From: Juzhe-Zhong <[email protected]>
This patch is to enhance optimization for auto-vectorization.
Before this patch:
Loop:
vsetvl a5,a2...
vsetvl zero,a5...
vle
After this patch:
Loop:
vsetvl a5,a2
vle
gcc/ChangeLog:
* config/riscv/riscv-vsetvl.cc (local_eliminate_vsetvl_insn): New
function.
(vector_insn_info::skip_avl_compatible_p): Ditto.
(vector_insn_info::merge): Remove default value.
(pass_vsetvl::compute_local_backward_infos): Ditto.
(pass_vsetvl::cleanup_insns): Add local vsetvl elimination.
* config/riscv/riscv-vsetvl.h: Ditto.
---
gcc/config/riscv/riscv-vsetvl.cc | 71 +++++++++++++++++++++++++++++++-
gcc/config/riscv/riscv-vsetvl.h | 1 +
2 files changed, 70 insertions(+), 2 deletions(-)
diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 7e8a5376705..b402035f7a5 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -1054,6 +1054,51 @@ change_vsetvl_insn (const insn_info *insn, const
vector_insn_info &info)
change_insn (rinsn, new_pat);
}
+static void
+local_eliminate_vsetvl_insn (const vector_insn_info &dem)
+{
+ const insn_info *insn = dem.get_insn ();
+ if (!insn || insn->is_artificial ())
+ return;
+ rtx_insn *rinsn = insn->rtl ();
+ const bb_info *bb = insn->bb ();
+ if (vsetvl_insn_p (rinsn))
+ {
+ rtx vl = get_vl (rinsn);
+ for (insn_info *i = insn->next_nondebug_insn ();
+ real_insn_and_same_bb_p (i, bb); i = i->next_nondebug_insn ())
+ {
+ if (i->is_call () || i->is_asm ()
+ || find_access (i->defs (), VL_REGNUM)
+ || find_access (i->defs (), VTYPE_REGNUM))
+ return;
+
+ if (has_vtype_op (i->rtl ()))
+ {
+ if (!vsetvl_discard_result_insn_p (PREV_INSN (i->rtl ())))
+ return;
+ rtx avl = get_avl (i->rtl ());
+ if (avl != vl)
+ return;
+ set_info *def = find_access (i->uses (), REGNO (avl))->def ();
+ if (def->insn () != insn)
+ return;
+
+ vector_insn_info new_info;
+ new_info.parse_insn (i);
+ if (!new_info.skip_avl_compatible_p (dem))
+ return;
+
+ new_info.set_avl_info (dem.get_avl_info ());
+ new_info = dem.merge (new_info, LOCAL_MERGE);
+ change_vsetvl_insn (insn, new_info);
+ eliminate_insn (PREV_INSN (i->rtl ()));
+ return;
+ }
+ }
+ }
+}
+
static bool
source_equal_p (insn_info *insn1, insn_info *insn2)
{
@@ -1984,6 +2029,19 @@ vector_insn_info::compatible_p (const vector_insn_info
&other) const
return true;
}
+bool
+vector_insn_info::skip_avl_compatible_p (const vector_insn_info &other) const
+{
+ gcc_assert (valid_or_dirty_p () && other.valid_or_dirty_p ()
+ && "Can't compare invalid demanded infos");
+ unsigned array_size = sizeof (incompatible_conds) / sizeof (demands_cond);
+ /* Bypass AVL incompatible cases. */
+ for (unsigned i = 1; i < array_size; i++)
+ if (incompatible_conds[i].dual_incompatible_p (*this, other))
+ return false;
+ return true;
+}
+
bool
vector_insn_info::compatible_avl_p (const vl_vtype_info &other) const
{
@@ -2178,7 +2236,7 @@ vector_insn_info::fuse_mask_policy (const
vector_insn_info &info1,
vector_insn_info
vector_insn_info::merge (const vector_insn_info &merge_info,
- enum merge_type type = LOCAL_MERGE) const
+ enum merge_type type) const
{
if (!vsetvl_insn_p (get_insn ()->rtl ()))
gcc_assert (this->compatible_p (merge_info)
@@ -2716,7 +2774,7 @@ pass_vsetvl::compute_local_backward_infos (const bb_info
*bb)
&& !reg_available_p (insn, change))
&& change.compatible_p (info))
{
- info = change.merge (info);
+ info = change.merge (info, LOCAL_MERGE);
/* Fix PR109399, we should update user vsetvl instruction
if there is a change in demand fusion. */
if (vsetvl_insn_p (insn->rtl ()))
@@ -3998,6 +4056,15 @@ pass_vsetvl::cleanup_insns (void) const
for (insn_info *insn : bb->real_nondebug_insns ())
{
rtx_insn *rinsn = insn->rtl ();
+ const auto &dem = m_vector_manager->vector_insn_infos[insn->uid ()];
+ /* Eliminate local vsetvl:
+ bb 0:
+ vsetvl a5,a6,...
+ vsetvl zero,a5.
+
+ Eliminate vsetvl in bb2 when a5 is only coming from
+ bb 0. */
+ local_eliminate_vsetvl_insn (dem);
if (vlmax_avl_insn_p (rinsn))
{
diff --git a/gcc/config/riscv/riscv-vsetvl.h b/gcc/config/riscv/riscv-vsetvl.h
index d05472c86a0..d7a6c14e931 100644
--- a/gcc/config/riscv/riscv-vsetvl.h
+++ b/gcc/config/riscv/riscv-vsetvl.h
@@ -380,6 +380,7 @@ public:
void fuse_mask_policy (const vector_insn_info &, const vector_insn_info &);
bool compatible_p (const vector_insn_info &) const;
+ bool skip_avl_compatible_p (const vector_insn_info &) const;
bool compatible_avl_p (const vl_vtype_info &) const;
bool compatible_avl_p (const avl_info &) const;
bool compatible_vtype_p (const vl_vtype_info &) const;
--
2.36.3
