems, since those instructions do not work when the processor is in
little endian mode. The exceptions are PPC740 and PPC750 which permit the instructions usage
in little endian mode.
disables the 64-bit ABI and implies
-maix32
.
/usr/lpp/ppe.poe/
option to specify the appropriate directory location. The Parallel Environment
option and the
-mpe
-malign-power
-msoft-float
Chapter 4. GCC Command Options
), or the
-pthread
-malign-natural
instructs GCC to follow the ABI-specified alignment
option, and pass the option to GCC when
on little endian PowerPC systems, since
-mmultiple
-mno-powerpc64
file must be overridden
specs
option are incompatible.
overrides the ABI-
. GCC
-mstring