[PATCH] RISC-V: Enable SELECT_VL for RVV

[juzhe.zhong@rivai.ai]

From: Juzhe-Zhong <juzhe.zhong@rivai.ai>

gcc/ChangeLog:

        * config/riscv/autovec.md (select_vl<mode>): New pattern.
        * config/riscv/riscv-protos.h (gen_no_side_effects_vsetvl_rtx): export global.
        * config/riscv/riscv-v.cc (force_vector_length_operand): Ditto.

gcc/testsuite/ChangeLog:

        * gcc.target/riscv/rvv/autovec/ternop/ternop-2.c: Adapt test.
        * gcc.target/riscv/rvv/autovec/ternop/ternop-5.c: Ditto.
        * gcc.target/riscv/rvv/autovec/partial/select_vl-1.c: New test.

---
 gcc/config/riscv/autovec.md                   | 19 +++++++++++++
 gcc/config/riscv/riscv-protos.h               |  1 +
 gcc/config/riscv/riscv-v.cc                   |  2 +-
 .../riscv/rvv/autovec/partial/select_vl-1.c   | 28 +++++++++++++++++++
 .../riscv/rvv/autovec/ternop/ternop-2.c       |  2 +-
 .../riscv/rvv/autovec/ternop/ternop-5.c       |  2 +-
 6 files changed, 51 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-1.c

diff --git a/gcc/config/riscv/autovec.md b/gcc/config/riscv/autovec.md
index 9f4492db23c..c298f069714 100644
--- a/gcc/config/riscv/autovec.md
+++ b/gcc/config/riscv/autovec.md
@@ -18,6 +18,25 @@
 ;; along with GCC; see the file COPYING3.  If not see
 ;; <http://www.gnu.org/licenses/>.
 
+;; =========================================================================
+;; == SELECT_VL
+;; =========================================================================
+
+(define_expand "select_vl<mode>"
+  [(match_operand:P 0 "register_operand")
+   (match_operand:P 1 "vector_length_operand")
+   (match_operand:P 2 "")]
+  "TARGET_VECTOR"
+{
+  poly_int64 nunits = rtx_to_poly_int64 (operands[2]);
+  /* We arbitrary picked QImode as inner scalar mode to get vector mode.
+     since vsetvl only demand ratio. We let VSETVL PASS to optimize it.  */
+  scalar_int_mode mode = QImode;
+  machine_mode rvv_mode = riscv_vector::get_vector_mode (mode, nunits).require ();
+  emit_insn (riscv_vector::gen_no_side_effects_vsetvl_rtx (rvv_mode, operands[0], operands[1]));
+  DONE;
+})
+
 ;; =========================================================================
 ;; == Loads/Stores
 ;; =========================================================================
diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
index 00e1b20c6c6..d770e5e826e 100644
--- a/gcc/config/riscv/riscv-protos.h
+++ b/gcc/config/riscv/riscv-protos.h
@@ -232,6 +232,7 @@ enum vlen_enum
   RVV_64 = 64,
   RVV_65536 = 65536
 };
+rtx gen_no_side_effects_vsetvl_rtx (machine_mode, rtx, rtx);
 bool slide1_sew64_helper (int, machine_mode, machine_mode,
 			  machine_mode, rtx *);
 rtx gen_avl_for_scalar_move (rtx);
diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index 49752cd8899..83277fc2c05 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -1280,7 +1280,7 @@ force_vector_length_operand (rtx vl)
   return vl;
 }
 
-static rtx
+rtx
 gen_no_side_effects_vsetvl_rtx (machine_mode vmode, rtx vl, rtx avl)
 {
   unsigned int sew = get_sew (vmode);
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
new file mode 100644
index 00000000000..b8e0ca0f1f8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/partial/select_vl-1.c
@@ -0,0 +1,28 @@
+/* { 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" } */
+
+#include <stdint-gcc.h>
+
+#define TEST_TYPE(TYPE)                                                        \
+  __attribute__ ((noipa)) void select_vl_##TYPE (TYPE *__restrict dst,         \
+						 TYPE *__restrict a, int n)    \
+  {                                                                            \
+    for (int i = 0; i < n; i++)                                                \
+      dst[i] = a[i];                                                           \
+  }
+
+#define TEST_ALL()                                                             \
+  TEST_TYPE (int8_t)                                                           \
+  TEST_TYPE (uint8_t)                                                          \
+  TEST_TYPE (int16_t)                                                          \
+  TEST_TYPE (uint16_t)                                                         \
+  TEST_TYPE (int32_t)                                                          \
+  TEST_TYPE (uint32_t)                                                         \
+  TEST_TYPE (int64_t)                                                          \
+  TEST_TYPE (uint64_t)                                                         \
+  TEST_TYPE (float)                                                            \
+  TEST_TYPE (double)
+
+TEST_ALL ()
+
+/* { dg-final { scan-tree-dump-times "\.SELECT_VL" 10 "optimized" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-2.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-2.c
index 89eeaf6315f..e52e07ddd09 100644
--- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-2.c
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-2.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-additional-options "-march=rv32gcv -mabi=ilp32d --param=riscv-autovec-preference=scalable" } */
+/* { dg-additional-options "-march=rv32gcv -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-schedule-insns" } */
 
 #include <stdint-gcc.h>
 
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-5.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-5.c
index a9a7198feb4..49c85efbf3a 100644
--- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-5.c
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/ternop/ternop-5.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-additional-options "-march=rv32gcv -mabi=ilp32d --param=riscv-autovec-preference=scalable" } */
+/* { dg-additional-options "-march=rv32gcv -mabi=ilp32d --param=riscv-autovec-preference=scalable -fno-schedule-insns" } */
 
 #include <stdint-gcc.h>
 
-- 
2.36.1