https://gcc.gnu.org/g:0907a810f586b07636cc5b83dba6025eb5240655
commit r16-54-g0907a810f586b07636cc5b83dba6025eb5240655
Author: Jan Hubicka <hubi...@ucw.cz>
Date: Mon Apr 21 20:16:50 2025 +0200
Fix cost of vectorized double->float conversion
In previous patch I miscomputed costs of cvtpd2pf instruction
which mistakely gets accounted as 2 (VEC_PACK_TRUNC_EXPR).
Vectorizer can produce both, but when producing VEC_PACK_TRUNC_EXPR
it use promote_demote patch. This patch thus simplifies
handling of NOP_EXPR since in that case we should always be producing
only one instruction.
PR target/119879
* config/i386/i386.cc (fp_conversion_stmt_cost): Inline to ...
(ix86_vector_costs::add_stmt_cost): ... here; fix handling of
NOP_EXPR.
Diff:
---
gcc/config/i386/i386.cc | 51 +++++++++++++++++++++----------------------------
1 file changed, 22 insertions(+), 29 deletions(-)
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 28603c2943ee..d15f91ddd2cb 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -25257,32 +25257,6 @@ ix86_vectorize_create_costs (vec_info *vinfo, bool
costing_for_scalar)
return new ix86_vector_costs (vinfo, costing_for_scalar);
}
-/* Return cost of statement doing FP conversion. */
-
-static unsigned
-fp_conversion_stmt_cost (machine_mode mode, gimple *stmt, bool scalar_p)
-{
- int outer_size
- = tree_to_uhwi
- (TYPE_SIZE
- (TREE_TYPE (gimple_assign_lhs (stmt))));
- int inner_size
- = tree_to_uhwi
- (TYPE_SIZE
- (TREE_TYPE (gimple_assign_rhs1 (stmt))));
- int stmt_cost = vec_fp_conversion_cost
- (ix86_tune_cost, GET_MODE_BITSIZE (mode));
- /* VEC_PACK_TRUNC_EXPR: If inner size is greater than outer size we will end
- up doing two conversions and packing them. */
- if (!scalar_p && inner_size > outer_size)
- {
- int n = inner_size / outer_size;
- stmt_cost = stmt_cost * n
- + (n - 1) * ix86_vec_cost (mode, ix86_cost->sse_op);
- }
- return stmt_cost;
-}
-
unsigned
ix86_vector_costs::add_stmt_cost (int count, vect_cost_for_stmt kind,
stmt_vec_info stmt_info, slp_tree node,
@@ -25394,8 +25368,8 @@ ix86_vector_costs::add_stmt_cost (int count,
vect_cost_for_stmt kind,
TREE_TYPE (gimple_assign_rhs1 (stmt_info->stmt))))
stmt_cost = 0;
else if (fp)
- stmt_cost = fp_conversion_stmt_cost (mode, stmt_info->stmt,
- scalar_p);
+ stmt_cost = vec_fp_conversion_cost
+ (ix86_tune_cost, GET_MODE_BITSIZE (mode));
break;
case BIT_IOR_EXPR:
@@ -25439,7 +25413,26 @@ ix86_vector_costs::add_stmt_cost (int count,
vect_cost_for_stmt kind,
if (kind == vec_promote_demote
&& fp && FLOAT_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt_info->stmt))))
- stmt_cost = fp_conversion_stmt_cost (mode, stmt_info->stmt, scalar_p);
+ {
+ int outer_size
+ = tree_to_uhwi
+ (TYPE_SIZE
+ (TREE_TYPE (gimple_assign_lhs (stmt_info->stmt))));
+ int inner_size
+ = tree_to_uhwi
+ (TYPE_SIZE
+ (TREE_TYPE (gimple_assign_rhs1 (stmt_info->stmt))));
+ int stmt_cost = vec_fp_conversion_cost
+ (ix86_tune_cost, GET_MODE_BITSIZE (mode));
+ /* VEC_PACK_TRUNC_EXPR: If inner size is greater than outer size we will
end
+ up doing two conversions and packing them. */
+ if (inner_size > outer_size)
+ {
+ int n = inner_size / outer_size;
+ stmt_cost = stmt_cost * n
+ + (n - 1) * ix86_vec_cost (mode, ix86_cost->sse_op);
+ }
+ }
/* If we do elementwise loads into a vector then we are bound by
latency and execution resources for the many scalar loads
