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Re: [PATCH] -fpic problems on PPC, a different approach
- To: law at cygnus dot com
- Subject: Re: [PATCH] -fpic problems on PPC, a different approach
- From: Geoff Keating <geoffk at ozemail dot com dot au>
- Date: Tue, 8 Jun 1999 19:06:09 +1000
- CC: Franz dot Sirl-kernel at lauterbach dot com, egcs-patches at egcs dot cygnus dot com
- References: <5622.928805210@upchuck.cygnus.com>
> cc: Geoff Keating <geoffk@ozemail.com.au>, egcs-patches@egcs.cygnus.com
> Reply-To: law@cygnus.com
> Date: Mon, 07 Jun 1999 19:26:50 -0600
> From: Jeffrey A Law <law@cygnus.com>
...
> I would have recommended against checking for CONST_DOUBLEs explicitly;
> instead
> I would have suggested either using LEGITIMATE_PIC_OPERAND_P to determine
> what REG_EQUALs could potentially cause you problems later.
>
> This makes me wonder about another way to fix this, if indeed it can only
> happen when we have REG_EQUIVs that reference CONST_DOUBLEs.
To be precise, it happens when something is spilled to memory by
reload. This most commonly happens when the 'something' is a
CONST_DOUBLE, but I don't think it's the only way.
> You can force reload to ignore those constants in REG_EQUIV notes by defining
> LEGITIMATE_PIC_OPERAND_P to reject a CONST_DOUBLE.
This is pretty much what my ugly patch does.
--
Geoffrey Keating <geoffk@ozemail.com.au>