Re: [tree-ssa] bootstrap problem on powerpc-apple-darwin6.6

[law at redhat dot com]

In message <200308220001.h7M013m28429@tin.geop.uc.edu>, Andrew Pinski writes:
 >> 
 >> On Thu, 21 Aug 2003 16:53:04 -0400, Daniel Berlin <dberlin@dberlin.org> wro
 >te:
 >> 
 >> > This stripping you do undoes what gimple_boolify_expr did to convert it t
 >o
 >> > a boolean_type.
 >> > Then invert_truthop aborts when it tries to invert a non-boolean_type tre
 >e.
 >> > So either
 >> > 1. The conversion isn't useless, but gimplify_boolify_expr is not
 >> > generating the conversion in a way that makes it seem un-useless.
 >> > 2. The conversion isn't useless, and the above is not working like it
 >> > should.
 >> 
 >> I think the conversion isn't useless, because BOOLEAN_TYPE has a (much)
 >> smaller range of values, which matters to invert_truthop, at least, and
 >> should be useful to optimizers.
 >> 
 >
 >Would this patch be acceptable?
 >It gets my by the part where I was failing.
 >
 >Thanks,
 >Andrew Pinski
 >
 >ChangeLog.tree-ssa:
 >	* tree-ssa.c (tree_ssa_useless_type_conversion): Types are only equal
 >	if they have the same min and max values.
So, two types can have the same mode, but different min/max values?  I guess
that makes a certain amount of sense.

Ugh.  I learn more about trees every day...  Some things are good, some things
are bad.

This is probably going to cause some missed optimizations.  I guess we'll
find another way to deal with them.

Jeff