As suggested by Richard B., this patch makes vect_is_simple_use check
whether a defining statement has been replaced by a pattern statement,
and if so returns the pattern statement instead.
The reason for doing this is that the main patch for PR85694
makes over_widening handle more general cases. These over-widened
patterns can still be useful when matching later statements;
e.g. an overwidened MULT_EXPR could be the input to a DOT_PROD_EXPR.
The patch doesn't do anything with the STMT_VINFO_IN_PATTERN_P checks
in vect_recog_over_widening_pattern or vect_recog_widen_shift_pattern
since later patches rewrite them anyway.
Doing this fixed an XFAIL in vect-reduc-dot-u16b.c.
2018-06-30 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* tree-vect-loop.c (vectorizable_reduction): Assert that the
phi is not a pattern statement and has not been replaced by
a pattern statement.
* tree-vect-patterns.c (type_conversion_p): Don't check
STMT_VINFO_IN_PATTERN_P.
(vect_recog_vector_vector_shift_pattern): Likewise.
(vect_recog_dot_prod_pattern): Expect vect_is_simple_use to return
the pattern statement rather than the original statement; check
directly for a WIDEN_MULT_EXPR here.
* tree-vect-slp.c (vect_get_and_check_slp_defs): Expect
vect_is_simple_use to return the pattern statement rather
than the original statement; use is_pattern_stmt_p to check
for such a pattern statement.
* tree-vect-stmts.c (process_use): Expect vect_is_simple_use
to return the pattern statement rather than the original statement;
don't do the same transformation here.
(vect_is_simple_use): If the defining statement has been replaced
by a pattern statement, return the pattern statement instead.
Remove the corresponding (local) transformation from the vectype
overload.
gcc/testsuite/
* gcc.dg/vect/vect-reduc-dot-u16b.c: Remove xfail and update the
test for vectorization along the lines described in the comment.
From-SVN: r262273
