c.fldsp

Load doubleword into floating-point register from stack

This instruction is defined by:

  • anyOf:

    • allOf:

      • C, version >= C@2.0.0

      • D, version >= D@2.2.0

    • Zcd, version >= Zcd@1.0.0

This instruction is included in the following profiles:

  • RVA20S64 (Optional)

  • RVA20U64 (Mandatory)

  • RVA22S64 (Optional)

  • RVA22U64 (Mandatory)

  • RVA23S64 (Optional)

  • RVA23U64 (Mandatory)

  • RVB23S64 (Optional)

  • RVB23U64 (Mandatory)

  • RVI20U32 (Optional)

  • RVI20U64 (Optional)

Encoding

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Assembly format

c.fldsp fd, imm(sp)

Synopsis

Loads a double-precision floating-point value from memory into floating-point register rd. It computes its effective address by adding the zero-extended offset, scaled by 8, to the stack pointer, x2. It expands to fld rd, offset(x2).

Access

M HS U VS VU

Always

Always

Always

Always

Always

Decode Variables

Bits<9> imm = {$encoding[4:2], $encoding[12], $encoding[6:5], 3'd0};
Bits<5> rd = $encoding[11:7];

Execution

  • IDL

if (implemented?(ExtensionName::C) && (CSR[misa].C == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
if (implemented?(ExtensionName::D) && (CSR[misa].D == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg virtual_address = X[2] + imm;
f[rd] = read_memory<64>(virtual_address, $encoding);

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction

  • LoadAccessFault

  • LoadAddressMisaligned

  • LoadPageFault