[PULL,34/50] disas/riscv: enable disassembly for compressed sspush/sspopchk

Commit Message

Alistair Francis Oct. 31, 2024, 3:53 a.m. UTC

From: Deepak Gupta <[e-mail]>

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 <[e-mail]>
Acked-by: Alistair Francis <[e-mail]>
Message-ID: <[e-mail]>
Signed-off-by: Alistair Francis <[e-mail]>
---
 disas/riscv.h |  1 +
 disas/riscv.c | 19 ++++++++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

Patch

diff --git a/disas/riscv.h b/disas/riscv.h
index e197f5d435..d211700cb2 100644
--- 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 */
diff --git a/disas/riscv.c b/disas/riscv.c
index 1f0eb66d01..9c1e332dde 100644
--- 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;
     };
 }