target/riscv: Add instructions of the Zbc-extension

The following instructions are part of Zbc:
 - clmul
 - clmulh
 - clmulr

Note that these instructions were already defined in the pre-0.93 and
the 0.93 draft-B proposals, but had not been omitted in the earlier
addition of draft-B to QEmu.

Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210911140016.834071-10-philipp.tomsich@vrull.eu
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/target/riscv/bitmanip_helper.c b/target/riscv/bitmanip_helper.c
index 5b2f795d03..73be5a81c7 100644
--- a/target/riscv/bitmanip_helper.c
+++ b/target/riscv/bitmanip_helper.c
@@ -3,6 +3,7 @@
  *
  * Copyright (c) 2020 Kito Cheng, kito.cheng@sifive.com
  * Copyright (c) 2020 Frank Chang, frank.chang@sifive.com
+ * Copyright (c) 2021 Philipp Tomsich, philipp.tomsich@vrull.eu
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -88,3 +89,29 @@ target_ulong HELPER(gorcw)(target_ulong rs1, target_ulong rs2)
 {
     return do_gorc(rs1, rs2, 32);
 }
+
+target_ulong HELPER(clmul)(target_ulong rs1, target_ulong rs2)
+{
+    target_ulong result = 0;
+
+    for (int i = 0; i < TARGET_LONG_BITS; i++) {
+        if ((rs2 >> i) & 1) {
+            result ^= (rs1 << i);
+        }
+    }
+
+    return result;
+}
+
+target_ulong HELPER(clmulr)(target_ulong rs1, target_ulong rs2)
+{
+    target_ulong result = 0;
+
+    for (int i = 0; i < TARGET_LONG_BITS; i++) {
+        if ((rs2 >> i) & 1) {
+            result ^= (rs1 >> (TARGET_LONG_BITS - i - 1));
+        }
+    }
+
+    return result;
+}