[v2] RISC-V: Add bext pattern for ZBS

Message ID 20230508141122.127023-1-rzinsly@ventanamicro.com
State Accepted
Headers
Series [v2] RISC-V: Add bext pattern for ZBS |

Checks

Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Raphael Moreira Zinsly May 8, 2023, 2:11 p.m. UTC
  Changes since v1: 
        - Removed name clash change.
        - Fix new pattern indentation.

-- >8 --

When (a & (1 << bit_no)) is tested inside an IF we can use a bit extract.

	gcc/ChangeLog:

		* config/riscv/bitmanip.md
		(branch<X:mode>_bext): New split pattern.

	gcc/testsuite/ChangeLog:
		* gcc.target/riscv/zbs-bext-02.c: New test.
---
 gcc/config/riscv/bitmanip.md                 | 23 ++++++++++++++++++++
 gcc/testsuite/gcc.target/riscv/zbs-bext-02.c | 18 +++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/riscv/zbs-bext-02.c
  

Comments

Jeff Law May 8, 2023, 9:59 p.m. UTC | #1
On 5/8/23 08:11, Raphael Moreira Zinsly wrote:
> Changes since v1:
>          - Removed name clash change.
>          - Fix new pattern indentation.
> 
> -- >8 --
> 
> When (a & (1 << bit_no)) is tested inside an IF we can use a bit extract.
> 
> 	gcc/ChangeLog:
> 
> 		* config/riscv/bitmanip.md
> 		(branch<X:mode>_bext): New split pattern.
> 
> 	gcc/testsuite/ChangeLog:
> 		* gcc.target/riscv/zbs-bext-02.c: New test.
OK
jeff
  
Jeff Law May 20, 2023, 3:42 a.m. UTC | #2
On 5/8/23 08:11, Raphael Moreira Zinsly wrote:
> Changes since v1:
>          - Removed name clash change.
>          - Fix new pattern indentation.
> 
> -- >8 --
> 
> When (a & (1 << bit_no)) is tested inside an IF we can use a bit extract.
> 
> 	gcc/ChangeLog:
> 
> 		* config/riscv/bitmanip.md
> 		(branch<X:mode>_bext): New split pattern.
> 
> 	gcc/testsuite/ChangeLog:
> 		* gcc.target/riscv/zbs-bext-02.c: New test.
I went ahead and pushed this.

jeff
  

Patch

diff --git a/gcc/config/riscv/bitmanip.md b/gcc/config/riscv/bitmanip.md
index a27fc3e34a1..df522073344 100644
--- a/gcc/config/riscv/bitmanip.md
+++ b/gcc/config/riscv/bitmanip.md
@@ -720,6 +720,29 @@ 
    operands[9] = GEN_INT (clearbit);
 })
 
+;; IF_THEN_ELSE: test for (a & (1 << BIT_NO))
+(define_insn_and_split "*branch<X:mode>_bext"
+  [(set (pc)
+	(if_then_else
+	  (match_operator 1 "equality_operator"
+         [(zero_extract:X (match_operand:X 2 "register_operand" "r")
+                          (const_int 1)
+                          (zero_extend:X
+                            (match_operand:QI 3 "register_operand" "r")))
+	    (const_int 0)])
+	(label_ref (match_operand 0 "" ""))
+	(pc)))
+  (clobber (match_scratch:X 4 "=&r"))]
+  "TARGET_ZBS"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 4) (zero_extract:X (match_dup 2)
+					(const_int 1)
+					(zero_extend:X (match_dup 3))))
+   (set (pc) (if_then_else (match_op_dup 1 [(match_dup 4) (const_int 0)])
+			   (label_ref (match_dup 0))
+			   (pc)))])
+
 ;; ZBKC or ZBC extension
 (define_insn "riscv_clmul_<mode>"
   [(set (match_operand:X 0 "register_operand" "=r")
diff --git a/gcc/testsuite/gcc.target/riscv/zbs-bext-02.c b/gcc/testsuite/gcc.target/riscv/zbs-bext-02.c
new file mode 100644
index 00000000000..3f3b8404eca
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/zbs-bext-02.c
@@ -0,0 +1,18 @@ 
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc_zbs -mabi=lp64" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-funroll-loops" } } */
+
+int
+foo(const long long B, int a)
+{
+  long long b = 1;    
+  for (int sq = 0; sq < 64; sq++)
+    if (B & (b << sq)) 
+      a++;
+
+  return a;
+}
+
+/* { dg-final { scan-assembler-times "bext\t" 1 } } */
+/* { dg-final { scan-assembler-not "bset" } } */
+/* { dg-final { scan-assembler-not "and" } } */