riscv: bitmanip: add orc.b as an unspec

As a basis for optimized string functions (e.g., the by-pieces
implementations), we need orc.b available.  This adds orc.b as an
unspec, so we can expand to it.

gcc/ChangeLog:

	* config/riscv/bitmanip.md (orcb<mode>2): Add orc.b as an
	  unspec.
	* config/riscv/riscv.md: Add UNSPEC_ORC_B.

Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>

diff --git a/gcc/config/riscv/bitmanip.md b/gcc/config/riscv/bitmanip.md
index d26f356..48c249f 100644 (file)
--- a/gcc/config/riscv/bitmanip.md
+++ b/gcc/config/riscv/bitmanip.md
@@ -255,6 +255,14 @@
   "rolw\t%0,%1,%2"
   [(set_attr "type" "bitmanip")])
 
+;; orc.b (or-combine) is added as an unspec for the benefit of the support
+;; for optimized string functions (such as strcmp).
+(define_insn "orcb<mode>2"
+  [(set (match_operand:X 0 "register_operand" "=r")
+       (unspec:X [(match_operand:X 1 "register_operand" "r")] UNSPEC_ORC_B))]
+  "TARGET_ZBB"
+  "orc.b\t%0,%1")
+
 (define_insn "bswap<mode>2"
   [(set (match_operand:X 0 "register_operand" "=r")
         (bswap:X (match_operand:X 1 "register_operand" "r")))]

diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 798f737..532289d 100644 (file)
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -62,6 +62,9 @@
 
   ;; Stack tie
   UNSPEC_TIE
+
+  ;; OR-COMBINE
+  UNSPEC_ORC_B
 ])
 
 (define_c_enum "unspecv" [