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Re: Proposed patch for loop.c
- To: crux at Pool dot Informatik dot RWTH-Aachen dot DE (Bernd Schmidt)
- Subject: Re: Proposed patch for loop.c
- From: Joern Rennecke <amylaar at cygnus dot co dot uk>
- Date: Fri, 1 Sep 2000 17:13:06 +0100
- Cc: gcc-patches at gcc dot gnu dot org
In article <Pine.SOL.3.90.980528110457.28555H-100000.cygnus.egcs.patches@matlock.informatik.rwth-aachen.de> you wrote:
...
: I found two problems. First, general_induction_var returns the benefit of
: a giv, but it always returns 1 even if it calculated a benefit of zero.
: In combine_givs, the benefits of multiple givs can be added up in some cases,
: possibly increasing the error quite a bit. Thus I think it's better to
: have general_induction_var return zero or nonzero depending on whether X
: is a giv or not, and accept a pointer to an int in which it can store the
: benefit.
Why not return a negative number for 'no giv'?