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Back end question.
- From: "Dmitry" <mittie at ukr dot net>
- To: gcc-help at gcc dot gnu dot org
- Date: Thu, 28 Apr 2011 16:48:44 +0300
- Subject: Back end question.
Hello.
I'm currently writing a GCC back end for a custom architecture. And I have a RTL related question. If I am, for example, writing an implementation for "movhi" insn, and depending on a register class of the destination operand it could include a condition code register change. How can I write a right implementation for such case? If I use "define_expand" RTX destination registers are not allocated yet so they could be any pseudo registers. So I can not determine the class of that registers during RTL generation phase. Should I use "define_split" additionally to analyze operand's register class after reload phase? Or maybe there's other way?
Really appreciate someone's help.
Dmitry.