[PATCH] Allow vectorization of __builtin_bswap16 (PR tree-optimization/91940)
Jakub Jelinek
jakub@redhat.com
Wed Oct 2 09:47:00 GMT 2019
On Wed, Nov 09, 2016 at 09:14:55AM +0100, Richard Biener wrote:
> The following implements vectorization of bswap via VEC_PERM_EXPR
> on the corresponding QImode vector.
>
> ARM already has backend handling via the builtin_vectorized_call
> hook and thus there were already testcases available. It doesn't
> end up working for vect-bswap16.c because we have a promoted
> argument to __builtin_bswap16 which confuses vectorization.
Indeed. The following patch handles that in tree-vect-patterns.c.
If it sees a __builtin_bswap16 with the promoted argument, it checks if we'd
vectorize the builtin if it didn't have a promoted argument and if yes,
it just changes it in a pattern_stmt to use an unpromoted argument or casts
it first to the right type. This works e.g. for the SSE4 case.
Otherwise, it handles __builtin_bswap16 like a x r<< 8, if that is
vectorizable, emits a pattern_stmt with x r<< 8, if it isn't, falls back to
(x << 8) | (x >> 8) if that can be vectorized. The last case matters for SSE2.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-10-02 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/91940
* tree-vect-patterns.c: Include tree-vector-builder.h and
vec-perm-indices.h.
(vect_recog_rotate_pattern): Also handle __builtin_bswap16, either by
unpromoting the argument back to uint16_t, or by converting into a
rotate, or into shifts plus ior.
* gcc.dg/vect/vect-bswap16.c: Add -msse4 on x86, run on all targets,
expect vectorized 1 loops message on both vect_bswap and sse4_runtime
targets.
* gcc.dg/vect/vect-bswap16a.c: New test.
--- gcc/tree-vect-patterns.c.jj 2019-09-20 12:25:48.186387075 +0200
+++ gcc/tree-vect-patterns.c 2019-10-01 11:29:18.229215895 +0200
@@ -46,6 +46,8 @@ along with GCC; see the file COPYING3.
#include "cgraph.h"
#include "omp-simd-clone.h"
#include "predict.h"
+#include "tree-vector-builder.h"
+#include "vec-perm-indices.h"
/* Return true if we have a useful VR_RANGE range for VAR, storing it
in *MIN_VALUE and *MAX_VALUE if so. Note the range in the dump files. */
@@ -2168,24 +2170,107 @@ vect_recog_rotate_pattern (stmt_vec_info
enum vect_def_type dt;
optab optab1, optab2;
edge ext_def = NULL;
+ bool bswap16_p = false;
- if (!is_gimple_assign (last_stmt))
- return NULL;
-
- rhs_code = gimple_assign_rhs_code (last_stmt);
- switch (rhs_code)
+ if (is_gimple_assign (last_stmt))
{
- case LROTATE_EXPR:
- case RROTATE_EXPR:
- break;
- default:
- return NULL;
+ rhs_code = gimple_assign_rhs_code (last_stmt);
+ switch (rhs_code)
+ {
+ case LROTATE_EXPR:
+ case RROTATE_EXPR:
+ break;
+ default:
+ return NULL;
+ }
+
+ lhs = gimple_assign_lhs (last_stmt);
+ oprnd0 = gimple_assign_rhs1 (last_stmt);
+ type = TREE_TYPE (oprnd0);
+ oprnd1 = gimple_assign_rhs2 (last_stmt);
+ }
+ else if (gimple_call_builtin_p (last_stmt, BUILT_IN_BSWAP16))
+ {
+ /* __builtin_bswap16 (x) is another form of x r>> 8.
+ The vectorizer has bswap support, but only if the argument isn't
+ promoted. */
+ lhs = gimple_call_lhs (last_stmt);
+ oprnd0 = gimple_call_arg (last_stmt, 0);
+ type = TREE_TYPE (oprnd0);
+ if (TYPE_PRECISION (TREE_TYPE (lhs)) != 16
+ || TYPE_PRECISION (type) <= 16
+ || TREE_CODE (oprnd0) != SSA_NAME
+ || BITS_PER_UNIT != 8
+ || !TYPE_UNSIGNED (TREE_TYPE (lhs)))
+ return NULL;
+
+ stmt_vec_info def_stmt_info;
+ if (!vect_is_simple_use (oprnd0, vinfo, &dt, &def_stmt_info, &def_stmt))
+ return NULL;
+
+ if (dt != vect_internal_def)
+ return NULL;
+
+ if (gimple_assign_cast_p (def_stmt))
+ {
+ def = gimple_assign_rhs1 (def_stmt);
+ if (INTEGRAL_TYPE_P (TREE_TYPE (def))
+ && TYPE_PRECISION (TREE_TYPE (def)) == 16)
+ oprnd0 = def;
+ }
+
+ type = TREE_TYPE (lhs);
+ vectype = get_vectype_for_scalar_type (type);
+ if (vectype == NULL_TREE)
+ return NULL;
+
+ if (tree char_vectype = get_same_sized_vectype (char_type_node, vectype))
+ {
+ /* The encoding uses one stepped pattern for each byte in the
+ 16-bit word. */
+ vec_perm_builder elts (TYPE_VECTOR_SUBPARTS (char_vectype), 2, 3);
+ for (unsigned i = 0; i < 3; ++i)
+ for (unsigned j = 0; j < 2; ++j)
+ elts.quick_push ((i + 1) * 2 - j - 1);
+
+ vec_perm_indices indices (elts, 1,
+ TYPE_VECTOR_SUBPARTS (char_vectype));
+ if (can_vec_perm_const_p (TYPE_MODE (char_vectype), indices))
+ {
+ /* vectorizable_bswap can handle the __builtin_bswap16 if we
+ undo the argument promotion. */
+ if (!useless_type_conversion_p (type, TREE_TYPE (oprnd0)))
+ {
+ def = vect_recog_temp_ssa_var (type, NULL);
+ def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd0);
+ append_pattern_def_seq (stmt_vinfo, def_stmt);
+ oprnd0 = def;
+ }
+
+ /* Pattern detected. */
+ vect_pattern_detected ("vect_recog_rotate_pattern", last_stmt);
+
+ *type_out = vectype;
+
+ /* Pattern supported. Create a stmt to be used to replace the
+ pattern, with the unpromoted argument. */
+ var = vect_recog_temp_ssa_var (type, NULL);
+ pattern_stmt = gimple_build_call (gimple_call_fndecl (last_stmt),
+ 1, oprnd0);
+ gimple_call_set_lhs (pattern_stmt, var);
+ gimple_call_set_fntype (as_a <gcall *> (pattern_stmt),
+ gimple_call_fntype (last_stmt));
+ return pattern_stmt;
+ }
+ }
+
+ oprnd1 = build_int_cst (integer_type_node, 8);
+ rhs_code = LROTATE_EXPR;
+ bswap16_p = true;
}
+ else
+ return NULL;
- lhs = gimple_assign_lhs (last_stmt);
- oprnd0 = gimple_assign_rhs1 (last_stmt);
- type = TREE_TYPE (oprnd0);
- oprnd1 = gimple_assign_rhs2 (last_stmt);
if (TREE_CODE (oprnd0) != SSA_NAME
|| TYPE_PRECISION (TREE_TYPE (lhs)) != TYPE_PRECISION (type)
|| !INTEGRAL_TYPE_P (type)
@@ -2210,14 +2295,39 @@ vect_recog_rotate_pattern (stmt_vec_info
optab1 = optab_for_tree_code (rhs_code, vectype, optab_vector);
if (optab1
&& optab_handler (optab1, TYPE_MODE (vectype)) != CODE_FOR_nothing)
- return NULL;
+ {
+ use_rotate:
+ if (bswap16_p)
+ {
+ if (!useless_type_conversion_p (type, TREE_TYPE (oprnd0)))
+ {
+ def = vect_recog_temp_ssa_var (type, NULL);
+ def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd0);
+ append_pattern_def_seq (stmt_vinfo, def_stmt);
+ oprnd0 = def;
+ }
+
+ /* Pattern detected. */
+ vect_pattern_detected ("vect_recog_rotate_pattern", last_stmt);
+
+ *type_out = vectype;
+
+ /* Pattern supported. Create a stmt to be used to replace the
+ pattern. */
+ var = vect_recog_temp_ssa_var (type, NULL);
+ pattern_stmt = gimple_build_assign (var, LROTATE_EXPR, oprnd0,
+ oprnd1);
+ return pattern_stmt;
+ }
+ return NULL;
+ }
if (is_a <bb_vec_info> (vinfo) || dt != vect_internal_def)
{
optab2 = optab_for_tree_code (rhs_code, vectype, optab_scalar);
if (optab2
&& optab_handler (optab2, TYPE_MODE (vectype)) != CODE_FOR_nothing)
- return NULL;
+ goto use_rotate;
}
/* If vector/vector or vector/scalar shifts aren't supported by the target,
@@ -2242,6 +2352,14 @@ vect_recog_rotate_pattern (stmt_vec_info
*type_out = vectype;
+ if (bswap16_p && !useless_type_conversion_p (type, TREE_TYPE (oprnd0)))
+ {
+ def = vect_recog_temp_ssa_var (type, NULL);
+ def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd0);
+ append_pattern_def_seq (stmt_vinfo, def_stmt);
+ oprnd0 = def;
+ }
+
if (dt == vect_external_def
&& TREE_CODE (oprnd1) == SSA_NAME)
ext_def = vect_get_external_def_edge (vinfo, oprnd1);
--- gcc/testsuite/gcc.dg/vect/vect-bswap16.c.jj 2017-11-09 20:24:05.957112733 +0100
+++ gcc/testsuite/gcc.dg/vect/vect-bswap16.c 2019-10-01 12:39:56.993268063 +0200
@@ -1,4 +1,4 @@
-/* { dg-require-effective-target vect_bswap } */
+/* { dg-additional-options "-msse4" { target sse4_runtime } } */
#include "tree-vect.h"
@@ -39,4 +39,4 @@ main (void)
return 0;
}
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target { vect_bswap || sse4_runtime } } } } */
--- gcc/testsuite/gcc.dg/vect/vect-bswap16a.c.jj 2019-10-01 12:35:29.965294527 +0200
+++ gcc/testsuite/gcc.dg/vect/vect-bswap16a.c 2019-10-01 12:40:45.700533603 +0200
@@ -0,0 +1,5 @@
+/* { dg-additional-options "-msse2 -mno-sse3" { target sse2_runtime } } */
+
+#include "vect-bswap16.c"
+
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target { vect_shift } } } } */
Jakub
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