Currently, simplify_vector_constructor () tries to rewrite a CONSTRUCTOR
expression into a VEC_PERM_EXPR, as long as constructor elements all come
from 1 or 2 source vectors. While doing so, it protects against creating
VEC_PERM_EXPRs unsupported by the target by calling can_vec_perm_const_p
() before enacting the transformation and bailing when that returns false.
However, we can instead allow those VEC_PERM_EXPRs to be created if we
know that a later vector lowering pass will legitimize them for us. IOW,
only if the target doesn't support the resulting permute and the
PROP_gimple_lvec property is already set, do we give up. This patch
inserts the required checks.
This also allows us to remove the unnecessary vect_int requirement
(wrongly added in r16-5244-g5a2319b71e4d30) from forwprop-43.c.
Regtested on aarch64 and x86_64, and on arm with
RUNTESTFLAGS=--target_board=unix/-mfpu=vfpv3-d16/-march=armv7-a.
PR tree-optimization/122679
gcc/ChangeLog:
* tree-ssa-forwprop.cc (simplify_vector_constructor): Check the
PROP_gimple_lvec property before bailing.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/forwprop-43.c: Remove the vect_int check.
---
gcc/testsuite/gcc.dg/tree-ssa/forwprop-43.c | 1 -
gcc/tree-ssa-forwprop.cc | 6 ++++--
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/forwprop-43.c
b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-43.c
index bfda376e1f7..0e802ea5107 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/forwprop-43.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-43.c
@@ -1,7 +1,6 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-forwprop1" } */
/* { dg-require-effective-target stdint_types } */
-/* { dg-require-effective-target vect_int } */
/* { dg-additional-options "-fgimple" } */
#include <stdint.h>
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index bdc63a7a71b..6c847ee7ff3 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -4173,7 +4173,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
? 0 : refnelts) + i);
vec_perm_indices indices (sel, orig[1] ? 2 : 1, refnelts);
machine_mode vmode = TYPE_MODE (perm_type);
- if (!can_vec_perm_const_p (vmode, vmode, indices))
+ if (!can_vec_perm_const_p (vmode, vmode, indices)
+ && (cfun->curr_properties & PROP_gimple_lvec))
return false;
mask_type = build_vector_type (ssizetype, refnelts);
tree op2 = vec_perm_indices_to_tree (mask_type, indices);
@@ -4238,7 +4239,8 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
? elts[i].second + nelts : i);
vec_perm_indices indices (sel, 2, nelts);
machine_mode vmode = TYPE_MODE (type);
- if (!can_vec_perm_const_p (vmode, vmode, indices))
+ if (!can_vec_perm_const_p (vmode, vmode, indices)
+ && (cfun->curr_properties & PROP_gimple_lvec))
return false;
mask_type = build_vector_type (ssizetype, nelts);
blend_op2 = vec_perm_indices_to_tree (mask_type, indices);
--
2.43.0
