On Wed, Jun 26, 2019 at 12:19:28PM +0200, Uros Bizjak wrote:
> Yes, the patch works OK. I'll regression test it and push it later today.
I think it caused
+FAIL: gcc.dg/tree-ssa/pr84512.c scan-tree-dump optimized "return 285;"
which admittedly already is xfailed on various targets.
We now newly vectorize those loops and there is no FRE or similar pass
after vectorization to clean it up, in particular optimize the
a[8] and a[9] loads given the MEM <vector(2) int> [(int *)&a + 32B]
store:
MEM <vector(2) int> [(int *)&a + 32B] = { 64, 81 };
_13 = a[8];
res_6 = _13 + 140;
_18 = a[9];
res_15 = res_6 + _18;
a ={v} {CLOBBER};
return res_15;
Shall we xfail it, or is there a plan to enable FRE after vectorization,
or similar pass that would be able to do similar memory optimizations?
Note, the RTL passes are able to optimize it in the end in this testcase.
Jakub
