[gcc r13-1122] xtensa: Add some dedicated patterns that correspond to GIMPLE canonicalizations

[gcc r13-1122] xtensa: Add some dedicated patterns that correspond to GIMPLE canonicalizations

[Max Filippov]

https://gcc.gnu.org/g:c95e307e3a978166cd5d6817ec9d8293825ff3fb

commit r13-1122-gc95e307e3a978166cd5d6817ec9d8293825ff3fb
Author: Takayuki 'January June' Suwa <jjsuwa_sys3175@yahoo.co.jp>
Date:   Tue Jun 14 12:37:54 2022 +0900

    xtensa: Add some dedicated patterns that correspond to GIMPLE canonicalizations
    
    This patch offers better RTL representations against straightforward
    derivations from some tree optimizers' canonicalized forms.
    
    - rounding up to even, such as '(x + (x & 1))', is canonicalized to
      '((x + 1) & -2)', but the former is one instruction less than the latter
      in Xtensa ISA.
    - signed greater or equal to zero as logical value '((signed)x >= 0)',
      is canonicalized to '((unsigned)(x ^ -1) >> 31)', but the equivalent
      '(((signed)x >> 31) + 1)' is one instruction less.
    
    gcc/ChangeLog:
    
            * config/xtensa/xtensa.md (*round_up_to_even):
            New insn-and-split pattern.
            (*signed_ge_zero): Ditto.

Diff:
---
 gcc/config/xtensa/xtensa.md | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index 3b05166988f..fa2a4a05a25 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -2704,3 +2704,48 @@
   xtensa_expand_atomic (<CODE>, operands[0], operands[1], operands[2], true);
   DONE;
 })
+
+(define_insn_and_split "*round_up_to_even"
+  [(set (match_operand:SI 0 "register_operand" "=a")
+	(and:SI (plus:SI (match_operand:SI 1 "register_operand" "r")
+			 (const_int 1))
+		(const_int -2)))]
+  ""
+  "#"
+  "can_create_pseudo_p ()"
+  [(set (match_dup 2)
+	(and:SI (match_dup 1)
+		(const_int 1)))
+   (set (match_dup 0)
+	(plus:SI (match_dup 2)
+		 (match_dup 1)))]
+{
+  operands[2] = gen_reg_rtx (SImode);
+}
+  [(set_attr "type"	"arith")
+   (set_attr "mode"	"SI")
+   (set (attr "length")
+	(if_then_else (match_test "TARGET_DENSITY")
+		      (const_int 5)
+		      (const_int 6)))])
+
+(define_insn_and_split "*signed_ge_zero"
+  [(set (match_operand:SI 0 "register_operand" "=a")
+	(ge:SI (match_operand:SI 1 "register_operand" "r")
+	       (const_int 0)))]
+  ""
+  "#"
+  ""
+  [(set (match_dup 0)
+	(ashiftrt:SI (match_dup 1)
+		     (const_int 31)))
+   (set (match_dup 0)
+	(plus:SI (match_dup 0)
+		 (const_int 1)))]
+  ""
+  [(set_attr "type"	"arith")
+   (set_attr "mode"	"SI")
+   (set (attr "length")
+	(if_then_else (match_test "TARGET_DENSITY")
+		      (const_int 5)
+		      (const_int 6)))])