Re: [PATCH] Strength reduction part 3 of 4: candidates with unknown strides

[Janis Johnson <janis_johnson at mentor dot com>]

On 08/08/2012 03:27 PM, Andrew Pinski wrote:
> On Wed, Aug 8, 2012 at 3:25 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Wed, Aug 1, 2012 at 10:36 AM, William J. Schmidt
>> <wschmidt@linux.vnet.ibm.com> wrote:
>>> Greetings,
>>>
>>> Thanks for the review of part 2!  Here's another chunk of the SLSR code
>>> (I feel I owe you a few beers at this point).  This performs analysis
>>> and replacement on groups of related candidates having an SSA name
>>> (rather than a constant) for a stride.
>>>
>>> This leaves only the conditional increment (CAND_PHI) case, which will
>>> be handled in the last patch of the series.
>>>
>>> Bootstrapped and tested on powerpc64-unknown-linux-gnu with no new
>>> regressions.  Ok for trunk?
>>>
>>> Thanks,
>>> Bill
>>>
>>>
>>> gcc:
>>>
>>> 2012-08-01  Bill Schmidt  <wschmidt@linux.ibm.com>
>>>
>>>         * gimple-ssa-strength-reduction.c (struct incr_info_d): New struct.
>>>         (incr_vec): New static var.
>>>         (incr_vec_len): Likewise.
>>>         (address_arithmetic_p): Likewise.
>>>         (stmt_cost): Remove dead assignment.
>>>         (dump_incr_vec): New function.
>>>         (cand_abs_increment): Likewise.
>>>         (lazy_create_slsr_reg): Likewise.
>>>         (incr_vec_index): Likewise.
>>>         (count_candidates): Likewise.
>>>         (record_increment): Likewise.
>>>         (record_increments): Likewise.
>>>         (unreplaced_cand_in_tree): Likewise.
>>>         (optimize_cands_for_speed_p): Likewise.
>>>         (lowest_cost_path): Likewise.
>>>         (total_savings): Likewise.
>>>         (analyze_increments): Likewise.
>>>         (ncd_for_two_cands): Likewise.
>>>         (nearest_common_dominator_for_cands): Likewise.
>>>         (profitable_increment_p): Likewise.
>>>         (insert_initializers): Likewise.
>>>         (introduce_cast_before_cand): Likewise.
>>>         (replace_rhs_if_not_dup): Likewise.
>>>         (replace_one_candidate): Likewise.
>>>         (replace_profitable_candidates): Likewise.
>>>         (analyze_candidates_and_replace): Handle candidates with SSA-name
>>>         strides.
>>>
>>> gcc/testsuite:
>>>
>>> 2012-08-01  Bill Schmidt  <wschmidt@linux.ibm.com>
>>>
>>>         * gcc.dg/tree-ssa/slsr-5.c: New.
>>>         * gcc.dg/tree-ssa/slsr-6.c: New.
>>>         * gcc.dg/tree-ssa/slsr-7.c: New.
>>>         * gcc.dg/tree-ssa/slsr-8.c: New.
>>>         * gcc.dg/tree-ssa/slsr-9.c: New.
>>>         * gcc.dg/tree-ssa/slsr-10.c: New.
>>>         * gcc.dg/tree-ssa/slsr-11.c: New.
>>>         * gcc.dg/tree-ssa/slsr-12.c: New.
>>>         * gcc.dg/tree-ssa/slsr-13.c: New.
>>>         * gcc.dg/tree-ssa/slsr-14.c: New.
>>>         * gcc.dg/tree-ssa/slsr-15.c: New.
>>>         * gcc.dg/tree-ssa/slsr-16.c: New.
>>>         * gcc.dg/tree-ssa/slsr-17.c: New.
>>>         * gcc.dg/tree-ssa/slsr-18.c: New.
>>>         * gcc.dg/tree-ssa/slsr-19.c: New.
>>>         * gcc.dg/tree-ssa/slsr-20.c: New.
>>>         * gcc.dg/tree-ssa/slsr-21.c: New.
>>>         * gcc.dg/tree-ssa/slsr-22.c: New.
>>>         * gcc.dg/tree-ssa/slsr-23.c: New.
>>>         * gcc.dg/tree-ssa/slsr-24.c: New.
>>>         * gcc.dg/tree-ssa/slsr-25.c: New.
>>>         * gcc.dg/tree-ssa/slsr-26.c: New.
>>>         * gcc.dg/tree-ssa/slsr-30.c: New.
>>>         * gcc.dg/tree-ssa/slsr-31.c: New.
>>>
>>>
>> ======================================
>>> --- gcc/testsuite/gcc.dg/tree-ssa/slsr-30.c     (revision 0)
>>> +++ gcc/testsuite/gcc.dg/tree-ssa/slsr-30.c     (revision 0)
>>> @@ -0,0 +1,25 @@
>>> +/* Verify straight-line strength reduction fails for simple integer addition
>>> +   with casts thrown in when -fwrapv is used.  */
>>> +
>>> +/* { dg-do compile } */
>>> +/* { dg-options "-O3 -fdump-tree-dom2 -fwrapv" } */
>>> +/* { dg-skip-if "" { ilp32 } { "-m32" } { "" } } */
>>> +
>>
>> This doesn't work on x32 nor Linux/ia32 since -m32
>> may not be needed for ILP32.  This patch works for
>> me.  OK to install?
> 
> This also does not work for mips64 where the options are either
> -mabi=32 or -mabi=n32 for ILP32.
> 
> HJL's patch looks correct.
> 
> Thanks,
> Andrew

There are GCC targets with 16-bit integers.  What's the actual
set of targets on which this test is meant to run?  There's a list
of effective-target names based on data type sizes in
<http://gcc.gnu.org/onlinedocs/gccint/Effective_002dTarget-Keywords.html#Effective_002dTarget-Keywords>.

Janis

>>
>> Thanks.
>>
>>
>> --
>> H.J.
>> ---
>>        * gcc.dg/tree-ssa/slsr-30.c: Require non-ilp32.  Remove
>>        dg-skip-if.
>>
>> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/slsr-30.c b/gcc/testsuite/gcc.dg/tree
>> -ssa/slsr-30.c
>> index fbd6897..7921f43 100644
>> --- a/gcc/testsuite/gcc.dg/tree-ssa/slsr-30.c
>> +++ b/gcc/testsuite/gcc.dg/tree-ssa/slsr-30.c
>> @@ -1,9 +1,8 @@
>>  /* Verify straight-line strength reduction fails for simple integer addition
>>     with casts thrown in when -fwrapv is used.  */
>>
>> -/* { dg-do compile } */
>> +/* { dg-do compile { target { ! { ilp32 } } } } */
>>  /* { dg-options "-O3 -fdump-tree-dom2 -fwrapv" } */
>> -/* { dg-skip-if "" { ilp32 } { "-m32" } { "" } } */
>>
>>  long
>>  f (int s, long c)
>