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Re: Fold vector to scalar optimization
Here is a version with the fixes.
ChangeLog:
2010-11-01 Artjoms Sinkarovs <artyom.shinakroff@gmail.com>
gcc/
* passes.c (init_optimization_passes): Move veclower after SSA.
* tree-vect-generic.c (expand_vector_operations_1): Handle conversion.
gcc/testsuite/
* gcc.dg/vec-scal-opt.c: New testcase.
* gcc.dg/vec-scal-opt1.c: New testcase.
* gcc.dg/vec-scal-opt2.c: New testcase.
bootstrapped and tested on x86_64_unknown-linux
Ok?
On Tue, Nov 2, 2010 at 11:03 AM, Richard Guenther
<richard.guenther@gmail.com> wrote:
> On Mon, Nov 1, 2010 at 9:11 PM, Artem Shinkarov
> <artyom.shinkaroff@gmail.com> wrote:
>> This patch folds a vector of equal values to the scalar in
>> vector-shift operation.
>>
>> ChangeLog:
>>
>> 2010-11-01 ?Artjoms Sinkarovs <artyom.shinakroff@gmail.com>
>>
>> ? ? gcc/
>> ? ? * passes.c (init_optimization_passes): Move veclower after SSA.
>> ? ? * tree-vect-generic.c (expand_vector_operations_1): Handle conversion.
>>
>> ? ? gcc/testsuite/
>> ? ? * gcc.dg/vec-scal-opt.c: New testcase.
>> ? ? * gcc.dg/vec-scal-opt1.c: New testcase.
>> ? ? * gcc.dg/vec-scal-opt2.c: New testcase.
>>
>>
>> bootstrapped and tested on x86_64_unknown-linux
>>
>> OK?
>
> @@ -436,8 +436,72 @@ expand_vector_operations_1 (gimple_stmt_
> ? ? {
> ? ? ? /* If the 2nd argument is vector, we need a vector/vector shift */
> ? ? ? if (VECTOR_MODE_P (TYPE_MODE (TREE_TYPE (rhs2))))
> - ? ? ? op = optab_for_tree_code (code, type, optab_vector);
> - ? ? ?else
> + ? ? ? ?{
> + ? ? ? ? ?/* Chack whether we have vector <op> {x,x,x,x} where x
>
> Typo. ?'Check'
>
> + ? ? ? ? ? ? could be a scalar variable or a constant. Transform
> + ? ? ? ? ? ? vector <op> {x,x,x,x} ==> vector <op> scalar. ?*/
> + ? ? ? ? ?if (TREE_CODE (rhs2) == SSA_NAME
> + ? ? ? ? ? ? ?&& TREE_CODE (TREE_TYPE (rhs2)) == VECTOR_TYPE)
>
> So this misses the case when rhs2 is a VECTOR_CST. ?Also in
> case we have such a constant vector but then no support for
> vector <<>> scalar we wil expand it again. ?So I think it's better
> to check the two case up-front and only rewrite the shift operand
> if the scalar variant is supported.
>
> For less gratious indents please split recognizing a vector with
> all the same elements into a separate function like
> bool uniform_vector_p (tree vector).
>
> Thanks,
> Richard.
>
Index: gcc/testsuite/gcc.dg/vec-scal-opt2.c
===================================================================
--- gcc/testsuite/gcc.dg/vec-scal-opt2.c (revision 0)
+++ gcc/testsuite/gcc.dg/vec-scal-opt2.c (revision 0)
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-veclower" } */
+
+#define vidx(type, vec, idx) (*((type *) &(vec) + idx))
+#define vector(elcount, type) \
+__attribute__((vector_size((elcount)*sizeof(type)))) type
+
+int main (int argc, char *argv[]) {
+ vector(8, short) v0 = {argc,1,2,3,4,5,6,7};
+ vector(8, short) v1 = {2,2,2,2,2,2,2,2};
+ vector(8, short) r1;
+
+ r1 = v0 >> v1;
+
+ return vidx(short, r1, 0);
+}
+
+/* { dg-final { scan-tree-dump-times ">> 2" 1 "veclower" } } */
+/* { dg-final { cleanup-tree-dump "veclower" } } */
Index: gcc/testsuite/gcc.dg/vec-scal-opt.c
===================================================================
--- gcc/testsuite/gcc.dg/vec-scal-opt.c (revision 0)
+++ gcc/testsuite/gcc.dg/vec-scal-opt.c (revision 0)
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-veclower" } */
+
+#define vidx(type, vec, idx) (*((type *) &(vec) + idx))
+#define vector(elcount, type) \
+__attribute__((vector_size((elcount)*sizeof(type)))) type
+
+short k;
+
+int main (int argc, char *argv[]) {
+ k = argc;
+ vector(8, short) v0 = {argc,1,2,3,4,5,6,7};
+ vector(8, short) v2 = {k, k,k,k,k,k,k,k};
+ vector(8, short) r1;
+
+ r1 = v0 >> v2;
+
+ return vidx(short, r1, 0);
+}
+
+/* { dg-final { scan-tree-dump-times ">> k.\[0-9_\]*" 1 "veclower" } } */
+/* { dg-final { cleanup-tree-dump "veclower" } } */
Index: gcc/testsuite/gcc.dg/vec-scal-opt1.c
===================================================================
--- gcc/testsuite/gcc.dg/vec-scal-opt1.c (revision 0)
+++ gcc/testsuite/gcc.dg/vec-scal-opt1.c (revision 0)
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-veclower" } */
+
+#define vidx(type, vec, idx) (*((type *) &(vec) + idx))
+#define vector(elcount, type) \
+__attribute__((vector_size((elcount)*sizeof(type)))) type
+
+short k;
+
+int main (int argc, char *argv[]) {
+ vector(8, short) v0 = {argc,1,2,3,4,5,6,7};
+ vector(8, short) r1;
+
+ r1 = v0 >> (vector(8, short)){2,2,2,2,2,2,2,2};
+
+ return vidx(short, r1, 0);
+}
+
+/* { dg-final { scan-tree-dump-times ">> 2" 1 "veclower" } } */
+/* { dg-final { cleanup-tree-dump "veclower" } } */
Index: gcc/tree-vect-generic.c
===================================================================
--- gcc/tree-vect-generic.c (revision 166126)
+++ gcc/tree-vect-generic.c (working copy)
@@ -284,6 +284,58 @@ expand_vector_addition (gimple_stmt_iter
a, b, code);
}
+/* Check if vector VEC consists of all the equal elements and
+ that the number of elements corresponds to the type of VEC.
+ Function sets ELEMENT with the first element of the vector
+ or NULL_TREE if comparison failed. */
+static bool uniform_vector_p (tree vec, tree *element)
+{
+ tree first, t, els;
+ bool eq = true;
+ unsigned HOST_WIDE_INT i;
+
+ *element = NULL_TREE;
+
+ if (vec == NULL_TREE)
+ return false;
+
+ if (TREE_CODE (vec) == VECTOR_CST)
+ {
+ els = TREE_VECTOR_CST_ELTS (vec);
+ first = TREE_VALUE (els);
+ els = TREE_CHAIN (els);
+
+ for (t = els, i = 0; t; t = TREE_CHAIN (t), i++)
+ if (!(eq = operand_equal_p (first, TREE_VALUE(t), 0)))
+ break;
+
+ *element = first;
+ return eq && (i == TYPE_VECTOR_SUBPARTS (TREE_TYPE (vec))-1);
+ }
+
+ else if (TREE_CODE (vec) == CONSTRUCTOR)
+ {
+ first = error_mark_node;
+
+ FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (vec), i, t)
+ {
+ if (i == 0)
+ {
+ first = t;
+ continue;
+ }
+ if (!(eq = (first == t)))
+ break;
+ }
+
+ *element = first;
+ return eq && (i == TYPE_VECTOR_SUBPARTS (TREE_TYPE (vec)));
+
+ }
+
+ return false;
+}
+
static tree
expand_vector_operation (gimple_stmt_iterator *gsi, tree type, tree compute_type,
gimple assign, enum tree_code code)
@@ -392,7 +444,7 @@ expand_vector_operations_1 (gimple_stmt_
tree lhs, rhs1, rhs2 = NULL, type, compute_type;
enum tree_code code;
enum machine_mode compute_mode;
- optab op;
+ optab op = NULL;
enum gimple_rhs_class rhs_class;
tree new_rhs;
@@ -434,18 +486,44 @@ expand_vector_operations_1 (gimple_stmt_
|| code == LROTATE_EXPR
|| code == RROTATE_EXPR)
{
- /* If the 2nd argument is vector, we need a vector/vector shift */
+ bool vector_scalar_shift;
+ op = optab_for_tree_code (code, type, optab_scalar);
+ /* Vector/Scalar shift is supported. */
+ vector_scalar_shift = !(!op
+ || optab_handler (op, TYPE_MODE (type))
+ == CODE_FOR_nothing);
+
+ /* If the 2nd argument is vector, we need a vector/vector shift.
+ Except all the elements in the second vector are the same. */
if (VECTOR_MODE_P (TYPE_MODE (TREE_TYPE (rhs2))))
- op = optab_for_tree_code (code, type, optab_vector);
- else
- {
- /* Try for a vector/scalar shift, and if we don't have one, see if we
- have a vector/vector shift */
- op = optab_for_tree_code (code, type, optab_scalar);
- if (!op
- || optab_handler (op, TYPE_MODE (type)) == CODE_FOR_nothing)
- op = optab_for_tree_code (code, type, optab_vector);
- }
+ {
+ tree first, var = NULL_TREE;
+ gimple def_stmt;
+
+ /* Check whether we have vector <op> {x,x,x,x} where x
+ could be a scalar variable or a constant. Transform
+ vector <op> {x,x,x,x} ==> vector <op> scalar. */
+ if (vector_scalar_shift
+ && ((TREE_CODE (rhs2) == VECTOR_CST && (var = rhs2))
+ ||
+ (TREE_CODE (rhs2) == SSA_NAME
+ && (def_stmt = SSA_NAME_DEF_STMT (rhs2))
+ && gimple_assign_single_p (def_stmt)
+ && (var = gimple_assign_rhs1 (def_stmt))))
+ && uniform_vector_p (var, &first))
+ {
+ gimple_assign_set_rhs2 (stmt, first);
+ update_stmt (stmt);
+ rhs2 = first;
+ }
+ else
+ op = optab_for_tree_code (code, type, optab_vector);
+ }
+
+ /* Try for a vector/scalar shift, and if we don't have one, see if we
+ have a vector/vector shift */
+ else if (!vector_scalar_shift)
+ op = optab_for_tree_code (code, type, optab_vector);
}
else
op = optab_for_tree_code (code, type, optab_default);
Index: gcc/passes.c
===================================================================
--- gcc/passes.c (revision 166126)
+++ gcc/passes.c (working copy)
@@ -736,7 +736,6 @@ init_optimization_passes (void)
NEXT_PASS (pass_refactor_eh);
NEXT_PASS (pass_lower_eh);
NEXT_PASS (pass_build_cfg);
- NEXT_PASS (pass_lower_vector);
NEXT_PASS (pass_warn_function_return);
NEXT_PASS (pass_build_cgraph_edges);
NEXT_PASS (pass_inline_parameters);
@@ -755,6 +754,7 @@ init_optimization_passes (void)
NEXT_PASS (pass_referenced_vars);
NEXT_PASS (pass_build_ssa);
+ NEXT_PASS (pass_lower_vector);
NEXT_PASS (pass_early_warn_uninitialized);
/* Note that it is not strictly necessary to schedule an early
inline pass here. However, some test cases (e.g.,