On Wed, Jan 15, 2014 at 02:06:24PM +0100, Richard Biener wrote:
>
> This should fix PR59822, us creating in valid SSA form when
> hoisting a[i_2] out of a loop where i_2 is defined inside the loop.
>
> Bootstrap / regtest running on x86_64-unknown-linux-gnu.
Unfortunately with my patch on top of that (with obvious adjustment
that it applies against the changed vectorizable_load code)
still fails on lots of testcases, e.g.
/usr/src/gcc/obj877/gcc/xgcc -B/usr/src/gcc/obj877/gcc/
/usr/src/gcc/gcc/testsuite/gcc.dg/vect/pr31343.c -fno-diagnostics-show-caret
-fdiagnostics-color=never -msse2 -ftree-vectorize -fno-vect-cost-model
-fno-common -O2 -fdump-tree-vect-details -S -o pr31343.s
/usr/src/gcc/gcc/testsuite/gcc.dg/vect/pr31343.c: In function 'main1':
/usr/src/gcc/gcc/testsuite/gcc.dg/vect/pr31343.c:12:1: internal compiler error:
in op_iter_init, at ssa-iterators.h:602
0x89aa2fe op_iter_init
../../gcc/ssa-iterators.h:600
0x81232a9 op_iter_init
../../gcc/ssa-iterators.h:600
0x89bd936 op_iter_init_tree
../../gcc/ssa-iterators.h:662
0x89bd936 hoist_defs_of_uses
../../gcc/tree-vect-stmts.c:5507
0x89bd936 vectorizable_load
../../gcc/tree-vect-stmts.c:6442
I think that has to do with nested loop vectorization and
inv_p being true in the inner loop for:
# j_54 = PHI <j_45(5), 0(4)>
...
_40 = ub[j_54];
and thus def_stmt is GIMPLE_PHI and
FOR_EACH_SSA_TREE_OPERAND isn't allowed on those.
Perhaps we want to avoid doing the hoisting for nested loop vectorization?
And perhaps hoist_defs_of_uses should return false if
gimple_code (def_stmt) == GIMPLE_PHI?
Jakub
