On Tue, Aug 30, 2011 at 4:31 AM, Artem Shinkarov
<artyom.shinkar...@gmail.com> wrote:
> Hi
>
> This is a patch for the explicit vector shuffling we have discussed a
> long time ago here:
> http://gcc.gnu.org/ml/gcc-patches/2010-08/msg01092.html
>
> The new patch introduces the new tree code, as we agreed, and expands
> this code by checking the vshuffle pattern in the backend.
>
> The patch at the moment lacks of some examples, but mainly it works
> fine for me. It would be nice if i386 gurus could look into the way I
> am doing the expansion.
>
> Middle-end parts seems to be more or less fine, they have not changed
> much from the previous time.
+@code{__builtin_shuffle (vec, mask)} and
+@code{__builtin_shuffle (vec0, vec1, mask)}. Both functions construct
the latter would be __builtin_shuffle2.
+bool
+expand_vec_shuffle_expr_p (enum machine_mode mode, tree v0,
+ tree v1, tree mask)
+{
+#define inner_type_size(vec) \
+ GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (vec))))
missing comment. No #defines like this please, just initialize
two temporary variables.
+
+rtx
+expand_vec_shuffle_expr (tree type, tree v0, tree v1, tree mask, rtx target)
+{
comment.
+vshuffle:
+ gcc_assert (v1 == v0);
+
+ icode = direct_optab_handler (vshuffle_optab, mode);
hmm, so we don't have a vshuffle2 optab but always go via the
builtin function, but only for constant masks there? I wonder
if we should arrange for targets to only support a vshuffle
optab (thus, transition away from the builtin) and so
unconditionally have a vshuffle2 optab only (with possibly
equivalent v1 and v0?)
I suppose Richard might remember what he had in mind back
when we discussed this.
Index: gcc/c-typeck.c
===================================================================
--- gcc/c-typeck.c (revision 177758)
+++ gcc/c-typeck.c (working copy)
@@ -2815,6 +2815,68 @@ build_function_call_vec (location_t loc,
&& !check_builtin_function_arguments (fundecl, nargs, argarray))
return error_mark_node;
+ /* Typecheck a builtin function which is declared with variable
+ argument list. */
+ if (fundecl && DECL_BUILT_IN (fundecl)
+ && DECL_BUILT_IN_CLASS (fundecl) == BUILT_IN_NORMAL)
just add to check_builtin_function_arguments which is called right
in front of your added code.
+ /* Here we change the return type of the builtin function
+ from int f(...) --> t f(...) where t is a type of the
+ first argument. */
+ fundecl = copy_node (fundecl);
+ TREE_TYPE (fundecl) = build_function_type (TREE_TYPE (firstarg),
+ TYPE_ARG_TYPES (TREE_TYPE (fundecl)));
+ function = build_fold_addr_expr (fundecl);
oh, hum - now I remember ;) Eventually the C frontend should handle
this not via the function call mechanism but similar to how Joseph
added __builtin_complex support with
2011-08-19 Joseph Myers <jos...@codesourcery.com>
* c-parser.c (c_parser_postfix_expression): Handle RID_BUILTIN_COMPLEX.
* doc/extend.texi (__builtin_complex): Document.
and then emit VEC_SHUFFLE_EXPRs directly from the frontend. Joseph?
FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
- if (!CONSTANT_CLASS_P (value))
+ if (!CONSTANT_CLASS_P (value))
watch out for spurious whitespace changes.
Index: gcc/gimplify.c
===================================================================
--- gcc/gimplify.c (revision 177758)
+++ gcc/gimplify.c (working copy)
@@ -7050,6 +7050,7 @@ gimplify_expr (tree *expr_p, gimple_seq
break;
case BIT_FIELD_REF:
+ case VEC_SHUFFLE_EXPR:
I don't think that's quite the right place given the is_gimple_lvalue
predicate on the first operand. More like
case VEC_SHUFFLE_EXPR:
goto expr_3;
+/* Vector shuffle expression. A = VEC_SHUFFLE_EXPR<v0, v1, maks>
typo, mask
+ means
+
+ freach i in length (mask):
+ A = mask[i] < length (v0) ? v0[mask[i]] : v1[mask[i]]
+*/
+DEFTREECODE (VEC_SHUFFLE_EXPR, "vec_shuffle_expr", tcc_expression, 3)
what is the (is there any?) constraint on the operand types, especially
the mask type?
Index: gcc/gimple.c
===================================================================
--- gcc/gimple.c (revision 177758)
+++ gcc/gimple.c (working copy)
@@ -2623,6 +2623,7 @@ get_gimple_rhs_num_ops (enum tree_code c
|| (SYM) == ADDR_EXPR \
|| (SYM) == WITH_SIZE_EXPR \
|| (SYM) == SSA_NAME \
+ || (SYM) == VEC_SHUFFLE_EXPR \
|| (SYM) == VEC_COND_EXPR) ? GIMPLE_SINGLE_RHS \
: GIMPLE_INVALID_RHS),
#define END_OF_BASE_TREE_CODES (unsigned char) GIMPLE_INVALID_RHS,
please make it GIMPLE_TERNARY_RHS instead.
which requires adjustment at least here:
Index: gcc/tree-ssa-operands.c
===================================================================
--- gcc/tree-ssa-operands.c (revision 177758)
+++ gcc/tree-ssa-operands.c (working copy)
@@ -943,6 +943,7 @@ get_expr_operands (gimple stmt, tree *ex
case COND_EXPR:
case VEC_COND_EXPR:
+ case VEC_SHUFFLE_EXPR:
I think it would be nicer if the builtin would be handled by the frontend
not as builtin but like __builtin_complex and we'd just deal with
VEC_SHUFFLE_EXPR throughout the middle-end, eventually
lowering it in tree-vect-generic.c. So I didn't look at the lowering
code in detail because that would obviously change then.
Defering to Joseph for a decision here and to x86 maintainers for
the target specific bits.
Thanks,
Richard.
> ChangeLog:
> 2011-08-30 Artjoms Sinkarovs <artyom.shinkar...@gmailc.com>
>
> gcc/
> * optabs.c (expand_vec_shuffle_expr_p): New function. Checks
> if given expression can be expanded by the target.
> (expand_vec_shuffle_expr): New function. Expand VEC_SHUFFLE_EXPR
> using target vector instructions.
> * optabs.h: New optab vshuffle.
> (expand_vec_shuffle_expr_p): New prototype.
> (expand_vec_shuffle_expr): New prototype.
> * genopinit.c: Adjust to support vecshuffle.
> * builtins.def: New builtin __builtin_shuffle.
> * c-typeck.c (build_function_call_vec): Typecheck
> __builtin_shuffle, allowing only two or three arguments.
> Change the type of builtin depending on the arguments.
> (digest_init): Warn when constructor has less elements than
> vector type.
> * gimplify.c (gimplify_exp): Adjusted to support VEC_SHUFFLE_EXPR.
> * tree.def: New tree code VEC_SHUFFLE_EXPR.
> * tree-vect-generic.c (vector_element): New function. Returns an
> element of the vector at the given position.
> (lower_builtin_shuffle): Change builtin_shuffle with VEC_SHUFLLE_EXPR
> or expand an expression piecewise.
> (expand_vector_operations_1): Adjusted.
> (gate_expand_vector_operations_noop): New gate function.
> * gimple.c (get_gimple_rhs_num_ops): Adjust.
> * passes.c: Move veclower down.
> * tree-pretty-print.c (dump_generic_node): Recognize
> VEC_SHUFFLE_EXPR as valid expression.
> * tree-ssa-operands: Adjust.
>
> gcc/config/i386
> * sse.md: (sseshuffint) New mode_attr. Correspondence between the
> vector and the type of the mask when shuffling.
> (vecshuffle<mode>): New expansion.
> * i386-protos.h (ix86_expand_vshuffle): New prototype.
> * i386.c (ix86_expand_vshuffle): Expand vshuffle using pshufb.
> (ix86_vectorize_builtin_vec_perm_ok): Adjust.
>
> gcc/doc
> * extend.texi: Adjust.
>
> gcc/testsuite
> * gcc.c-torture/execute/vect-shuffle-2.c: New test.
> * gcc.c-torture/execute/vect-shuffle-4.c: New test.
> * gcc.c-torture/execute/vect-shuffle-1.c: New test.
> * gcc.c-torture/execute/vect-shuffle-3.c: New test.
>
> bootstrapped on x86_64-unknown-linux-gnu. The AVX parts are not
> tested, because I don't have actual hardware. It works with -mavx, the
> assembler code looks fine to me. I'll test it on a real hardware in
> couple of days.
>
>
>
> Thanks,
> Artem Shinkarov.
>
