Why mapping doesn't take function

[rez5427]

I want to implement cm.push, but I've encountered a challenge: using mapping to assemble this instruction would take hundreds of lines. Any suggestions?

mapping clause assembly = CM_PUSH(rlist, spimm) if (sizeof(xlen) == 32) <->
  "cm.push" ^ spc() ^ zcmp_assembly_mapping_32(rlist, spimm) if (sizeof(xlen) == 32)

mapping zcmp_assembly_mapping_32 : (bits(4), bits(2)) <-> string = {
  (0x4, i) <-> "{ra}, " ^ "-" ^ BitStr(to_bits(xlen, i << 5)),
  (0x4, 0b01) <-> "{ra}, -32",
  (0x4, 0b10) <-> "{ra}, -48",
  (0x4, 0b11) <-> "{ra}, -64",
  (0x5, 0b00) <-> "{ra, s0}, -16",
  (0x5, 0b01) <-> "{ra, s0}, -32",
  (0x5, 0b10) <-> "{ra, s0}, -48",
  (0x5, 0b11) <-> "{ra, s0}, -64",
  (0x6, 0b00) <-> "{ra, s0-s1}, -16",
  (0x6, 0b01) <-> "{ra, s0-s1}, -32",
  (0x6, 0b10) <-> "{ra, s0-s1}, -48",
  (0x6, 0b11) <-> "{ra, s0-s1}, -64",
  (0x7, 0b00) <-> "{ra, s0-s2}, -16",
  (0x7, 0b01) <-> "{ra, s0-s2}, -32",
  (0x7, 0b10) <-> "{ra, s0-s2}, -48",
  (0x7, 0b11) <-> "{ra, s0-s2}, -64",
  (0x8, 0b00) <-> "{ra, s0-s3}, -32",
  (0x8, 0b01) <-> "{ra, s0-s3}, -48",
  (0x8, 0b10) <-> "{ra, s0-s3}, -64",
  (0x8, 0b11) <-> "{ra, s0-s3}, -80",
  (0x9, 0b00) <-> "{ra, s0-s4}, -32",
  (0x9, 0b01) <-> "{ra, s0-s4}, -48",
  (0x9, 0b10) <-> "{ra, s0-s4}, -64",
  (0x9, 0b11) <-> "{ra, s0-s4}, -80",
  (0xa, 0b00) <-> "{ra, s0-s5}, -32",
  (0xa, 0b01) <-> "{ra, s0-s5}, -48",
  (0xa, 0b10) <-> "{ra, s0-s5}, -64",
  (0xa, 0b11) <-> "{ra, s0-s5}, -80",
  (0xb, 0b00) <-> "{ra, s0-s6}, -32",
  (0xb, 0b01) <-> "{ra, s0-s6}, -48",
  (0xb, 0b10) <-> "{ra, s0-s6}, -64",
  (0xb, 0b11) <-> "{ra, s0-s6}, -80",
  (0xc, 0b00) <-> "{ra, s0-s7}, -48",
  (0xc, 0b01) <-> "{ra, s0-s7}, -64",
  (0xc, 0b10) <-> "{ra, s0-s7}, -80",
  (0xc, 0b11) <-> "{ra, s0-s7}, -96",
  (0xd, 0b00) <-> "{ra, s0-s8}, -48",
  (0xd, 0b01) <-> "{ra, s0-s8}, -64",
  (0xd, 0b10) <-> "{ra, s0-s8}, -80",
  (0xd, 0b11) <-> "{ra, s0-s8}, -96",
  (0xe, 0b00) <-> "{ra, s0-s9}, -48",
  (0xe, 0b01) <-> "{ra, s0-s9}, -64",
  (0xe, 0b10) <-> "{ra, s0-s9}, -80",
  (0xe, 0b11) <-> "{ra, s0-s9}, -96",
  (0xf, 0b00) <-> "{ra, s0-11}, -64",
  (0xf, 0b01) <-> "{ra, s0-11}, -80",
  (0xf, 0b10) <-> "{ra, s0-11}, -96",
  (0xf, 0b11) <-> "{ra, s0-11}, -112",
}

[rmn30]

Mappings can only call other mappings because they have to be reversible and functions don't necessarily have an inverse. Most of the other assembly mappings use, for example, hex_bits_signed_5 for immediate integers. Could you try that? I'm not sure if there are decimal equivalents.

[rmn30]

In this case I think you could have a mapping:

mapping zcmp_spimm_assembly_4_7_32 : bits(2) <-> string = {
  0b00 <-> "-16",
  0b01 <-> "-32",
  0b10 <-> "-48",
  0b11 <-> "-64",
}

and call this from the assembly mapping for rlist values 5-7 (not sure about 4?). You could define others for the other spimm mappings for 8-b, c-e and f? This would help a bit but it's still a bit verbose. You might be able to get more clever with some arithmetic.