ztrans_proposal.mdwn

   1 # Ztrans - transcendental operations
   2
   3 See:
   4
   5 * <http://bugs.libre-riscv.org/show_bug.cgi?id=127>
   6 * <https://www.khronos.org/registry/spir-v/specs/unified1/OpenCL.ExtendedInstructionSet.100.html>
   7
   8 [[!toc levels=2]]
   9
  10 # List of 2-arg opcodes
  11
  12 [[!table  data="""
  13 opcode    | Description           | pseudo-code                | Extension |
  14 FATAN2    | atan2 arc tangent     | rd = atan2(rs2, rs1)       | Ztrans    |
  15 FATAN2PI  | atan arc tangent / pi | rd = atan2(rs2, rs1) / pi  |           |
  16 FPOW      | power of              | rd = pow(rs1, rs2)         | Ztrans    |
  17 """]]
  18
  19 # List of 1-arg opcodes
  20
  21 [[!table  data="""
  22 opcode   | Description              | pseudo-code             | Extension |
  23 FCBRT    | Cube Root                | rd = pow(rs1, 3)        |           |
  24 FEXP2    | power-of-2               | rd = pow(2, rs1)        |           |
  25 FLOG2    | log2                     | rd = log2(rs1)          |           |
  26 FEXPM1   | exponent minus 1         | rd = pow(e, rs1) - 1.0  |           |
  27 FLOG1P   | log plus 1               | rd = log(e, 1 + rs1)    |           |
  28 FEXP     | exponent                 | rd = pow(e, rs1)        |           |
  29 FLOG     | natural log (base e)     | rd = log(e, rs1)        |           |
  30 FEXP10   | power-of-10              | rd = pow(10, rs1)       |           |
  31 FLOG10   | log base 10              | rd = log10(rs1)         |           |
  32 FSIN     | sin (radians)            |                         | Ztrans    |
  33 FCOS     | cos (radians)            |                         | Ztrans    |
  34 FTAN     | tan (radians)            |                         | Ztrans    |
  35 FSINPI   | sin times pi             | rd = sin(pi * rs1)      |           |
  36 FCOSPI   | cos times pi             | rd = cos(pi * rs1)      |           |
  37 FTANPI   | tan times pi             | rd = tan(pi * rs1)      |           |
  38 FSINH    | hyperbolic sin (radians) |                         |           |
  39 FCOSH    | hyperbolic cos (radians) |                         |           |
  40 FTANH    | hyperbolic tan (radians) |                         |           |
  41 FASINH   | inverse hyperbolic sin   |                         |           |
  42 FACOSH   | inverse hyperbolic cos   |                         |           |
  43 FATANH   | inverse hyperbolic tan   |                         |           |
  44 """]]
  45
  46 # Pseudo-code ops
  47
  48 * FRCP rd, rs1 - pseudo-code alias for rd = 1.0 / rs1
  49 * SINCOS - fused macro-op between FSIN and FCOS (issued in that order).
  50 * SINCOSPI - fused macro-op between FSINPI and FCOSPI (issued in that order).
  51