On 5/26/2021 11:29 AM, Andrew MacLeod via Gcc-patches wrote:
On 5/26/21 7:07 AM, Andrew Pinski wrote:
On Wed, May 26, 2021 at 2:01 AM Andrew Pinski <pins...@gmail.com> wrote:
On Wed, May 26, 2021 at 1:43 AM Bernd Edlinger
<bernd.edlin...@hotmail.de> wrote:
On 5/25/21 4:22 PM, Richard Biener via Gcc-patches wrote:
On Sun, May 23, 2021 at 12:03 PM apinski--- via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
From: Andrew Pinski <apin...@marvell.com>
Instead of some of the more manual optimizations inside phi-opt,
it would be good idea to do a lot of the heavy lifting inside match
and simplify instead. In the process, this moves the three simple
A?CST1:CST2 (where CST1 or CST2 is zero) simplifications.
OK? Boostrapped and tested on x86_64-linux-gnu with no regressions.
Differences from V1:
* Use bit_xor 1 instead of bit_not to fix the problem with
boolean types
which are not 1 bit precision.
OK.
Thanks,
Richard.
Hmm, sorry, no luck.
I think this caused:
If anything it is a bad interaction with changes between r12-1046 and
r12-1053; I am suspecting a bug in those changes rather than my
changes causing the bug. Debugging it right now.
(gdb) p debug_tree(name)
<ssa_name 0x7ffff6a5cd38
type <boolean_type 0x7ffff6b45b28 _Bool public unsigned QI
size <integer_cst 0x7ffff6b2bdc8 constant 8>
unit-size <integer_cst 0x7ffff6b2bde0 constant 1>
align:8 warn_if_not_align:0 symtab:0 alias-set -1
canonical-type 0x7ffff6b45b28 precision:1 min <integer_cst
0x7ffff6b4a030 0> max <integer_cst 0x7ffff6b4a060 1>>
def_stmt _19 = ~_8;
version:19>
So what is happening is evrp converted:
ct_12 = ct_5 + -1;
Into
ct_12 = ct_5 == 1 ? 0 : 1;
(this was done before my patch)
And then it gets simplified to:
_8 = ct_5 == 1;
_19 = ~_8;
ct_12 = (int) _19;
(after my match.pd patch)
Yup. I've chased this kind of thing down repeatedly through the years.
It's rare, but some transformations from match.pd create new SSA_NAMEs
and the various passes need to be prepared to handle that.
Jeff
