[PATCH v2] RISC-V: Split off shift patterns for autovectorization.

[Robin Dapp <rdapp.gcc@gmail.com>]

> "csr_operand" does seem wrong, though, as that just accepts constants.
> Maybe "arith_operand" is the way to go?  I haven't looked at the
> V immediates though.

I was pondering changing the shift-count operand to QImode everywhere
but that indeed does not help code generation across the board.  It can
still work but might require extra patterns here and there.

"csr_operand" accepts 0-31 constants as well as registers which should
be fine here.

No changes from v1 apart from the RISC-V in the subject and a bit of
rebasing and comments.


This patch splits off the shift patterns of the binop patterns.
This is necessary as the scalar shifts require a Pmode operand
as shift count.  To this end, a new iterator any_int_binop_no_shift
is introduced.  At a later point when the binops are split up
further in commutative and non-commutative patterns (which both
do not include the shift patterns) we might not need this anymore.

gcc/ChangeLog:

	* config/riscv/autovec.md (<optab><mode>3): Add scalar shift
	pattern.
	(v<optab><mode>3): Add vector shift pattern.
	* config/riscv/vector-iterators.md: New iterator.
---
 gcc/config/riscv/autovec.md          | 47 +++++++++++++++++++++++++++-
 gcc/config/riscv/vector-iterators.md |  4 +++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/gcc/config/riscv/autovec.md b/gcc/config/riscv/autovec.md
index 58926ed3e67..ac0c939d277 100644
--- a/gcc/config/riscv/autovec.md
+++ b/gcc/config/riscv/autovec.md
@@ -97,7 +97,7 @@ (define_expand "@vec_series<mode>"
 
 (define_expand "<optab><mode>3"
   [(set (match_operand:VI 0 "register_operand")
-    (any_int_binop:VI
+    (any_int_binop_no_shift:VI
      (match_operand:VI 1 "<binop_rhs1_predicate>")
      (match_operand:VI 2 "<binop_rhs2_predicate>")))]
   "TARGET_VECTOR"
@@ -119,3 +119,48 @@ (define_expand "<optab><mode>3"
 				  NULL, <VM>mode);
   DONE;
 })
+
+;; -------------------------------------------------------------------------
+;; ---- [INT] Binary shifts by scalar.
+;; -------------------------------------------------------------------------
+;; Includes:
+;; - vsll.vx/vsra.vx/vsrl.vx
+;; - vsll.vi/vsra.vi/vsrl.vi
+;; -------------------------------------------------------------------------
+
+(define_expand "<optab><mode>3"
+  [(set (match_operand:VI 0 "register_operand")
+    (any_shift:VI
+     (match_operand:VI 1 "register_operand")
+     (match_operand:<VEL> 2 "csr_operand")))]
+  "TARGET_VECTOR"
+{
+  if (!CONST_SCALAR_INT_P (operands[2]))
+      operands[2] = gen_lowpart (Pmode, operands[2]);
+  riscv_vector::emit_len_binop (code_for_pred_scalar
+				(<CODE>, <MODE>mode),
+				operands[0], operands[1], operands[2],
+				NULL_RTX, <VM>mode, Pmode);
+  DONE;
+})
+
+;; -------------------------------------------------------------------------
+;; ---- [INT] Binary shifts by scalar.
+;; -------------------------------------------------------------------------
+;; Includes:
+;; - vsll.vv/vsra.vv/vsrl.vv
+;; -------------------------------------------------------------------------
+
+(define_expand "v<optab><mode>3"
+  [(set (match_operand:VI 0 "register_operand")
+    (any_shift:VI
+     (match_operand:VI 1 "register_operand")
+     (match_operand:VI 2 "vector_shift_operand")))]
+  "TARGET_VECTOR"
+{
+  riscv_vector::emit_len_binop (code_for_pred
+				(<CODE>, <MODE>mode),
+				operands[0], operands[1], operands[2],
+				NULL_RTX, <VM>mode);
+  DONE;
+})
diff --git a/gcc/config/riscv/vector-iterators.md b/gcc/config/riscv/vector-iterators.md
index 29c9d77674b..5cf958ba845 100644
--- a/gcc/config/riscv/vector-iterators.md
+++ b/gcc/config/riscv/vector-iterators.md
@@ -1409,6 +1409,10 @@ (define_code_iterator any_commutative_binop [plus and ior xor
 
 (define_code_iterator any_non_commutative_binop [minus div udiv mod umod])
 
+(define_code_iterator any_int_binop_no_shift
+ [plus minus and ior xor smax umax smin umin mult div udiv mod umod
+])
+
 (define_code_iterator any_sat_int_binop [ss_plus ss_minus us_plus us_minus])
 (define_code_iterator sat_int_plus_binop [ss_plus us_plus])
 (define_code_iterator sat_int_minus_binop [ss_minus us_minus])
-- 
2.40.0