Hi, In vectorization of reduction we use a dummy def_type when getting a copy of a vector operand. Therefore, instead of just using a constant operand from a previous copy, we try to create a copy of it, causing the failure. This patch adds a call to vect_is_simple_use () to get a correct def_type.
Bootstrapped and tested on powerpc64-suse-linux. Committed. Ira ChangeLog: PR tree-optimization/50014 * tree-vect-loop.c (vectorizable_reduction): Get def type before calling vect_get_vec_def_for_stmt_copy (). testsuite/ChangeLog: PR tree-optimization/50014 * gcc.dg/vect/pr50014.c: New test. Index: tree-vect-loop.c =================================================================== --- tree-vect-loop.c (revision 177580) +++ tree-vect-loop.c (working copy) @@ -4318,7 +4318,7 @@ vectorizable_reduction (gimple stmt, gimple_stmt_i VEC (tree, heap) *vec_oprnds0 = NULL, *vec_oprnds1 = NULL, *vect_defs = NULL; VEC (gimple, heap) *phis = NULL; int vec_num; - tree def0, def1, tem; + tree def0, def1, tem, op0, op1 = NULL_TREE; /* In case of reduction chain we switch to the first stmt in the chain, but we don't update STMT_INFO, since only the last stmt is marked as reduction @@ -4775,8 +4775,6 @@ vectorizable_reduction (gimple stmt, gimple_stmt_i /* Handle uses. */ if (j == 0) { - tree op0, op1 = NULL_TREE; - op0 = ops[!reduc_index]; if (op_type == ternary_op) { @@ -4806,11 +4804,19 @@ vectorizable_reduction (gimple stmt, gimple_stmt_i { if (!slp_node) { - enum vect_def_type dt = vect_unknown_def_type; /* Dummy */ - loop_vec_def0 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def0); + enum vect_def_type dt; + gimple dummy_stmt; + tree dummy; + + vect_is_simple_use (ops[!reduc_index], loop_vinfo, NULL, + &dummy_stmt, &dummy, &dt); + loop_vec_def0 = vect_get_vec_def_for_stmt_copy (dt, + loop_vec_def0); VEC_replace (tree, vec_oprnds0, 0, loop_vec_def0); if (op_type == ternary_op) { + vect_is_simple_use (op1, loop_vinfo, NULL, &dummy_stmt, + &dummy, &dt); loop_vec_def1 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def1); VEC_replace (tree, vec_oprnds1, 0, loop_vec_def1); Index: testsuite/gcc.dg/vect/pr50014.c =================================================================== --- testsuite/gcc.dg/vect/pr50014.c (revision 0) +++ testsuite/gcc.dg/vect/pr50014.c (revision 0) @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-require-effective-target vect_int } */ + +int f(unsigned char *s, int n) +{ + int sum = 0; + int i; + + for (i = 0; i < n; i++) + sum += 256 * s[i]; + + return sum; +} + +/* { dg-final { cleanup-tree-dump "vect" } } */ +