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>
qemu · Oct 6, 2021 · fd4b81a · fd4b81a
1 parent f36a4a8
commit fd4b81a
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diff --git 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;
+}
diff --git a/target/riscv/helper.h b/target/riscv/helper.h
@@ -63,6 +63,8 @@ DEF_HELPER_FLAGS_2(grev, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 DEF_HELPER_FLAGS_2(grevw, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 DEF_HELPER_FLAGS_2(gorc, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 DEF_HELPER_FLAGS_2(gorcw, TCG_CALL_NO_RWG_SE, tl, tl, tl)
+DEF_HELPER_FLAGS_2(clmul, TCG_CALL_NO_RWG_SE, tl, tl, tl)
+DEF_HELPER_FLAGS_2(clmulr, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 
 /* Special functions */
 DEF_HELPER_2(csrr, tl, env, int)

diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
@@ -714,6 +714,11 @@ roriw      0110000 .......... 101 ..... 0011011 @sh5
 greviw     0110100 .......... 101 ..... 0011011 @sh5
 gorciw     0010100 .......... 101 ..... 0011011 @sh5
 
+# *** RV32 Zbc Standard Extension ***
+clmul      0000101 .......... 001 ..... 0110011 @r
+clmulh     0000101 .......... 011 ..... 0110011 @r
+clmulr     0000101 .......... 010 ..... 0110011 @r
+
 # *** RV32 Zbs Standard Extension ***
 bclr       0100100 .......... 001 ..... 0110011 @r
 bclri      01001. ........... 001 ..... 0010011 @sh

diff --git a/target/riscv/insn_trans/trans_rvb.c.inc b/target/riscv/insn_trans/trans_rvb.c.inc
@@ -1,5 +1,5 @@
 /*
- * RISC-V translation routines for the RVB draft Zb[as] Standard Extension.
+ * RISC-V translation routines for the Zb[acs] Standard Extension.
  *
  * Copyright (c) 2020 Kito Cheng, kito.cheng@sifive.com
  * Copyright (c) 2020 Frank Chang, frank.chang@sifive.com
@@ -24,6 +24,12 @@
     }                                            \
 } while (0)
 
+#define REQUIRE_ZBC(ctx) do {                    \
+    if (!RISCV_CPU(ctx->cs)->cfg.ext_zbc) {      \
+        return false;                            \
+    }                                            \
+} while (0)
+
 #define REQUIRE_ZBS(ctx) do {                    \
     if (!RISCV_CPU(ctx->cs)->cfg.ext_zbs) {      \
         return false;                            \
@@ -535,3 +541,27 @@ static bool trans_slli_uw(DisasContext *ctx, arg_slli_uw *a)
     REQUIRE_ZBA(ctx);
     return gen_shift_imm_fn(ctx, a, EXT_NONE, gen_slli_uw);
 }
+
+static bool trans_clmul(DisasContext *ctx, arg_clmul *a)
+{
+    REQUIRE_ZBC(ctx);
+    return gen_arith(ctx, a, EXT_NONE, gen_helper_clmul);
+}
+
+static void gen_clmulh(TCGv dst, TCGv src1, TCGv src2)
+{
+     gen_helper_clmulr(dst, src1, src2);
+     tcg_gen_shri_tl(dst, dst, 1);
+}
+
+static bool trans_clmulh(DisasContext *ctx, arg_clmulr *a)
+{
+    REQUIRE_ZBC(ctx);
+    return gen_arith(ctx, a, EXT_NONE, gen_clmulh);
+}
+
+static bool trans_clmulr(DisasContext *ctx, arg_clmulh *a)
+{
+    REQUIRE_ZBC(ctx);
+    return gen_arith(ctx, a, EXT_NONE, gen_helper_clmulr);
+}