Hi -- I've run into a problem with the MicroBlaze backend where it is not recognizing a return pattern. I'm trying to modify the back end to use the 'simple_return' pattern, rather than 'return', since MicroBlaze has exactly what the documentation describes: a no-frills return instruction which does nothing more than branch back to the caller.
When I define only 'simple_return', there are undefined references in function.c for emit_return_into_block() and emit_use_return_register_into_block(), since these are defined when HAVE_return is defined. MIPS has a similar call/return model, with a trivial return instruction. mips.md defines expanders for both 'return' and 'simple_return' and identical insn's for both which generate the return jump. ARM also has a simple return, but the back end defines 'return' and does not define 'simple_return'. My guess is that the #ifdef HAVE_return in function.c which surrounds the undefined functions should be removed. What is the correct model for the back end? Define only 'return' like ARM, define both 'return' and 'simple_return' like MIPS, or define only 'simple_return' like I tried to do? -- Michael Eager ea...@eagercon.com 1960 Park Blvd., Palo Alto, CA 94306 650-325-8077
