This patch is depending on LEN_MASK_{LOAD,STORE} patch:
https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622742.html
After enabling the LEN_MASK_{LOAD,STORE}, I notice that there is a case that
VSETVL PASS need to be optimized:
void
f (int32_t *__restrict a,
int32_t *__restrict b,
int32_t *__restrict cond,
int n)
{
for (int i = 0; i < 8; i++)
if (cond[i])
a[i] = b[i];
}
Before this patch:
f:
vsetivli a5,8,e8,mf4,tu,mu --> Propagate "8" to the following
vsetvl
vsetvli zero,a5,e32,m1,ta,ma
vle32.v v0,0(a2)
vsetvli a6,zero,e32,m1,ta,ma
li a3,8
vmsne.vi v0,v0,0
vsetvli zero,a5,e32,m1,ta,ma
vle32.v v1,0(a1),v0.t
vse32.v v1,0(a0),v0.t
sub a4,a3,a5
beq a3,a5,.L6
slli a5,a5,2
add a2,a2,a5
add a1,a1,a5
add a0,a0,a5
vsetvli a5,a4,e8,mf4,tu,mu --> Propagate "a4" to the following
vsetvl
vsetvli zero,a5,e32,m1,ta,ma
vle32.v v0,0(a2)
vsetvli a6,zero,e32,m1,ta,ma
vmsne.vi v0,v0,0
vsetvli zero,a5,e32,m1,ta,ma
vle32.v v1,0(a1),v0.t
vse32.v v1,0(a0),v0.t
.L6:
ret
Current VSETLV PASS only enable AVL propagation of VLMAX AVL ("zero").
Now, we enable AVL propagation of immediate && conservative non-VLMAX.
After this patch:
f:
vsetivli a5,8,e8,mf4,ta,ma
vle32.v v0,0(a2)
vsetvli a6,zero,e32,m1,ta,ma
li a3,8
vmsne.vi v0,v0,0
vsetivli zero,8,e32,m1,ta,ma
vle32.v v1,0(a1),v0.t
vse32.v v1,0(a0),v0.t
sub a4,a3,a5
beq a3,a5,.L6
slli a5,a5,2
vsetvli a4,a4,e8,mf4,ta,ma
add a2,a2,a5
vle32.v v0,0(a2)
add a1,a1,a5
vsetvli a6,zero,e32,m1,ta,ma
add a0,a0,a5
vmsne.vi v0,v0,0
vsetvli zero,a4,e32,m1,ta,ma
vle32.v v1,0(a1),v0.t
vse32.v v1,0(a0),v0.t
.L6:
ret
gcc/ChangeLog:
* config/riscv/riscv-vsetvl.cc (vector_insn_info::parse_insn): Ehance
AVL propagation.
* config/riscv/riscv-vsetvl.h: New function.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/autovec/partial/select_vl-1.c: Add dump checks.
* gcc.target/riscv/rvv/autovec/partial/select_vl-2.c: New test.
---
gcc/config/riscv/riscv-vsetvl.cc | 48 +++++++++++++++++--
gcc/config/riscv/riscv-vsetvl.h | 2 +
.../riscv/rvv/autovec/partial/select_vl-1.c | 5 +-
.../riscv/rvv/autovec/partial/select_vl-2.c | 25 ++++++++++
4 files changed, 76 insertions(+), 4 deletions(-)
create mode 100644
gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-2.c
diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 971c3f90742..2d576e8d5c1 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -2003,9 +2003,51 @@ vector_insn_info::parse_insn (insn_info *insn)
new_info.parse_insn (def_insn);
if (!same_vlmax_p (new_info) && !scalar_move_insn_p (insn->rtl ()))
return;
- /* TODO: Currently, we don't forward AVL for non-VLMAX vsetvl. */
- if (vlmax_avl_p (new_info.get_avl ()))
- set_avl_info (avl_info (new_info.get_avl (), get_avl_source ()));
+
+ if (new_info.has_avl ())
+ {
+ if (new_info.has_avl_imm ())
+ set_avl_info (avl_info (new_info.get_avl (), nullptr));
+ else
+ {
+ if (vlmax_avl_p (new_info.get_avl ()))
+ set_avl_info (avl_info (new_info.get_avl (), get_avl_source ()));
+ else
+ {
+ /* Conservatively propagate non-VLMAX AVL of user vsetvl:
+ 1. The user vsetvl should be same block with the rvv insn.
+ 2. The user vsetvl is the only def insn of rvv insn.
+ 3. The AVL is not modified between def-use chain.
+ 4. The VL is only used by insn within EBB.
+ */
+ bool modified_p = false;
+ for (insn_info *i = def_insn->next_nondebug_insn ();
+ real_insn_and_same_bb_p (i, get_insn ()->bb ());
+ i = i->next_nondebug_insn ())
+ {
+ if (find_access (i->defs (), REGNO (new_info.get_avl ())))
+ {
+ modified_p = true;
+ break;
+ }
+ }
+
+ bool has_live_out_use = false;
+ for (use_info *use : m_avl.get_source ()->all_uses ())
+ {
+ if (use->is_live_out_use ())
+ {
+ has_live_out_use = true;
+ break;
+ }
+ }
+ if (!modified_p && !has_live_out_use
+ && def_insn == m_avl.get_source ()->insn ()
+ && m_insn->bb () == def_insn->bb ())
+ set_avl_info (new_info.get_avl_info ());
+ }
+ }
+ }
if (scalar_move_insn_p (insn->rtl ()) && m_avl.has_non_zero_avl ())
m_demands[DEMAND_NONZERO_AVL] = true;
diff --git a/gcc/config/riscv/riscv-vsetvl.h b/gcc/config/riscv/riscv-vsetvl.h
index 4257451bb74..87cdd2e886e 100644
--- a/gcc/config/riscv/riscv-vsetvl.h
+++ b/gcc/config/riscv/riscv-vsetvl.h
@@ -180,6 +180,7 @@ public:
bool has_avl_reg () const { return get_value () && REG_P (get_value ()); }
bool has_avl_no_reg () const { return !get_value (); }
bool has_non_zero_avl () const;
+ bool has_avl () const { return get_value (); }
};
/* Basic structure to save VL/VTYPE information. */
@@ -219,6 +220,7 @@ public:
bool has_avl_reg () const { return m_avl.has_avl_reg (); }
bool has_avl_no_reg () const { return m_avl.has_avl_no_reg (); }
bool has_non_zero_avl () const { return m_avl.has_non_zero_avl (); };
+ bool has_avl () const { return m_avl.has_avl (); }
rtx get_avl () const { return m_avl.get_value (); }
const avl_info &get_avl_info () const { return m_avl; }
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-1.c
b/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-1.c
index 74bbf40ee9f..e27090d79cf 100644
--- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-1.c
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-1.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-additional-options "-march=rv32gcv -mabi=ilp32d --param
riscv-autovec-preference=scalable -fno-vect-cost-model
-fno-tree-loop-distribute-patterns -fdump-tree-optimized-details" } */
+/* { dg-additional-options "-march=rv32gcv_zvfh -mabi=ilp32d --param
riscv-autovec-preference=scalable -fno-vect-cost-model
-fno-tree-loop-distribute-patterns -fdump-tree-optimized-details" } */
#include <stdint-gcc.h>
@@ -20,7 +20,10 @@
TEST_TYPE (uint32_t)
\
TEST_TYPE (int64_t)
\
TEST_TYPE (uint64_t)
\
+ TEST_TYPE (_Float16)
\
TEST_TYPE (float)
\
TEST_TYPE (double)
TEST_ALL ()
+
+/* { dg-final { scan-tree-dump-times "\.SELECT_VL" 11 "optimized" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-2.c
b/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-2.c
new file mode 100644
index 00000000000..eac7cbc757b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-2.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d --param
riscv-autovec-preference=scalable -fno-schedule-insns --param
riscv-autovec-lmul=m1 -O3 -ftree-vectorize" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#include <stdint-gcc.h>
+
+/*
+** foo:
+**
vsetivli\t[a-x0-9]+,\s*8,\s*e(8?|16?|32?|64),\s*m(1?|2?|4?|8?|f2?|f4?|f8),\s*t[au],\s*m[au]
+** vle32\.v\tv[0-9]+,0\([a-x0-9]+\)
+** ...
+**
vsetvli\t[a-x0-9]+,\s*[a-x0-9]+,\s*e(8?|16?|32?|64),\s*m(1?|2?|4?|8?|f2?|f4?|f8),\s*t[au],\s*m[au]
+** add\t[a-x0-9]+,[a-x0-9]+,[a-x0-9]+
+** vle32\.v\tv[0-9]+,0\([a-x0-9]+\)
+** ...
+*/
+void
+foo (int32_t *__restrict a,
+ int32_t *__restrict b,
+ int32_t *__restrict cond)
+{
+ for (int i = 0; i < 8; i++)
+ if (cond[i])
+ a[i] = b[i];
+}
--
2.36.1
