Fix permute handling when vectorising scatters
Richard Sandiford
richard.sandiford@linaro.org
Tue Jan 9 11:39:00 GMT 2018
As mentioned in https://gcc.gnu.org/ml/gcc-patches/2017-11/msg01575.html ,
the scatter handling in vectorizable_store seems to be dead code at the
moment. Enabling it with the vect_analyze_data_ref_access part of
that patch triggered an ICE in the avx512f-scatter-*.c tests (which
previously didn't use scatters). The problem was that the NARROW
and WIDEN handling uses permute_vec_elements to marshal the inputs,
and permute_vec_elements expected the lhs of the stmt to be an SSA_NAME,
which of course it isn't for stores.
This patch makes permute_vec_elements create a fresh variable in this case.
Tested on x86_64-linux-gnu. OK to install?
Richard
2018-01-09 Richard Sandiford <richard.sandiford@linaro.org>
gcc/
* tree-vect-stmts.c (permute_vec_elements): Create a fresh variable
if the destination isn't an SSA_NAME.
Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c 2018-01-03 21:47:27.956862491 +0000
+++ gcc/tree-vect-stmts.c 2018-01-09 11:30:00.578821631 +0000
@@ -6585,7 +6585,11 @@ permute_vec_elements (tree x, tree y, tr
tree perm_dest, data_ref;
gimple *perm_stmt;
- perm_dest = vect_create_destination_var (gimple_get_lhs (stmt), vectype);
+ tree scalar_dest = gimple_get_lhs (stmt);
+ if (TREE_CODE (scalar_dest) == SSA_NAME)
+ perm_dest = vect_create_destination_var (scalar_dest, vectype);
+ else
+ perm_dest = vect_get_new_vect_var (vectype, vect_simple_var, NULL);
data_ref = make_ssa_name (perm_dest);
/* Generate the permute statement. */
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