This part LGTM.
juzhe.zh...@rivai.ai
From: Robin Dapp
Date: 2023-05-10 23:24
To: gcc-patches; juzhe.zh...@rivai.ai; Kito Cheng; Michael Collison; palmer;
jeffreyalaw
CC: rdapp.gcc
Subject: [PATCH] riscv: Clarify vlmax and length handling.
Hi,
this patch tries to improve the wrappers that emit either vlmax or
non-vlmax operations. Now, emit_len_op can be used to
emit a regular operation. Depending on whether a length != NULL
is passed either no VLMAX flags are set or we emit a vsetvli and
set VLMAX flags. The patch also adds some comments that describes
some of the rationale of the current handling of vlmax/nonvlmax
operations.
Bootstrapped and regtested.
Regards
Robin
--
gcc/ChangeLog:
* config/riscv/autovec.md: Use renamed functions.
* config/riscv/riscv-protos.h (emit_vlmax_op): Rename.
(emit_vlmax_reg_op): To this.
(emit_nonvlmax_op): Rename.
(emit_len_op): To this.
(emit_nonvlmax_binop): Rename.
(emit_len_binop): To this.
* config/riscv/riscv-v.cc (emit_pred_op): Add default parameter.
(emit_pred_binop): Remove vlmax_p.
(emit_vlmax_op): Rename.
(emit_vlmax_reg_op): To this.
(emit_nonvlmax_op): Rename.
(emit_len_op): To this.
(emit_nonvlmax_binop): Rename.
(emit_len_binop): To this.
(sew64_scalar_helper): Use renamed functions.
(expand_tuple_move): Use renamed functions.
* config/riscv/riscv.cc (vector_zero_call_used_regs): Use
renamed functions.
* config/riscv/vector.md: Use renamed functions.
---
gcc/config/riscv/autovec.md | 24 +++++-----
gcc/config/riscv/riscv-protos.h | 8 ++--
gcc/config/riscv/riscv-v.cc | 82 ++++++++++++++++++++-------------
gcc/config/riscv/riscv.cc | 4 +-
gcc/config/riscv/vector.md | 12 +++--
5 files changed, 75 insertions(+), 55 deletions(-)
diff --git a/gcc/config/riscv/autovec.md b/gcc/config/riscv/autovec.md
index 15f8d007e07..8347e42bb9c 100644
--- a/gcc/config/riscv/autovec.md
+++ b/gcc/config/riscv/autovec.md
@@ -31,8 +31,8 @@ (define_expand "len_load_<mode>"
(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);
+ riscv_vector::emit_len_op (code_for_pred_mov (<MODE>mode), operands[0],
+ operands[1], operands[2], <VM>mode);
DONE;
})
@@ -43,8 +43,8 @@ (define_expand "len_store_<mode>"
(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);
+ riscv_vector::emit_len_op (code_for_pred_mov (<MODE>mode), operands[0],
+ operands[1], operands[2], <VM>mode);
DONE;
})
@@ -79,15 +79,15 @@ (define_expand "<optab><mode>3"
if (inner == E_QImode || inner == E_HImode || inner == E_SImode)
op2mode = inner;
- riscv_vector::emit_nonvlmax_binop (code_for_pred_scalar
- (<BINOP_TO_UPPERCASE>, <MODE>mode),
- operands[0], operands[1], cst,
- NULL_RTX, <VM>mode, op2mode);
+ riscv_vector::emit_len_binop (code_for_pred_scalar
+ (<BINOP_TO_UPPERCASE>, <MODE>mode),
+ operands[0], operands[1], cst,
+ NULL_RTX, <VM>mode, op2mode);
}
else
- riscv_vector::emit_nonvlmax_binop (code_for_pred
- (<BINOP_TO_UPPERCASE>, <MODE>mode),
- operands[0], operands[1], operands[2],
- NULL_RTX, <VM>mode);
+ riscv_vector::emit_len_binop (code_for_pred
+ (<BINOP_TO_UPPERCASE>, <MODE>mode),
+ operands[0], operands[1], operands[2],
+ NULL_RTX, <VM>mode);
DONE;
})
diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
index 75cdb90b9c9..bfdf09b17ee 100644
--- a/gcc/config/riscv/riscv-protos.h
+++ b/gcc/config/riscv/riscv-protos.h
@@ -167,10 +167,10 @@ bool legitimize_move (rtx, rtx, machine_mode);
void emit_vlmax_vsetvl (machine_mode, rtx);
void emit_hard_vlmax_vsetvl (machine_mode, rtx);
void emit_vlmax_op (unsigned, rtx, rtx, machine_mode);
-void emit_vlmax_op (unsigned, rtx, rtx, rtx, machine_mode);
-void emit_nonvlmax_op (unsigned, rtx, rtx, rtx, machine_mode);
-void emit_nonvlmax_binop (unsigned, rtx, rtx, rtx, rtx, machine_mode,
- machine_mode = VOIDmode);
+void emit_vlmax_reg_op (unsigned, rtx, rtx, rtx, machine_mode);
+void emit_len_op (unsigned, rtx, rtx, rtx, machine_mode);
+void emit_len_binop (unsigned, rtx, rtx, rtx, rtx, machine_mode, machine_mode =
+ VOIDmode);
enum vlmul_type get_vlmul (machine_mode);
unsigned int get_ratio (machine_mode);
unsigned int get_nf (machine_mode);
diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index 3c43dfc5eea..07b7783282f 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -99,27 +99,24 @@ public:
add_vundef_operand (dest_mode);
}
- void set_len_and_policy (rtx len, bool vlmax_p)
+ void set_len_and_policy (rtx len, bool force_vlmax = false)
{
+ bool vlmax_p = force_vlmax;
gcc_assert (has_dest);
- gcc_assert (len || vlmax_p);
- if (len)
- add_input_operand (len, Pmode);
- else
+ if (!len)
{
- rtx vlmax = gen_reg_rtx (Pmode);
- emit_vlmax_vsetvl (dest_mode, vlmax);
- add_input_operand (vlmax, Pmode);
+ vlmax_p = true;
+ len = gen_reg_rtx (Pmode);
+ emit_vlmax_vsetvl (dest_mode, len);
}
+ add_input_operand (len, Pmode);
+
if (GET_MODE_CLASS (dest_mode) != MODE_VECTOR_BOOL)
add_policy_operand (get_prefer_tail_policy (), get_prefer_mask_policy ());
- if (vlmax_p)
- add_avl_type_operand (avl_type::VLMAX);
- else
- add_avl_type_operand (avl_type::NONVLMAX);
+ add_avl_type_operand (vlmax_p ? avl_type::VLMAX : avl_type::NONVLMAX);
}
void expand (enum insn_code icode, bool temporary_volatile_p = false)
@@ -251,14 +248,14 @@ set_expander_dest_and_mask (insn_expander<MAX_OPERANDS>
&e, rtx mask, rtx dest,
/* Emit an RVV unmask && vl mov from SRC to DEST. */
static void
emit_pred_op (unsigned icode, rtx mask, rtx dest, rtx src, rtx len,
- machine_mode mask_mode, bool vlmax_p)
+ machine_mode mask_mode, bool force_vlmax = false)
{
insn_expander<8> e;
e.set_dest_and_mask (mask, dest, mask_mode);
e.add_input_operand (src, GET_MODE (src));
- e.set_len_and_policy (len, vlmax_p);
+ e.set_len_and_policy (len, force_vlmax);
e.expand ((enum insn_code) icode, MEM_P (dest) || MEM_P (src));
}
@@ -266,8 +263,7 @@ emit_pred_op (unsigned icode, rtx mask, rtx dest, rtx src,
rtx len,
/* Emit an RVV unmask && vl mov from SRC to DEST. */
static void
emit_pred_binop (unsigned icode, rtx mask, rtx dest, rtx src1, rtx src2,
- rtx len, machine_mode mask_mode, machine_mode op2mode,
- bool vlmax_p)
+ rtx len, machine_mode mask_mode, machine_mode op2mode)
{
insn_expander<9> e;
e.set_dest_and_mask (mask, dest, mask_mode);
@@ -275,37 +271,59 @@ emit_pred_binop (unsigned icode, rtx mask, rtx dest, rtx
src1, rtx src2,
e.add_input_operand (src1, GET_MODE (src1));
e.add_input_operand (src2, op2mode == VOIDmode ? GET_MODE (src2) : op2mode);
- e.set_len_and_policy (len, vlmax_p);
+ e.set_len_and_policy (len);
e.expand ((enum insn_code) icode, MEM_P (dest) || MEM_P (src1) || MEM_P
(src2));
}
+/* The RISC-V vsetvli pass uses vlmax operation for optimization. Whether or
+ not an instruction actually is a vlmax operation is not recognizable from
+ the length operand alone but the avl_type operand is used instead.
+ In general, there are two cases:
+
+ - Emit a vlmax operation by passing a NULL length. Here we emit
+ a vsetvli with vlmax configuration and set the avl_type to VLMAX.
+ - Emit an operation that uses the existing (last-set) length and
+ set the avl_type to NONVLMAX.
+
+ Sometimes we also need to set the VLMAX avl_type to an operation that
+ already uses a given length register. This can happen during or after
+ register allocation when we are not allowed to create a new register.
+ For that case we also allow to set the avl_type to VLMAX.
+*/
+
+/* This function emits a VLMAX vsetvli followed by the actual operation. */
void
emit_vlmax_op (unsigned icode, rtx dest, rtx src, machine_mode mask_mode)
{
- emit_pred_op (icode, NULL_RTX, dest, src, NULL_RTX, mask_mode, true);
+ emit_pred_op (icode, NULL_RTX, dest, src, NULL_RTX, mask_mode);
}
+/* This function emits an operation with a given LEN that is determined
+ by a previously emitted VLMAX vsetvli. */
void
-emit_vlmax_op (unsigned icode, rtx dest, rtx src, rtx len,
- machine_mode mask_mode)
+emit_len_op (unsigned icode, rtx dest, rtx src, rtx len,
+ machine_mode mask_mode)
{
- emit_pred_op (icode, NULL_RTX, dest, src, len, mask_mode, true);
+ emit_pred_op (icode, NULL_RTX, dest, src, len, mask_mode);
}
+/* This function emits an operation with a given LEN that is known to be
+ a preceding VLMAX. It also sets the VLMAX flag which allows further
+ optimization in the vsetvli pass. */
void
-emit_nonvlmax_op (unsigned icode, rtx dest, rtx src, rtx len,
- machine_mode mask_mode)
+emit_vlmax_reg_op (unsigned icode, rtx dest, rtx src, rtx len,
+ machine_mode mask_mode)
{
- emit_pred_op (icode, NULL_RTX, dest, src, len, mask_mode, false);
+ emit_pred_op (icode, NULL_RTX, dest, src, len, mask_mode,
+ /* Force VLMAX */ true);
}
void
-emit_nonvlmax_binop (unsigned icode, rtx dest, rtx src1, rtx src2, rtx len,
- machine_mode mask_mode, machine_mode op2mode)
+emit_len_binop (unsigned icode, rtx dest, rtx src1, rtx src2, rtx len,
+ machine_mode mask_mode, machine_mode op2mode)
{
- emit_pred_binop (icode, NULL_RTX, dest, src1, src2, len, mask_mode, op2mode,
- false);
+ emit_pred_binop (icode, NULL_RTX, dest, src1, src2, len, mask_mode, op2mode);
}
static void
@@ -667,8 +685,8 @@ sew64_scalar_helper (rtx *operands, rtx *scalar_op, rtx vl,
*scalar_op = force_reg (scalar_mode, *scalar_op);
rtx tmp = gen_reg_rtx (vector_mode);
- riscv_vector::emit_nonvlmax_op (code_for_pred_broadcast (vector_mode), tmp,
- *scalar_op, vl, mask_mode);
+ riscv_vector::emit_len_op (code_for_pred_broadcast (vector_mode), tmp,
+ *scalar_op, vl, mask_mode);
emit_vector_func (operands, tmp);
return true;
@@ -974,7 +992,7 @@ expand_tuple_move (machine_mode mask_mode, rtx *ops)
rtx mem = gen_rtx_MEM (subpart_mode, ops[3]);
if (fractional_p)
- emit_vlmax_op (code_for_pred_mov (subpart_mode), subreg, mem,
+ emit_vlmax_reg_op (code_for_pred_mov (subpart_mode), subreg, mem,
ops[4], mask_mode);
else
emit_move_insn (subreg, mem);
@@ -996,7 +1014,7 @@ expand_tuple_move (machine_mode mask_mode, rtx *ops)
rtx mem = gen_rtx_MEM (subpart_mode, ops[3]);
if (fractional_p)
- emit_vlmax_op (code_for_pred_mov (subpart_mode), mem, subreg,
+ emit_vlmax_reg_op (code_for_pred_mov (subpart_mode), mem, subreg,
ops[4], mask_mode);
else
emit_move_insn (mem, subreg);
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 9e08a1bfe35..9a493295a38 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -7373,8 +7373,8 @@ vector_zero_call_used_regs (HARD_REG_SET
need_zeroed_hardregs)
emitted_vlmax_vsetvl = true;
}
- riscv_vector::emit_vlmax_op (code_for_pred_mov (mode), target,
- CONST0_RTX (mode), vl, mask_mode);
+ riscv_vector::emit_vlmax_reg_op (code_for_pred_mov (mode), target,
+ CONST0_RTX (mode), vl, mask_mode);
SET_HARD_REG_BIT (zeroed_hardregs, regno);
}
diff --git a/gcc/config/riscv/vector.md b/gcc/config/riscv/vector.md
index 9ccc0d6a513..75479f27bcd 100644
--- a/gcc/config/riscv/vector.md
+++ b/gcc/config/riscv/vector.md
@@ -721,8 +721,9 @@ (define_insn_and_split "*mov<V_FRACT:mode><P:mode>_lra"
else
{
riscv_vector::emit_vlmax_vsetvl (<V_FRACT:MODE>mode, operands[2]);
- riscv_vector::emit_vlmax_op (code_for_pred_mov (<V_FRACT:MODE>mode),
- operands[0], operands[1], operands[2], <VM>mode);
+ riscv_vector::emit_vlmax_reg_op (code_for_pred_mov (<V_FRACT:MODE>mode),
+ operands[0], operands[1], operands[2],
+ <VM>mode);
}
DONE;
})
@@ -741,8 +742,9 @@ (define_insn_and_split "*mov<VB:mode><P:mode>_lra"
else
{
riscv_vector::emit_vlmax_vsetvl (<VB:MODE>mode, operands[2]);
- riscv_vector::emit_vlmax_op (code_for_pred_mov (<VB:MODE>mode),
- operands[0], operands[1], operands[2], <VB:MODE>mode);
+ riscv_vector::emit_vlmax_reg_op (code_for_pred_mov (<VB:MODE>mode),
+ operands[0], operands[1], operands[2],
+ <VB:MODE>mode);
}
DONE;
})
@@ -806,7 +808,7 @@ (define_expand "vec_duplicate<mode>"
"TARGET_VECTOR"
{
riscv_vector::emit_vlmax_op (code_for_pred_broadcast (<MODE>mode),
- operands[0], operands[1], <VM>mode);
+ operands[0], operands[1], <VM>mode);
DONE;
}
)
--
2.40.0
