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Re: strange double comparison results with -O[12] on x86(-32)
- From: Robert Dewar <dewar at adacore dot com>
- To: Dave Korn <dave dot korn at artimi dot com>
- Cc: 'Florian Weimer' <fw at deneb dot enyo dot de>,'Andrew Pinski' <pinskia at physics dot uc dot edu>,'Christian Bodenstedt' <c dot bodenstedt at cityweb dot de>, gcc at gcc dot gnu dot org
- Date: Mon, 13 Jun 2005 19:41:23 -0400
- Subject: Re: strange double comparison results with -O[12] on x86(-32)
- References: <SERRANOVdhUXtuhgYZB00000016@SERRANO.CAM.ARTIMI.COM>
Dave Korn wrote:
... or it's a bug in the libc/crt-startup, which is where the hardware
rounding mode is (or should be) set up ...
Well if you think that the operations should reflect IEEE 64-bit semantics
(which is the only rationale for mucking with the rounding mode in the
startup), then this is only an approximate fix, since the intermediate
values still have excessive range, so you don't get infinities when
expected.