https://gcc.gnu.org/g:de1389e24e8dc98b65bc8d40976172214ac4ecc0
commit r15-3689-gde1389e24e8dc98b65bc8d40976172214ac4ecc0
Author: Richard Biener <rguent...@suse.de>
Date: Sun Sep 8 11:21:19 2024 +0200
Fail vectorization when not using SLP and --param vect-force-slp == 1
The following adds --param vect-force-slp to enable the transition
to full SLP. Full SLP is enforced during stmt analysis where it
detects failed SLP discovery and at loop analysis time where it
avoids analyzing a loop with SLP disabled. Failure to SLP results
in vectorization to fail.
* params.opt (vect-force-slp): New param, default 0.
* doc/invoke.texi (--param vect-force-slp): Document.
* tree-vect-loop.cc (vect_analyze_loop_2): When analyzing
without SLP but --param vect-force-slp is 1 fail.
* tree-vect-stmts.cc (vect_analyze_stmt): Fail vectorization
for non-SLP stmts when --param vect-force-slp is 1.
Diff:
---
gcc/doc/invoke.texi | 3 +++
gcc/params.opt | 4 ++++
gcc/tree-vect-loop.cc | 6 ++++++
gcc/tree-vect-stmts.cc | 6 ++++++
4 files changed, 19 insertions(+)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 511b8c8d3111..b91fb9c9cca6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -16955,6 +16955,9 @@ this parameter. The default value of this parameter is
50.
@item vect-induction-float
Enable loop vectorization of floating point inductions.
+@item vect-force-slp
+Force the use of SLP when vectorizing, fail if not possible.
+
@item vrp-block-limit
Maximum number of basic blocks before VRP switches to a lower memory algorithm.
diff --git a/gcc/params.opt b/gcc/params.opt
index c17ba17b91b0..949b47544980 100644
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -1198,6 +1198,10 @@ The maximum factor which the loop vectorizer applies to
the cost of statements i
Common Joined UInteger Var(param_vect_induction_float) Init(1) IntegerRange(0,
1) Param Optimization
Enable loop vectorization of floating point inductions.
+-param=vect-force-slp=
+Common Joined UInteger Var(param_vect_force_slp) Init(0) IntegerRange(0, 1)
Param Optimization
+Force the use of SLP when vectorizing, fail if not possible.
+
-param=vrp-block-limit=
Common Joined UInteger Var(param_vrp_block_limit) Init(150000) Optimization
Param
Maximum number of basic blocks before VRP switches to a fast model with less
memory requirements.
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 62c7f90779fa..d42694d19747 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -2891,6 +2891,12 @@ vect_analyze_loop_2 (loop_vec_info loop_vinfo, bool
&fatal,
/* This is the point where we can re-start analysis with SLP forced off. */
start_over:
+ /* When we arrive here with SLP disabled and we are supposed
+ to use SLP for everything fail vectorization. */
+ if (!slp && param_vect_force_slp)
+ return opt_result::failure_at (vect_location,
+ "may need non-SLP handling\n");
+
/* Apply the suggested unrolling factor, this was determined by the backend
during finish_cost the first time we ran the analyzis for this
vector mode. */
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index b1353c91fce1..495f45e40e63 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -13353,6 +13353,12 @@ vect_analyze_stmt (vec_info *vinfo,
return opt_result::success ();
}
+ /* When we arrive here with a non-SLP statement and we are supposed
+ to use SLP for everything fail vectorization. */
+ if (!node && param_vect_force_slp)
+ return opt_result::failure_at (stmt_info->stmt,
+ "needs non-SLP handling\n");
+
ok = true;
if (!bb_vinfo
&& (STMT_VINFO_RELEVANT_P (stmt_info)
