optimization/10362: Optimization with constant shifts and com pares fails on MIPS

[Falk Hueffner]

The following reply was made to PR optimization/10362; it has been noted by GNATS.

From: Falk Hueffner <falk.hueffner@student.uni-tuebingen.de>
To: Berger David-MGI2063 <dberger@motorola.com>
Cc: "'bangerth@dealii.org'" <bangerth@dealii.org>,
   "'gcc-bugs@gcc.gnu.org'" <gcc-bugs@gcc.gnu.org>,
   "'gcc-prs@gcc.gnu.org'" <gcc-prs@gcc.gnu.org>,
   "'nobody@gcc.gnu.org'" <nobody@gcc.gnu.org>,
   "'gcc-gnats@gcc.gnu.org'" <gcc-gnats@gcc.gnu.org>
Subject: Re: optimization/10362: Optimization with constant shifts and com pares fails on MIPS
Date: 10 Apr 2003 01:07:44 +0200

 Berger David-MGI2063 <dberger@motorola.com> writes:
 
 > volatile unsigned long i;
 > 
 > void test(void)
 > {
 >   i = (((i & 0xf0) >> 4) >= 14); /* This one generates incorrect code with -O2 */
 >   i = ((i & 0xf0) >= (14 << 4)); /* This is what the optimizer is trying to do */
 > }
 
 The optimization seems valid to me. Can you give an example where it
 fails?
 
 -- 
 	Falk