[2/3] RISC-V: Enable basic auto-vectorization for RVV
Commit Message
From: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>
This patch enables auto-vectorization accurately according to '-march'
And add len_load/len_store pattern.
For example, for -march=rv32gc_zve32x, we should allow SEW = 64 RVV
auto-vectorization.
gcc/ChangeLog:
* config/riscv/riscv-protos.h (preferred_simd_mode): Enable basic auto-vectorization support.
* config/riscv/riscv-v.cc (autovec_use_vlmax_p): New function.
(preferred_simd_mode): Ditto.
* config/riscv/riscv.cc (riscv_convert_vector_bits): Enable basic auto-vectorization support.
(riscv_preferred_simd_mode): New function.
(TARGET_VECTORIZE_PREFERRED_SIMD_MODE): New target hook.
* config/riscv/vector.md: include autovec.md
* config/riscv/autovec.md: New file.
---
gcc/config/riscv/autovec.md | 49 ++++++++++++++++++++++++++++++
gcc/config/riscv/riscv-protos.h | 1 +
gcc/config/riscv/riscv-v.cc | 53 +++++++++++++++++++++++++++++++++
gcc/config/riscv/riscv.cc | 24 ++++++++++++++-
gcc/config/riscv/vector.md | 4 ++-
5 files changed, 129 insertions(+), 2 deletions(-)
create mode 100644 gcc/config/riscv/autovec.md
new file mode 100644
@@ -0,0 +1,49 @@
+;; Machine description for auto-vectorization using RVV for GNU compiler.
+;; Copyright (C) 2023 Free Software Foundation, Inc.
+;; Contributed by Juzhe Zhong (juzhe.zhong@rivai.ai), RiVAI Technologies Ltd.
+
+;; This file is part of GCC.
+
+;; GCC is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; GCC is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GCC; see the file COPYING3. If not see
+;; <http://www.gnu.org/licenses/>.
+
+;; =========================================================================
+;; == Loads/Stores
+;; =========================================================================
+
+;; len_load/len_store is a sub-optimal pattern for RVV auto-vectorization support.
+;; We will replace them when len_maskload/len_maskstore is supported in loop vectorizer.
+(define_expand "len_load_<mode>"
+ [(match_operand:V 0 "register_operand")
+ (match_operand:V 1 "memory_operand")
+ (match_operand 2 "vector_length_operand")
+ (match_operand 3 "const_0_operand")]
+ "TARGET_VECTOR"
+{
+ riscv_vector::emit_nonvlmax_op (code_for_pred_mov (<MODE>mode), operands[0],
+ operands[1], operands[2], <VM>mode);
+ DONE;
+})
+
+(define_expand "len_store_<mode>"
+ [(match_operand:V 0 "memory_operand")
+ (match_operand:V 1 "register_operand")
+ (match_operand 2 "vector_length_operand")
+ (match_operand 3 "const_0_operand")]
+ "TARGET_VECTOR"
+{
+ riscv_vector::emit_nonvlmax_op (code_for_pred_mov (<MODE>mode), operands[0],
+ operands[1], operands[2], <VM>mode);
+ DONE;
+})
@@ -207,6 +207,7 @@ enum vlen_enum
bool slide1_sew64_helper (int, machine_mode, machine_mode,
machine_mode, rtx *);
rtx gen_avl_for_scalar_move (rtx);
+machine_mode preferred_simd_mode (scalar_mode);
}
/* We classify builtin types into two classes:
@@ -43,6 +43,7 @@
#include "optabs.h"
#include "tm-constrs.h"
#include "rtx-vector-builder.h"
+#include "targhooks.h"
using namespace riscv_vector;
@@ -742,4 +743,56 @@ gen_avl_for_scalar_move (rtx avl)
}
}
+/* SCALABLE means that the vector-length is agnostic (run-time invariant and
+ compile-time unknown). FIXED meands that the vector-length is specific
+ (compile-time known). Both RVV_SCALABLE and RVV_FIXED_VLMAX are doing
+ auto-vectorization using VLMAX vsetvl configuration. */
+static bool
+autovec_use_vlmax_p (void)
+{
+ return riscv_autovec_preference == RVV_SCALABLE
+ || riscv_autovec_preference == RVV_FIXED_VLMAX;
+}
+
+/* Return the vectorization machine mode for RVV according to LMUL. */
+machine_mode
+preferred_simd_mode (scalar_mode mode)
+{
+ /* We only enable auto-vectorization when TARGET_MIN_VLEN >= 128
+ which is -march=rv64gcv. Since GCC loop vectorizer report ICE
+ when we enable -march=rv64gc_zve32* and -march=rv32gc_zve64*.
+ in the 'can_duplicate_and_interleave_p' of tree-vect-slp.cc. Since we have
+ VNx1SImode in -march=*zve32* and VNx1DImode in -march=*zve64*, they are
+ enabled in targetm. vector_mode_supported_p and SLP vectorizer will try to
+ use them. Currently, we can support auto-vectorization in
+ -march=rv32_zve32x_zvl128b. Wheras, -march=rv32_zve32x_zvl32b or
+ -march=rv32_zve32x_zvl64b are disabled.
+ */
+ if (autovec_use_vlmax_p ())
+ {
+ /* If TARGET_MIN_VLEN < 128, we don't allow LMUL < 2
+ auto-vectorization since Loop Vectorizer may use VNx1SImode or
+ VNx1DImode to vectorize which will create ICE in the
+ 'can_duplicate_and_interleave_p' of tree-vect-slp.cc. */
+ if (TARGET_MIN_VLEN < 128 && riscv_autovec_lmul < RVV_M2)
+ return word_mode;
+ /* We use LMUL = 1 as base bytesize which is BYTES_PER_RISCV_VECTOR and
+ riscv_autovec_lmul as multiply factor to calculate the the NUNITS to
+ get the auto-vectorization mode. */
+ poly_uint64 nunits;
+ poly_uint64 vector_size
+ = BYTES_PER_RISCV_VECTOR * ((int) riscv_autovec_lmul);
+ poly_uint64 scalar_size = GET_MODE_SIZE (mode);
+ if (!multiple_p (vector_size, scalar_size, &nunits))
+ return word_mode;
+ machine_mode rvv_mode;
+ if (get_vector_mode (mode, nunits).exists (&rvv_mode))
+ return rvv_mode;
+ }
+ /* TODO: We will support minimum length VLS auto-vectorization in the future.
+ */
+ return word_mode;
+}
+
+
} // namespace riscv_vector
@@ -6228,7 +6228,15 @@ riscv_convert_vector_bits (void)
to set RVV mode size. The RVV machine modes size are run-time constant if
TARGET_VECTOR is enabled. The RVV machine modes size remains default
compile-time constant if TARGET_VECTOR is disabled. */
- return TARGET_VECTOR ? poly_uint16 (1, 1) : 1;
+ if (TARGET_VECTOR)
+ {
+ if (riscv_autovec_preference == RVV_FIXED_VLMAX)
+ return (int) TARGET_MIN_VLEN / (riscv_bytes_per_vector_chunk * 8);
+ else
+ return poly_uint16 (1, 1);
+ }
+ else
+ return 1;
}
/* Implement TARGET_OPTION_OVERRIDE. */
@@ -7158,6 +7166,17 @@ riscv_zero_call_used_regs (HARD_REG_SET need_zeroed_hardregs)
& ~zeroed_hardregs);
}
+/* Implement TARGET_VECTORIZE_PREFERRED_SIMD_MODE. */
+
+static machine_mode
+riscv_preferred_simd_mode (scalar_mode mode)
+{
+ if (TARGET_VECTOR)
+ return riscv_vector::preferred_simd_mode (mode);
+
+ return word_mode;
+}
+
/* Initialize the GCC target structure. */
#undef TARGET_ASM_ALIGNED_HI_OP
#define TARGET_ASM_ALIGNED_HI_OP "\t.half\t"
@@ -7412,6 +7431,9 @@ riscv_zero_call_used_regs (HARD_REG_SET need_zeroed_hardregs)
#undef TARGET_ZERO_CALL_USED_REGS
#define TARGET_ZERO_CALL_USED_REGS riscv_zero_call_used_regs
+#undef TARGET_VECTORIZE_PREFERRED_SIMD_MODE
+#define TARGET_VECTORIZE_PREFERRED_SIMD_MODE riscv_preferred_simd_mode
+
struct gcc_target targetm = TARGET_INITIALIZER;
#include "gt-riscv.h"
@@ -23,7 +23,7 @@
;; This file include :
;;
;; - Intrinsics (https://github.com/riscv/rvv-intrinsic-doc)
-;; - Auto-vectorization (TBD)
+;; - Auto-vectorization (autovec.md)
;; - Combine optimization (TBD)
(include "vector-iterators.md")
@@ -7419,3 +7419,5 @@
"vle<sew>ff.v\t%0,%3%p1"
[(set_attr "type" "vldff")
(set_attr "mode" "<MODE>")])
+
+(include "autovec.md")