PR: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112438
SELECT_VL result is not necessary always VF in non-final iteration.
Current GIMPLE IR is wrong:
# vect_vec_iv_.21_25 = PHI <_24(4), { 0, 1, 2, ... }(3)>
...
_24 = vect_vec_iv_.21_25 + { POLY_INT_CST [4, 4], ... };
After this patch which is correct for SELECT_VL:
# vect_vec_iv_.8_22 = PHI <_21(4), { 0, 1, 2, ... }(3)>
...
_35 = .SELECT_VL (ivtmp_33, POLY_INT_CST [4, 4]);
_21 = vect_vec_iv_.8_22 + { POLY_INT_CST [4, 4], ... };
kito, could you give more explanation ?
PR middle/112438
gcc/ChangeLog:
* tree-vect-loop.cc (vectorizable_induction): Fix bug.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/autovec/pr112438.c: New test.
---
.../gcc.target/riscv/rvv/autovec/pr112438.c | 35 +++++++++++++++++
gcc/tree-vect-loop.cc | 39 +++++++++++++++----
2 files changed, 67 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112438.c
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112438.c
b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112438.c
new file mode 100644
index 00000000000..b326d56a52c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112438.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -fno-vect-cost-model
-ffast-math -fdump-tree-optimized-details" } */
+
+void
+foo (int n, int *__restrict in, int *__restrict out)
+{
+ for (int i = 0; i < n; i += 1)
+ {
+ out[i] = in[i] + i;
+ }
+}
+
+void
+foo2 (int n, float * __restrict in,
+float * __restrict out)
+{
+ for (int i = 0; i < n; i += 1)
+ {
+ out[i] = in[i] + i;
+ }
+}
+
+void
+foo3 (int n, float * __restrict in,
+float * __restrict out, float x)
+{
+ for (int i = 0; i < n; i += 1)
+ {
+ out[i] = in[i] + i* i;
+ }
+}
+
+/* We don't want to see vect_vec_iv_.21_25 + { POLY_INT_CST [4, 4], ... }. */
+/* { dg-final { scan-tree-dump-not "\\+ \{ POLY_INT_CST" "optimized" } } */
+
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index a544bc9b059..3e103946168 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -10309,10 +10309,30 @@ vectorizable_induction (loop_vec_info loop_vinfo,
new_name = step_expr;
else
{
+ gimple_seq seq = NULL;
+ if (LOOP_VINFO_USING_SELECT_VL_P (loop_vinfo))
+ {
+ /* When we're using loop_len produced by SELEC_VL, the non-final
+ iterations are not always processing VF elements. So vectorize
+ induction variable instead of
+
+ _21 = vect_vec_iv_.6_22 + { VF, ... };
+
+ We should generate:
+
+ _35 = .SELECT_VL (ivtmp_33, VF);
+ vect_cst__22 = [vec_duplicate_expr] _35;
+ _21 = vect_vec_iv_.6_22 + vect_cst__22; */
+ vec_loop_lens *lens = &LOOP_VINFO_LENS (loop_vinfo);
+ tree len
+ = vect_get_loop_len (loop_vinfo, NULL, lens, 1, vectype, 0, 0);
+ expr = force_gimple_operand (fold_convert (TREE_TYPE (step_expr),
+ unshare_expr (len)),
+ &seq, true, NULL_TREE);
+ }
/* iv_loop is the loop to be vectorized. Generate:
vec_step = [VF*S, VF*S, VF*S, VF*S] */
- gimple_seq seq = NULL;
- if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr)))
+ else if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr)))
{
expr = build_int_cst (integer_type_node, vf);
expr = gimple_build (&seq, FLOAT_EXPR, TREE_TYPE (step_expr), expr);
@@ -10323,8 +10343,13 @@ vectorizable_induction (loop_vec_info loop_vinfo,
expr, step_expr);
if (seq)
{
- new_bb = gsi_insert_seq_on_edge_immediate (pe, seq);
- gcc_assert (!new_bb);
+ if (LOOP_VINFO_USING_SELECT_VL_P (loop_vinfo))
+ gsi_insert_seq_before (&si, seq, GSI_SAME_STMT);
+ else
+ {
+ new_bb = gsi_insert_seq_on_edge_immediate (pe, seq);
+ gcc_assert (!new_bb);
+ }
}
}
@@ -10332,9 +10357,9 @@ vectorizable_induction (loop_vec_info loop_vinfo,
gcc_assert (CONSTANT_CLASS_P (new_name)
|| TREE_CODE (new_name) == SSA_NAME);
new_vec = build_vector_from_val (step_vectype, t);
- vec_step = vect_init_vector (loop_vinfo, stmt_info,
- new_vec, step_vectype, NULL);
-
+ vec_step
+ = vect_init_vector (loop_vinfo, stmt_info, new_vec, step_vectype,
+ LOOP_VINFO_USING_SELECT_VL_P (loop_vinfo) ? &si : NULL);
/* Create the following def-use cycle:
loop prolog:
--
2.36.3
