From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joern Rennecke <amylaar@cygnus.co.uk>
To: crosby@qwes.math.cmu.edu
Cc: hubicka@atrey.karlin.mff.cuni.cz, egcs@cygnus.com
Subject: Re: Benchmark suite...
Date: Wed, 04 Nov 1998 23:31:00 -0000
Message-id: <199811050731.HAA25613@phal.cygnus.co.uk>
References: <Pine.LNX.3.95.981022211744.14603A-100000@qwe4.math.cmu.edu>
X-SW-Source: 1998-11/msg00203.html

> Another micro-benchmark to measure how well the compiler performs register
> assignment:
> 
> // Test register assignment, passing reg_assignXX an array of XX values.
> reg_assign1_8(int *a, int *b)
> 	b[0] = 1*a[1] + 2*a[2] + 3*a[3] +  4*a[4] .... 7*a[7];
> 	b[1] = 0*a[0] + 1*a[2] + 2*a[3] .... 6*a[7];
> ..
> ..
>         b[7] =  0*a[0] + ... + 1*a[7];
> }
> 
> Here, the constants in the right hand sides were chosen so that a simple
> CSE would not work well on them, so this would test how well the compiler
> performs register assignment.. (It could also test a much more advanced
> CSE that could simplify this.) Again, a list of functons reg_assign1_16(),
> reg_assign1_32(), are created...

This does not work.  a and b can be aliased.