Intel i960 - Pragma Compress

i960 Processor Compiler User's Guide
7-30
7
4. The last two instructions in the dispatcher are:
callx 80(r10)
ret
5. callx is a call to a decompressed secondary function. Set a
breakpoint on
callx and step into the function.
6. Continue debugging the function on the machine level.
#pragma compress
#pragma compress [ [(] function [,...] [)] ]
#pragma nocompress [ [(]
function [,...] [)] ]
function specifies the function for the compiler to
compress or not compress.
Controls the replacement of RISC instructions with CISC instructions.
Default
The compiler does not usually generate compressed (microcoded CISC)
instructions, but the code produced may still use complex addressing
modes for memory accesses. The compiler may generate single-line
instructions (e.g.,
cmpoble) for two-line compare-and-branch instructions
(e.g.,
cmpo and ble) but does not always do so.
Discussion
The
compress and nocompress pragmas control the replacement of RISC
instructions with CISC instructions.
If code size is of primary importance, use
compress to replace RISC
instructions with CISC instructions, thereby compressing the code size.
Generated instructions use complex addressing modes. When
compress
is in effect, the compiler also generates single-line instructions for
compare-and-branch instructions when possible.
Use
nocompress to use RISC instructions, increasing the number of
instructions but producing code that may run faster when instructions are
found in the instruction cache. Generated instructions do not use complex