From d328d3a6f8756ed61b3cdf3675b24051f7d3b2ef Mon Sep 17 00:00:00 2001
From: =?utf8?q?Christoph=20M=C3=BCllner?= <christoph.muellner@vrull.eu>
Date: Mon, 5 Dec 2022 13:02:24 +0100
Subject: [PATCH] riscv: thead: Add support for the XTheadBs ISA extension
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This patch adds support for the XTheadBs ISA extension.
The new INSN pattern is defined in a new file to separate
this vendor extension from the standard extensions.
The cost model adjustment reuses the xbs:bext cost.

gcc/ChangeLog:

	* config/riscv/riscv.cc (riscv_rtx_costs): Add xthead:tst cost.
	* config/riscv/thead.md (*th_tst<mode>3): New INSN.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/xtheadbs-tst.c: New test.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
---
 gcc/config/riscv/riscv.cc                     |  4 ++--
 gcc/config/riscv/thead.md                     | 11 +++++++++++
 gcc/testsuite/gcc.target/riscv/xtheadbs-tst.c | 13 +++++++++++++
 3 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/xtheadbs-tst.c

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index c91fa31..69fb789 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -2412,8 +2412,8 @@ riscv_rtx_costs (rtx x, machine_mode mode, int outer_code, int opno ATTRIBUTE_UN
 	  *total = COSTS_N_INSNS (SINGLE_SHIFT_COST);
 	  return true;
 	}
-      /* bext pattern for zbs.  */
-      if (TARGET_ZBS && outer_code == SET
+      /* bit extraction pattern (zbs:bext, xtheadbs:tst).  */
+      if ((TARGET_ZBS || TARGET_XTHEADBS) && outer_code == SET
 	  && GET_CODE (XEXP (x, 1)) == CONST_INT
 	  && INTVAL (XEXP (x, 1)) == 1)
 	{
diff --git a/gcc/config/riscv/thead.md b/gcc/config/riscv/thead.md
index 2da5aaee..3842a19 100644
--- a/gcc/config/riscv/thead.md
+++ b/gcc/config/riscv/thead.md
@@ -29,3 +29,14 @@
   "th.addsl\t%0,%3,%1,%2"
   [(set_attr "type" "bitmanip")
    (set_attr "mode" "<X:MODE>")])
+
+;; XTheadBs
+
+(define_insn "*th_tst<mode>3"
+  [(set (match_operand:X 0 "register_operand" "=r")
+	(zero_extract:X (match_operand:X 1 "register_operand" "r")
+			(const_int 1)
+			(match_operand 2 "const_int_operand" "n")))]
+  "TARGET_XTHEADBS && UINTVAL (operands[2]) < GET_MODE_BITSIZE (<MODE>mode)"
+  "th.tst\t%0,%1,%2"
+  [(set_attr "type" "bitmanip")])
diff --git a/gcc/testsuite/gcc.target/riscv/xtheadbs-tst.c b/gcc/testsuite/gcc.target/riscv/xtheadbs-tst.c
new file mode 100644
index 0000000..674cec0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/xtheadbs-tst.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv32gc_xtheadbs" { target { rv32 } } } */
+/* { dg-options "-march=rv64gc_xtheadbs" { target { rv64 } } } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+long
+foo1 (long i)
+{
+  return 1L & (i >> 20);
+}
+
+/* { dg-final { scan-assembler-times "th.tst\t" 1 } } */
+/* { dg-final { scan-assembler-not "andi" } } */
-- 
2.7.4