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Re: INSN_CODE_NUMBER of INT_MAX
- To: jh at suse dot cz (Jan Hubicka)
- Subject: Re: INSN_CODE_NUMBER of INT_MAX
- From: Joern Rennecke <amylaar at redhat dot com>
- Date: Thu, 26 Jul 2001 21:41:36 +0100 (BST)
- Cc: amylaar at redhat dot com (Joern Rennecke), jh at suse dot cz (Jan Hubicka),rth at redhat dot com (Richard Henderson),kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner), gcc at gcc dot gnu dot org
> Interesting. How does the register allocation use it?
If the value is a constant, or the sum of the stack/frame pointer and a
constant, that value can be used instead of the register.
And if a register is only set once, the value can also in some places
be replaced into the users.
Also some register tying makes use of REG_EQUAL notes.
just search in local-alloc.c for REG_EQUAL.
Moreover, regmove makes use of REG_EQUAL notes.