rv_major_opcode_1010011.mdwn

   1 # Summary FP Opcodes
   2
   3 This page aids and assists in the development of FP proposals,
   4 by identifying and listing in full both publicly-known proposals
   5 and the full brownfield encoding space available in the 0b010011
   6 major opcode.
   7
   8 A primary critical use-case for extending FP is for 3D and supercomputing.
   9
  10 Publicly-known FP proposals:
  11
  12 * Zfrsqrt - Reciprocal SQRT <http://bugs.libre-riscv.org/show_bug.cgi?id=110>
  13 * Zftrans - Transcendentals (FSIN, FCOS, FATAN, FPOW, FEXP, FLOG, FRCP)
  14 * Extension of formats to cover FP16 (RISC-V ISA Manual Table 11.3 "fmt field")
  15 * HI-half FP MV - <https://github.com/riscv/riscv-isa-manual/pull/301>
  16   <https://groups.google.com/a/groups.riscv.org/forum/m/#!topic/isa-dev/kXgfFqgBv-c>
  17 * (Add new entries here: Zextname - Description and URL)
  18
  19 [[!toc levels=2]]
  20
  21 # Main FP opcode 1010011 table
  22
  23 Notes:
  24
  25 * Proposed new encodings in **bold**.
  26 * *Use funct5 sparingly!* - 2-operand functions only.
  27 * Single-argument FP operations should go under one of the funct5 tables
  28 * Both dual and single argument FP operations that do not require
  29   "rounding mode" should go in one of the funct5 tables that already use
  30   "funct3".
  31 * Be careful not to use encoding space for which FP16 has already been
  32   reserved.
  33
  34 [[!table  data="""
  35 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
  36 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
  37  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
  38 00000   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FADD.xx     |
  39 00001   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FSUB.xx     |
  40 00010   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FMUL.xx     |
  41 00011   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FDIV.xx     |
  42 00100   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  43 00101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | tb=00101    |
  44 00110   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  45 00111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  46 01000   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | tb=01000    |
  47 01001   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  48 01010   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  49 01011   | xx      | xxxxx  | rs1  | yyy    | rd    | 1010011 | tb=01011    |
  50 01100   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  51 01101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  52 01110   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  53 01111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | **FPOW.xx** |
  54 10000   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  55 10001   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  56 10010   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  57 10011   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  58 10100   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | tb=10100    |
  59 10101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  60 10110   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  61 10111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  62 11000   | xx      | xxxxx  | rs1  | yyy    | rd    | 1010011 | tb=11000    |
  63 11001   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  64 11010   | xx      | xxxxx  | rs1  | yyy    | rd    | 1010011 | tb=11010    |
  65 11100   | xx      | xxxxx  | rs1  | 000    | rd    | 1010011 | tb=11100    |
  66 11101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  67 11110   | xx      | xxxxx  | rs1  | 000    | rd    | 1010011 | tb=11110    |
  68 11111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  69 """]]
  70
  71 ## funct5 = 00000 - FADD
  72
  73 No brownfield encodings available.
  74
  75 ## funct5 = 00001 - FSUB
  76
  77 No brownfield encodings available.
  78
  79 ## funct5 = 00010 - FMUL
  80
  81 No brownfield encodings available.
  82
  83 ## funct5 = 00011 - FDIV
  84
  85 No brownfield encodings available.
  86
  87 ## funct5 = 00100 - unused
  88
  89 Brownfield encodings available.
  90
  91 ## funct5 = 00100
  92
  93 This table uses funct3 for encoding 2-operand FP operations
  94
  95 [[!table  data="""
  96 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
  97 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
  98  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
  99 00100   | xx      | rs2    | rs1  | 000    | rd    | 1010011 | FSGNJ.xx    |
 100 00100   | xx      | rs2    | rs1  | 001    | rd    | 1010011 | FSGNJN.xx   |
 101 00100   | xx      | rs2    | rs1  | 010    | rd    | 1010011 | FSGNJX.xx   |
 102 00100   | xx      | rs2    | rs1  | 011    | rd    | 1010011 | ?f3=011     |
 103 00100   | xx      | rs2    | rs1  | 100    | rd    | 1010011 | ?f3=100     |
 104 00100   | xx      | rs2    | rs1  | 101    | rd    | 1010011 | ?f3=101     |
 105 00100   | xx      | rs2    | rs1  | 110    | rd    | 1010011 | ?f3=110     |
 106 00100   | xx      | rs2    | rs1  | 111    | rd    | 1010011 | ?f3=111     |
 107 """]]
 108
 109 ## funct5 = 00101
 110
 111 This table uses funct3 for encoding 2-operand FP operations where the result
 112 register is a **floating-point** value.
 113
 114 [[!table  data="""
 115 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 116 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 117  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 118 00101   | xx      | rs2    | rs1  | 000    | rd    | 1010011 | FMIN.S      |
 119 00101   | xx      | rs2    | rs1  | 001    | rd    | 1010011 | FMAX.S      |
 120 00101   | xx      | rs2    | rs1  | 010    | rd    | 1010011 | ?f3=010     |
 121 00101   | xx      | rs2    | rs1  | 011    | rd    | 1010011 | ?f3=011     |
 122 00101   | xx      | rs2    | rs1  | 100    | rd    | 1010011 | ?f3=100     |
 123 00101   | xx      | rs2    | rs1  | 101    | rd    | 1010011 | ?f3=101     |
 124 00101   | xx      | rs2    | rs1  | 110    | rd    | 1010011 | ?f3=110     |
 125 00101   | xx      | rs2    | rs1  | 111    | rd    | 1010011 | ?f3=111     |
 126 """]]
 127
 128 ## funct5 = 00110 - unused
 129
 130 Brownfield encodings available.
 131
 132 ## funct5 = 00111 - unused
 133
 134 Brownfield encodings available.
 135
 136 ## funct5 = 01000
 137
 138 This table uses rs2 for encoding 1-operand FP operations, using
 139 funct3 to specify the "rounding" mode
 140
 141 Notes:
 142
 143 * FP16 logically deduced from fmt field encoding (bits 25-26)
 144
 145 [[!table  data="""
 146 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 147 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 148  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 149 01000   | 00      | 00000  | rs1  | rm     | rd    | 1010011 | ????????    |
 150 01000   | 00      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.S.D    |
 151 01000   | 00      | 00010  | rs1  | rm     | rd    | 1010011 | **FCVT.S.H**|
 152 01000   | 00      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.S.Q    |
 153 01000   | 00      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 154 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 155 01000   | 01      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.D.S    |
 156 01000   | 01      | 00001  | rs1  | rm     | rd    | 1010011 | ????????    |
 157 01000   | 01      | 00010  | rs1  | rm     | rd    | 1010011 | **FCVT.D.H**|
 158 01000   | 01      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.D.Q    |
 159 01000   | 01      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 160 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 161 01000   | 10      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.H.S    |
 162 01000   | 10      | 00001  | rs1  | rm     | rd    | 1010011 | **FCVT.H.D**|
 163 01000   | 10      | 00010  | rs1  | rm     | rd    | 1010011 | ????????    |
 164 01000   | 10      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.H.Q    |
 165 01000   | 10      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 166 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 167 01000   | 11      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.Q.S    |
 168 01000   | 11      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.Q.D    |
 169 01000   | 11      | 00010  | rs1  | rm     | rd    | 1010011 | **FCVT.Q.H**|
 170 01000   | 11      | 00011  | rs1  | rm     | rd    | 1010011 | ????????    |
 171 01000   | 11      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 172 """]]
 173
 174 ## funct5 = 01001 - unused
 175
 176 Brownfield encodings available.
 177
 178 ## funct5 = 01010 - unused
 179
 180 Brownfield encodings available.
 181
 182 ## funct5 = 01011
 183
 184 This table uses rs2 for encoding 1-operand FP operations, using
 185 funct3 to specify the "rounding" mode
 186
 187 [[!table  data="""
 188 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function      |
 189 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name          |
 190  5      | 2       | 5      | 5    | 3      | 5     |   7     |               |
 191 01011   | xx      | 00000  | rs1  | rm     | rd    | 1010011 | FSQRT.xx      |
 192 01011   | xx      | 00001  | rs1  | rm     | rd    | 1010011 | **FRSQRT.xx** |
 193 01011   | xx      | 00010  | rs1  | rm     | rd    | 1010011 | **FSIN.xx**   |
 194 01011   | xx      | 00011  | rs1  | rm     | rd    | 1010011 | **FCOS.xx**   |
 195 01011   | xx      | 00100  | rs1  | rm     | rd    | 1010011 | **FATAN.xx**  |
 196 01011   | xx      | 00101  | rs1  | rm     | rd    | 1010011 | **FEXP.xx**   |
 197 01011   | xx      | 00110  | rs1  | rm     | rd    | 1010011 | **FLOG.xx**   |
 198 01011   | xx      | 00111  | rs1  | rm     | rd    | 1010011 | **FRCP.xx**   |
 199 01011   | xx      | 01000  | rs1  | rm     | rd    | 1010011 | ?             |
 200 01011   | xx      | 01001  | rs1  | rm     | rd    | 1010011 | ?             |
 201 01011   | xx      | 01010  | rs1  | rm     | rd    | 1010011 | ?             |
 202 01011   | xx      | 01011  | rs1  | rm     | rd    | 1010011 | ?             |
 203 01011   | xx      | 01100  | rs1  | rm     | rd    | 1010011 | ?             |
 204 01011   | xx      | 01101  | rs1  | rm     | rd    | 1010011 | ?             |
 205 01011   | xx      | 01110  | rs1  | rm     | rd    | 1010011 | ?             |
 206 01011   | xx      | 01111  | rs1  | rm     | rd    | 1010011 | ?             |
 207 01011   | xx      | 10000  | rs1  | rm     | rd    | 1010011 | ?             |
 208 01011   | xx      | 10001  | rs1  | rm     | rd    | 1010011 | ?             |
 209 01011   | xx      | 10010  | rs1  | rm     | rd    | 1010011 | ?             |
 210 01011   | xx      | 10011  | rs1  | rm     | rd    | 1010011 | ?             |
 211 01011   | xx      | 10100  | rs1  | rm     | rd    | 1010011 | ?             |
 212 01011   | xx      | 10101  | rs1  | rm     | rd    | 1010011 | ?             |
 213 01011   | xx      | 10110  | rs1  | rm     | rd    | 1010011 | ?             |
 214 01011   | xx      | 10111  | rs1  | rm     | rd    | 1010011 | ?             |
 215 01011   | xx      | 11000  | rs1  | rm     | rd    | 1010011 | ?             |
 216 01011   | xx      | 11001  | rs1  | rm     | rd    | 1010011 | ?             |
 217 01011   | xx      | 11010  | rs1  | rm     | rd    | 1010011 | ?             |
 218 01011   | xx      | 11011  | rs1  | rm     | rd    | 1010011 | ?             |
 219 01011   | xx      | 11100  | rs1  | rm     | rd    | 1010011 | ?             |
 220 01011   | xx      | 11101  | rs1  | rm     | rd    | 1010011 | ?             |
 221 01011   | xx      | 11110  | rs1  | rm     | rd    | 1010011 | ?             |
 222 01011   | xx      | 11111  | rs1  | rm     | rd    | 1010011 | ?             |
 223 """]]
 224
 225 ## funct5 = 01100 - unused
 226
 227 Brownfield encodings available.
 228
 229 ## funct5 = 01101 - unused
 230
 231 Brownfield encodings available.
 232
 233 ## funct5 = 01110 - unused
 234
 235 Brownfield encodings available.
 236
 237 ## funct5 = 01111 - **FPOW**
 238
 239 Proposed for Zftrans - FPOW: "FP rs2 to the power of rs1"
 240
 241 ## funct5 = 10000 - unused
 242
 243 Brownfield encodings available.
 244
 245 ## funct5 = 10001 - unused
 246
 247 Brownfield encodings available.
 248
 249 ## funct5 = 10010 - unused
 250
 251 Brownfield encodings available.
 252
 253 ## funct5 = 10011 - unused
 254
 255 Brownfield encodings available.
 256
 257 ## funct5 = 10100
 258
 259 This table uses funct3 for encoding 2-operand FP "comparison" operations
 260 where the result register is an **integer**
 261
 262 Notes:
 263
 264 * FNE missing?
 265
 266 [[!table  data="""
 267 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 268 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 269  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 270 10100   | xx      | rs2    | rs1  | 000    | rd    | 1010011 | FLE.xx      |
 271 10100   | xx      | rs2    | rs1  | 001    | rd    | 1010011 | FLT.xx      |
 272 10100   | xx      | rs2    | rs1  | 010    | rd    | 1010011 | FEQ.xx      |
 273 10100   | xx      | rs2    | rs1  | 011    | rd    | 1010011 | ?f3=011     |
 274 10100   | xx      | rs2    | rs1  | 100    | rd    | 1010011 | ?f3=100     |
 275 10100   | xx      | rs2    | rs1  | 101    | rd    | 1010011 | ?f3=101     |
 276 10100   | xx      | rs2    | rs1  | 110    | rd    | 1010011 | ?f3=110     |
 277 10100   | xx      | rs2    | rs1  | 111    | rd    | 1010011 | ?f3=111     |
 278 """]]
 279
 280 ## funct5 = 10101 - unused
 281
 282 Brownfield encodings available.
 283
 284 ## funct5 = 10110 - unused
 285
 286 Brownfield encodings available.
 287
 288 ## funct5 = 10111 - unused
 289
 290 Brownfield encodings available.
 291
 292 ## funct5 = 11000
 293
 294 This table uses rs2 for encoding 1-operand FP operations, using
 295 funct3 to specify the "rounding" mode
 296
 297 Notes:
 298
 299 * FP16 logically deduced from fmt field (bits 25-26)
 300
 301 [[!table  data="""
 302 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 303 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 304  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 305 11000   | 00      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.W.S    |
 306 11000   | 00      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.WU.S   |
 307 11000   | 00      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.L.S    |
 308 11000   | 00      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.LU.S   |
 309 11000   | 00      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 310 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 311 11000   | 01      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.W.D    |
 312 11000   | 01      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.WU.D   |
 313 11000   | 01      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.L.D    |
 314 11000   | 01      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.LU.D   |
 315 11000   | 01      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 316 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 317 11000   | 10      | 00000  | rs1  | rm     | rd    | 1010011 |**FCVT.W.H** |
 318 11000   | 10      | 00001  | rs1  | rm     | rd    | 1010011 |**FCVT.WU.H**|
 319 11000   | 10      | 00010  | rs1  | rm     | rd    | 1010011 |**FCVT.L.H** |
 320 11000   | 10      | 00011  | rs1  | rm     | rd    | 1010011 |**FCVT.LU.H**|
 321 11000   | 10      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 322 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 323 11000   | 11      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.W.Q    |
 324 11000   | 11      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.WU.Q   |
 325 11000   | 11      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.L.Q    |
 326 11000   | 11      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.LU.Q   |
 327 11000   | 11      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 328 """]]
 329
 330 ## funct5 = 11001 - unused
 331
 332 Brownfield encodings available.
 333
 334 ## funct5 = 11010
 335
 336 This table uses rs2 for encoding 1-operand FP operations, using
 337 funct3 to specify the "rounding" mode
 338
 339 * FP16 logically deduced from fmt field (bits 25-26)
 340
 341 [[!table  data="""
 342 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 343 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 344  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 345 11010   | 00      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.S.W    |
 346 11010   | 00      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.S.WU   |
 347 11010   | 00      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.S.L    |
 348 11010   | 00      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.S.LU   |
 349 11010   | 00      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 350 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 351 11010   | 01      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.D.W    |
 352 11010   | 01      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.D.WU   |
 353 11010   | 01      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.D.L    |
 354 11010   | 01      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.D.LU   |
 355 11010   | 01      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 356 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 357 11010   | 10      | 00000  | rs1  | rm     | rd    | 1010011 |**FCVT.H.W** |
 358 11010   | 10      | 00001  | rs1  | rm     | rd    | 1010011 |**FCVT.H.WU**|
 359 11010   | 10      | 00010  | rs1  | rm     | rd    | 1010011 |**FCVT.H.L** |
 360 11010   | 10      | 00011  | rs1  | rm     | rd    | 1010011 |**FCVT.H.LU**|
 361 11010   | 10      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 362 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 363 11010   | 11      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.Q.W    |
 364 11010   | 11      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.Q.WU   |
 365 11010   | 11      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.Q.L    |
 366 11010   | 11      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.Q.LU   |
 367 11010   | 11      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 368 """]]
 369
 370 ## funct5 = 11100
 371
 372 This table uses *both* rs2 *and* funct3 for encoding 1-operand FP operations.
 373
 374 Notes:
 375
 376 * FMV.X.Q is missing (alias of FMVH.X.D if it existed)
 377 * FP16 logically deduced from fmt field (bits 25-26)
 378 * FMVH.X.HW (half-word) missing?
 379
 380 [[!table  data="""
 381 31..27| 26..25| 24..20 |19..15|14...12| 11..7 | 6....0  | function    |
 382 funct5| SDHQ  | rs2    | rs1  |funct3 | rd    | opcode  | name        |
 383  5    | 2     | 5      | 5    | 3     | 5     |   7     |             |
 384 11100 | 00    | 00000  | rs1  | 000   | rd    | 1010011 | FMV.X.W     |
 385 11100 | 00    | 00000  | rs1  | 001   | rd    | 1010011 | FCLASS.S    |
 386 11100 | 00    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 387 ------| ----- | -----  | -----| ----- | ----- | ------- | --------    |
 388 11100 | 01    | 00000  | rs1  | 000   | rd    | 1010011 | FMV.X.D **FMVH.X.W** |
 389 11100 | 01    | 00000  | rs1  | 001   | rd    | 1010011 | FCLASS.D    |
 390 11100 | 01    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 391 ------| ----- | -----  | -----| ----- | ----- | ------- | --------    |
 392 11100 | 10    | 00000  | rs1  | 000   | rd    | 1010011 |**FMV.X.H**  |
 393 11100 | 10    | 00000  | rs1  | 001   | rd    | 1010011 |**FCLASS.H** |
 394 11100 | 10    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 395 ------| ----- | -----  | -----| ----- | ----- | ------- | --------    |
 396 11100 | 11    | 00000  | rs1  | 000   | rd    | 1010011 | **FMVH.X.D** |
 397 11100 | 11    | 00000  | rs1  | 001   | rd    | 1010011 | FCLASS.Q    |
 398 11100 | xx    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 399 """]]
 400
 401 ## funct5 = 11101 - unused
 402
 403 Brownfield encodings available.
 404
 405 ## funct5 = 11110
 406
 407 This table uses *both* rs2 *and* funct3 for encoding 1-operand FP operations.
 408
 409 Notes:
 410
 411 * FMV.Q.X is missing (as is FMVH.D.X)
 412 * FMVH.W.X is missing (alias of FMV.D.X)
 413 * FP16 logically deduced from fmt field (bits 25-26)
 414 * FMVH.HW.X (half-word) missing?
 415
 416 [[!table  data="""
 417 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 418 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 419  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 420 11110   | 00      | 00000  | rs1  | 000    | rd    | 1010011 | FMV.W.X     |
 421 11110   | 00      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 422 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 423 11110   | 01      | 00000  | rs1  | 000    | rd    | 1010011 | FMV.D.X     |
 424 11110   | 01      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 425 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 426 11110   | 10      | 00000  | rs1  | 000    | rd    | 1010011 |**FMV.H.X**  |
 427 11110   | 10      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 428 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 429 11110   | 11      | 00000  | rs1  | 000    | rd    | 1010011 | ?           |
 430 11110   | 11      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 431 """]]
 432
 433 ## funct5 = 11111 - unused
 434
 435 Brownfield encodings available.
 436
 437 ## funct5 = ????? (table template)
 438
 439 This table acts as a cut/paste template for creating brownfield encodings
 440
 441 [[!table  data="""
 442 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 443 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 444  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 445 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 446 """]]
 447