target/riscv: compressed encodings for sspush and sspopchk

sspush/sspopchk have compressed encodings carved out of zcmops.
compressed sspush is designated as c.mop.1 while compressed sspopchk
is designated as c.mop.5.

Note that c.sspush x1 exists while c.sspush x5 doesn't. Similarly
c.sspopchk x5 exists while c.sspopchk x1 doesn't.

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Co-developed-by: Jim Shu <jim.shu@sifive.com>
Co-developed-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241008225010.1861630-18-debug@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/insn16.decode b/target/riscv/insn16.decode
index 3953bcf82d6fc0d100624a1c51e1a32ca10853b3..bf893d1c2e9afc16d5ec1499271ab6f662dc61b7 100644 (file)
--- a/target/riscv/insn16.decode
+++ b/target/riscv/insn16.decode
@@ -140,6 +140,10 @@ sw                110  ... ... .. ... 00 @cs_w
 addi              000 .  .....  ..... 01 @ci
 addi              010 .  .....  ..... 01 @c_li
 {
+  # c.sspush x1 carving out of zcmops
+  sspush          011 0  00001  00000 01 &r2_s rs2=1 rs1=0
+  # c.sspopchk x5 carving out of zcmops
+  sspopchk        011 0  00101  00000 01 &r2 rs1=5 rd=0
   c_mop_n         011 0 0 n:3 1 00000 01
   illegal         011 0  -----  00000 01 # c.addi16sp and c.lui, RES nzimm=0
   addi            011 .  00010  ..... 01 @c_addi16sp