Hi Richard, 在 2022/11/29 2:46, Richard Biener 写道: > Anyhow - my question still stands - what's the fallback for the callers > that do not check for failure? How are we sure we're not running into > these when relaxing the requirement that a MODE_CC prepare_cmp_insn > must not fail?
I examed the code and found that currently callers should be fine with returning a NULL_RTX for MODE_CC processing. The prepare_cmp_insn is called by following callers. 1 gen_cond_trap which doesn't uses MODE_CC 2 prepare_cmp_insn itself where is after MODE_CC processing, so it never hits MODE_CC 3 emit_cmp_and_jump_insns which doesn't uses MODE_CC 4 emit_conditional_move which checks the output is null or not 5 emit_conditional_add which checks the output is null or not Not sure if I missed something. Looking forward to your advice. Thanks a lot Gui Haochen
