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Re: [tree-ssa] More CCP fixes [patch]
- From: Mark Mitchell <mark at codesourcery dot com>
- To: Neil Booth <neil at daikokuya dot co dot uk>, Richard Henderson <rth at redhat dot com>, Jason Merrill <jason at redhat dot com>, Diego Novillo <dnovillo at redhat dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 12 Aug 2002 15:44:27 -0700
- Subject: Re: [tree-ssa] More CCP fixes [patch]
1) its true type (3 bit unsigned int) in the current type field
That is only its true type when used as an lvalue. When used as an
rvalue, its true type is whatever it was declared to be (int, unsigned
int, etc. -- modulo the fact that "int" can mean "unsigned int"
in a bitfield.)
A reference to a bit-field in an rvalue context should be treated as
implicitly containing the right sign extensions. That means that the
tree node used to convert from (say) "unsigned int" to "signed int"
should not be a NOP_EXPR -- you're not supposed to have generate code
for a NOP_EXPR.
--
Mark Mitchell mark@codesourcery.com
CodeSourcery, LLC http://www.codesourcery.com