I have a toy backend based on the moxie backend as a template. During its development I found some oddities in the moxie backend that may be bugs.
1. The REGNO_OK_FOR_INDEX_P(NUM) macro in moxie.h is: #define REGNO_OK_FOR_INDEX_P(NUM) MOXIE_FP Since MOXIE_FP is 0, this returns false for every register. Should the body be a literal 0, or some comparison between NUM and MOXIE_FP? 2. I see no actual use of MOXIE_PC or the SPECIAL_REGS register class. Could they be deleted (with adjustments for decrementing MOXIE_CC)? 3. moxie_compute_frame () doesn't take !fixed_regs[regno] into account, which the related loops in moxie_expand_prologue () and moxie_expand_epilogue () do. Bug? There are also some minor nits: 4. The comment above `size_for_adjusting_sp' states it's used in expand_epilogue(), which it isn't. 5. The "Compute this since .." comment in moxie_initial_elimination_offset () should probably refer to callee_saved_reg_size not local_vars_size, to match the code. 6. There are two idential definitions of TRULY_NOOP_TRUNCATION(op,ip) in moxie.h. The first one looks misplaced and should probably be deleted. /Mikael