[PATCH] vect: Fix SVE mask_gather_load/store_store tests

Richard Sandiford richard.sandiford@arm.com
Fri Nov 12 17:55:47 GMT 2021

If-conversion now applies rewrite_to_defined_overflow to the
address calculation in an IFN_MASK_LOAD.  This means that we
end up with:

    cast_base = (uintptr_t) base;
    uncast_sum = cast_base + offset;
    sum = (orig_type *) uncast_sum;

If the target supports IFN_MASK_GATHER_LOAD with pointer-sized
offsets for the given vectype, we wouldn't look through the sum
cast and so would needlessly vectorise the uncast_sum addition.

This showed up as several failures in gcc.target/aarch64/sve.

Regstrapped on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?


	* tree-vect-data-refs.c (vect_check_gather_scatter): Continue
	processing conversions if the current offset is a pointer.
 gcc/tree-vect-data-refs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index f1d7f01a9ce..888ad72f3a9 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -4139,6 +4139,7 @@ vect_check_gather_scatter (stmt_vec_info stmt_info, loop_vec_info loop_vinfo,
 	  /* Don't include the conversion if the target is happy with
 	     the current offset type.  */
 	  if (use_ifn_p
+	      && !POINTER_TYPE_P (TREE_TYPE (off))
 	      && vect_gather_scatter_fn_p (loop_vinfo, DR_IS_READ (dr),
 					   masked_p, vectype, memory_type,
 					   TREE_TYPE (off), scale, &ifn,

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