disas/riscv: enable disassembly for compressed sspush/sspopchk

sspush and sspopchk have equivalent compressed encoding taken from zcmop.
cmop.1 is sspush x1 while cmop.5 is sspopchk x5. Due to unusual encoding
for both rs1 and rs2 from space bitfield, this required a new codec.

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241008225010.1861630-20-debug@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/disas/riscv.c b/disas/riscv.c
index 1f0eb66d01c1176ebf397aaa54b7fb9775b0af16..9c1e332ddea9dcd65b23d0acf69e7075127808fc 100644 (file)
--- a/disas/riscv.c
+++ b/disas/riscv.c
@@ -982,6 +982,8 @@ typedef enum {
     rv_op_ssrdp = 951,
     rv_op_ssamoswap_w = 952,
     rv_op_ssamoswap_d = 953,
+    rv_op_c_sspush = 954,
+    rv_op_c_sspopchk = 955,
 } rv_op;
 
 /* register names */
@@ -2248,6 +2250,10 @@ const rv_opcode_data rvi_opcode_data[] = {
     { "ssrdp", rv_codec_r, rv_fmt_rd, NULL, 0, 0, 0 },
     { "ssamoswap.w", rv_codec_r_a, rv_fmt_aqrl_rd_rs2_rs1, NULL, 0, 0, 0 },
     { "ssamoswap.d", rv_codec_r_a, rv_fmt_aqrl_rd_rs2_rs1, NULL, 0, 0, 0 },
+    { "c.sspush", rv_codec_cmop_ss, rv_fmt_rs2, NULL, rv_op_sspush,
+      rv_op_sspush, 0 },
+    { "c.sspopchk", rv_codec_cmop_ss, rv_fmt_rs1, NULL, rv_op_sspopchk,
+      rv_op_sspopchk, 0 },
 };
 
 /* CSR names */
@@ -2608,7 +2614,13 @@ static void decode_inst_opcode(rv_decode *dec, rv_isa isa)
             if (dec->cfg->ext_zcmop) {
                 if ((((inst >> 2) & 0b111111) == 0b100000) &&
                     (((inst >> 11) & 0b11) == 0b0)) {
-                    op = rv_c_mop_1 + ((inst >> 8) & 0b111);
+                    unsigned int cmop_code = 0;
+                    cmop_code = ((inst >> 8) & 0b111);
+                    op = rv_c_mop_1 + cmop_code;
+                    if (dec->cfg->ext_zicfiss) {
+                        op = (cmop_code == 0) ? rv_op_c_sspush : op;
+                        op = (cmop_code == 2) ? rv_op_c_sspopchk : op;
+                    }
                     break;
                 }
             }
@@ -4929,6 +4941,11 @@ static void decode_inst_operands(rv_decode *dec, rv_isa isa)
     case rv_codec_lp:
         dec->imm = operand_lpl(inst);
         break;
+    case rv_codec_cmop_ss:
+        dec->rd = rv_ireg_zero;
+        dec->rs1 = dec->rs2 = operand_crs1(inst);
+        dec->imm = 0;
+        break;
     };
 }
 

diff --git a/disas/riscv.h b/disas/riscv.h
index e197f5d435d9b2f8ff2029445adadad7faa52490..d211700cb2f6c8d20b475ff4d03a909239c79131 100644 (file)
--- a/disas/riscv.h
+++ b/disas/riscv.h
@@ -167,6 +167,7 @@ typedef enum {
     rv_codec_r2_imm2_imm5,
     rv_codec_fli,
     rv_codec_lp,
+    rv_codec_cmop_ss,
 } rv_codec;
 
 /* structures */