Using the GNU Compiler Collection (GCC): HPPA Options

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3.18.17 HPPA Options

These ‘-m’ options are defined for the HPPA family of computers:

-march=architecture-type

Generate code for the specified architecture. The choices for architecture-type are ‘1.0’ for PA 1.0, ‘1.1’ for PA 1.1, and ‘2.0’ for PA 2.0 processors. Refer to /usr/lib/sched.models on an HP-UX system to determine the proper architecture option for your machine. Code compiled for lower numbered architectures runs on higher numbered architectures, but not the other way around.

-mpa-risc-1-0

-mpa-risc-1-1

-mpa-risc-2-0

Synonyms for -march=1.0, -march=1.1, and -march=2.0 respectively.

-mcaller-copies

The caller copies function arguments passed by hidden reference. This option should be used with care as it is not compatible with the default 32-bit runtime. However, only aggregates larger than eight bytes are passed by hidden reference and the option provides better compatibility with OpenMP.

-mjump-in-delay

This option is ignored and provided for compatibility purposes only.

-mdisable-fpregs

Prevent floating-point registers from being used in any manner. This is necessary for compiling kernels that perform lazy context switching of floating-point registers. If you use this option and attempt to perform floating-point operations, the compiler aborts.

-mdisable-indexing

Prevent the compiler from using indexing address modes. This avoids some rather obscure problems when compiling MIG generated code under MACH.

-mno-space-regs

Generate code that assumes the target has no space registers. This allows GCC to generate faster indirect calls and use unscaled index address modes.

Such code is suitable for level 0 PA systems and kernels.

-mfast-indirect-calls

Generate code that assumes calls never cross space boundaries. This allows GCC to emit code that performs faster indirect calls.

This option does not work in the presence of shared libraries or nested functions.

-mfixed-range=register-range

Generate code treating the given register range as fixed registers. A fixed register is one that the register allocator cannot use. This is useful when compiling kernel code. A register range is specified as two registers separated by a dash. Multiple register ranges can be specified separated by a comma.

-mlong-load-store

Generate 3-instruction load and store sequences as sometimes required by the HP-UX 10 linker. This is equivalent to the ‘+k’ option to the HP compilers.

-mportable-runtime

Use the portable calling conventions proposed by HP for ELF systems.

-mgas

Enable the use of assembler directives only GAS understands.

-mschedule=cpu-type

Schedule code according to the constraints for the machine type cpu-type. The choices for cpu-type are ‘700’ ‘7100’, ‘7100LC’, ‘7200’, ‘7300’ and ‘8000’. Refer to /usr/lib/sched.models on an HP-UX system to determine the proper scheduling option for your machine. The default scheduling is ‘8000’.

-mlinker-opt

Enable the optimization pass in the HP-UX linker. Note this makes symbolic debugging impossible. It also triggers a bug in the HP-UX 8 and HP-UX 9 linkers in which they give bogus error messages when linking some programs.

-msoft-float

Generate output containing library calls for floating point. Warning: the requisite libraries are not available for all HPPA targets. Normally the facilities of the machine’s usual C compiler are used, but this cannot be done directly in cross-compilation. You must make your own arrangements to provide suitable library functions for cross-compilation.

-msoft-float changes the calling convention in the output file; therefore, it is only useful if you compile all of a program with this option. In particular, you need to compile libgcc.a, the library that comes with GCC, with -msoft-float in order for this to work.

-msio

Generate the predefine, _SIO, for server IO. The default is -mwsio. This generates the predefines, __hp9000s700, __hp9000s700__ and _WSIO, for workstation IO. These options are available under HP-UX and HI-UX.

-mgnu-ld

Use options specific to GNU ld. This passes -shared to ld when building a shared library. It is the default when GCC is configured, explicitly or implicitly, with the GNU linker. This option does not affect which ld is called; it only changes what parameters are passed to that ld. The ld that is called is determined by the --with-ld configure option, GCC’s program search path, and finally by the user’s PATH. The linker used by GCC can be printed using ‘which `gcc -print-prog-name=ld`’. This option is only available on the 64-bit HP-UX GCC, i.e. configured with ‘hppa*64*-*-hpux*’.

-mhp-ld

Use options specific to HP ld. This passes -b to ld when building a shared library and passes +Accept TypeMismatch to ld on all links. It is the default when GCC is configured, explicitly or implicitly, with the HP linker. This option does not affect which ld is called; it only changes what parameters are passed to that ld. The ld that is called is determined by the --with-ld configure option, GCC’s program search path, and finally by the user’s PATH. The linker used by GCC can be printed using ‘which `gcc -print-prog-name=ld`’. This option is only available on the 64-bit HP-UX GCC, i.e. configured with ‘hppa*64*-*-hpux*’.

-mlong-calls

Generate code that uses long call sequences. This ensures that a call is always able to reach linker generated stubs. The default is to generate long calls only when the distance from the call site to the beginning of the function or translation unit, as the case may be, exceeds a predefined limit set by the branch type being used. The limits for normal calls are 7,600,000 and 240,000 bytes, respectively for the PA 2.0 and PA 1.X architectures. Sibcalls are always limited at 240,000 bytes.

Distances are measured from the beginning of functions when using the -ffunction-sections option, or when using the -mgas and -mno-portable-runtime options together under HP-UX with the SOM linker.

It is normally not desirable to use this option as it degrades performance. However, it may be useful in large applications, particularly when partial linking is used to build the application.

The types of long calls used depends on the capabilities of the assembler and linker, and the type of code being generated. The impact on systems that support long absolute calls, and long pic symbol-difference or pc-relative calls should be relatively small. However, an indirect call is used on 32-bit ELF systems in pic code and it is quite long.

-munix=unix-std

Generate compiler predefines and select a startfile for the specified UNIX standard. The choices for unix-std are ‘93’, ‘95’ and ‘98’. ‘93’ is supported on all HP-UX versions. ‘95’ is available on HP-UX 10.10 and later. ‘98’ is available on HP-UX 11.11 and later. The default values are ‘93’ for HP-UX 10.00, ‘95’ for HP-UX 10.10 though to 11.00, and ‘98’ for HP-UX 11.11 and later.

-munix=93 provides the same predefines as GCC 3.3 and 3.4. -munix=95 provides additional predefines for XOPEN_UNIX and _XOPEN_SOURCE_EXTENDED, and the startfile unix95.o. -munix=98 provides additional predefines for _XOPEN_UNIX, _XOPEN_SOURCE_EXTENDED, _INCLUDE__STDC_A1_SOURCE and _INCLUDE_XOPEN_SOURCE_500, and the startfile unix98.o.

It is important to note that this option changes the interfaces for various library routines. It also affects the operational behavior of the C library. Thus, extreme care is needed in using this option.

Library code that is intended to operate with more than one UNIX standard must test, set and restore the variable __xpg4_extended_mask as appropriate. Most GNU software doesn’t provide this capability.

-nolibdld

Suppress the generation of link options to search libdld.sl when the -static option is specified on HP-UX 10 and later.

-static

The HP-UX implementation of setlocale in libc has a dependency on libdld.sl. There isn’t an archive version of libdld.sl. Thus, when the -static option is specified, special link options are needed to resolve this dependency.

On HP-UX 10 and later, the GCC driver adds the necessary options to link with libdld.sl when the -static option is specified. This causes the resulting binary to be dynamic. On the 64-bit port, the linkers generate dynamic binaries by default in any case. The -nolibdld option can be used to prevent the GCC driver from adding these link options.

-threads

Add support for multithreading with the dce thread library under HP-UX. This option sets flags for both the preprocessor and linker.

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