Re: make regclass to use estimated basic block frequencies

[Richard Henderson <rth at redhat dot com>]

On Wed, Jun 20, 2001 at 05:33:10PM +0200, Jan Hubicka wrote:
> 	* regclass.c (loop_cost): Kill.
> 	(frequency): New global variable.
> 	(record_operand_costs): Replace loop_cost by frequency.
> 	(scan_one_insn): Likewise.
> 	(regclass): Likewise; set frequency according to bb->frequency.

Ok.

On a related note, I was looking at your frequency estimation output.
Something isn't quite right.  Consider

void f2(int n)
{
  int i, j;
  for (i = 0; i < n; ++i)
    for (j = 0; j < n; ++j)
      foo();
}

The correct answer should have the inner loop blocks run more than
the outer loop blocks run more than the entry block.  Instead we see

Basic block 0: first insn 65, last 75, loop_depth 0, count 0, freq 1526.
Basic block 1: first insn 100, last 94, loop_depth 0, count 0, freq 916.
Basic block 2: first insn 19, last 81, loop_depth 1, count 0, freq 1665.
Basic block 3: first insn 101, last 87, loop_depth 1, count 0, freq 999.
Basic block 4: first insn 29, last 92, loop_depth 2, count 0, freq 10000.
Basic block 5: first insn 82, last 99, loop_depth 1, count 0, freq 1582.
Basic block 6: first insn 76, last 72, loop_depth 0, count 0, freq 686.

which shows only the inner block being reflected clearly.


r~