Using and Porting GNU CC

3.14.13: Intel 960 Options

These `-m' options are defined for the Intel 960 implementations:

-mcpu type

Assume the defaults for the machine type cpu type for some of the other options, including instruction scheduling, floating point support, and addressing modes. The choices for cpu type are `ka', `kb', `mc', `ca', `cf', `sa', and `sb'. The default is `kb'.

-mnumerics

-msoft-float

The `-mnumerics' option indicates that the processor does support floating-point instructions. The `-msoft-float' option indicates that floating-point support should not be assumed.

-mleaf-procedures

-mno-leaf-procedures

Do (or do not) attempt to alter leaf procedures to be callable with the bal instruction as well as call. This will result in more efficient code for explicit calls when the bal instruction can be substituted by the assembler or linker, but less efficient code in other cases, such as calls via function pointers, or using a linker that doesn't support this optimization.

-mtail-call

-mno-tail-call

Do (or do not) make additional attempts (beyond those of the machine-independent portions of the compiler) to optimize tail-recursive calls into branches. You may not want to do this because the detection of cases where this is not valid is not totally complete. The default is `-mno-tail-call'.

-mcomplex-addr

-mno-complex-addr

Assume (or do not assume) that the use of a complex addressing mode is a win on this implementation of the i960. Complex addressing modes may not be worthwhile on the K-series, but they definitely are on the C-series. The default is currently `-mcomplex-addr' for all processors except the CB and CC.

-mcode-align

-mno-code-align

Align code to 8-byte boundaries for faster fetching (or don't bother). Currently turned on by default for C-series implementations only.

-mic-compat

-mic2.0-compat

-mic3.0-compat

Enable compatibility with iC960 v2.0 or v3.0.

-masm-compat

-mintel-asm

Enable compatibility with the iC960 assembler.

-mstrict-align

-mno-strict-align

Do not permit (do permit) unaligned accesses.

-mold-align

Enable structure-alignment compatibility with Intel's gcc release version 1.3 (based on gcc 1.37). Currently this is buggy in that `#pragma align 1' is always assumed as well, and cannot be turned off.