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Re: Immediate Problems at the Reload Phase of GCC
- To: pmw at uk dot research dot att dot com (Paul Webster)
- Subject: Re: Immediate Problems at the Reload Phase of GCC
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Tue, 29 Feb 2000 11:25:30 -0700
- cc: gcc-help at gcc dot gnu dot org
- Reply-To: law at cygnus dot com
In message <200002291823.SAA12545@rocoto>you write:
>
> This question is regarding gcc version 2.95.2.
>
> I am working with an instruction set that contains an immediate and registe
> r
> based compare for equality instruction. The immediate version can take a 16
> -bit
> signed value and a register. The register version takes two registers.
>
> Currently, I have a define_insn for the register comparison. I also have a
> define_insn for the immediate variation, constrained to only accept 16-bit
> signed values.
Use a single define_insn with multiple alternative constraints.
> I guess the solution is to block this propogation in the reload phase?
No. That would just paper over the problem.
jeff