https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63679
--- Comment #35 from alalaw01 at gcc dot gnu.org ---
So it should be happening in dom2. On x86, input to dom2 is
vect_cst_.9_31 = { 0, 1, 2, 3 };
[...]MEM[(int *)&a] = vect_cst_.9_31;
[...]vect__13.3_20 = MEM[(int *)&a];
resulting in:
Optimizing statement vect_cst_.9_31 = { 0, 1, 2, 3 };
LKUP STMT vect_cst_.9_31 = { 0, 1, 2, 3 }
==== ASGN vect_cst_.9_31 = { 0, 1, 2, 3 }
...
Optimizing statement MEM[(int *)&a] = vect_cst_.9_31;
Replaced 'vect_cst_.9_31' with constant '{ 0, 1, 2, 3 }'
LKUP STMT MEM[(int *)&a] = { 0, 1, 2, 3 } with .MEM_3(D)
LKUP STMT { 0, 1, 2, 3 } = MEM[(int *)&a] with .MEM_3(D)
LKUP STMT { 0, 1, 2, 3 } = MEM[(int *)&a] with .MEM_17
2>>> STMT { 0, 1, 2, 3 } = MEM[(int *)&a] with .MEM_17
...
Optimizing statement vect__13.3_20 = MEM[(int *)&a];
LKUP STMT vect__13.3_20 = MEM[(int *)&a] with .MEM_21
FIND: { 0, 1, 2, 3 }
Replaced redundant expr 'MEM[(int *)&a]' with '{ 0, 1, 2, 3 }'
My version has input to dom2:
vect_cst_.8_27 = { 0, 1, 2, 3 };
[...]MEM[(int[8] *)&a] = vect_cst_.8_27;
[...]vect__8.3_20 = MEM[(int *)&a];
Optimizing statement vect_cst_.8_27 = { 0, 1, 2, 3 };
LKUP STMT vect_cst_.8_27 = { 0, 1, 2, 3 }
==== ASGN vect_cst_.8_27 = { 0, 1, 2, 3 }
...
Optimizing statement MEM[(int[8] *)&a] = vect_cst_.8_27;
Replaced 'vect_cst_.8_27' with constant '{ 0, 1, 2, 3 }'
LKUP STMT MEM[(int[8] *)&a] = { 0, 1, 2, 3 } with .MEM_3(D)
LKUP STMT { 0, 1, 2, 3 } = MEM[(int[8] *)&a] with .MEM_3(D)
LKUP STMT { 0, 1, 2, 3 } = MEM[(int[8] *)&a] with .MEM_17
2>>> STMT { 0, 1, 2, 3 } = MEM[(int[8] *)&a] with .MEM_17
...
Optimizing statement vect__8.3_20 = MEM[(int *)&a];
LKUP STMT vect__8.3_20 = MEM[(int *)&a] with .MEM_21
2>>> STMT vect__8.3_20 = MEM[(int *)&a] with .MEM_21
Which looks like MEM[(int *)&a] and MEM[(int[8] *)&a] are hashing differently
and hence dom2 is not finding it.
Could be that I need my SRA to output something closer to
a[1] = 1;
where I currently have
MEM[(int[8] *)&a + 4B] = 1;
but also feel that those two statements hashing differently is not really
helpful!
