c.flw

Load single-precision

Loads a single precision floating-point value from memory into register fd. It computes an effective address by adding the zero-extended offset, scaled by 4, to the base address in register xs1. It expands to flw fd, offset(xs1).

Assembly format

c.flw fd, imm(rs1)

Decode Variables

Bits<7> imm = {$encoding[5], $encoding[12:10], $encoding[6], 2'd0};
Bits<3> fd = $encoding[4:2];
Bits<3> xs1 = $encoding[9:7];

Execution

  • IDL

if (implemented?(ExtensionName::C) && (misa.C == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg virtual_address = X[creg2reg(xs1)] + imm;
X[creg2reg(fd)] = sext(read_memory<32>(virtual_address, $encoding), 32);

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction

  • LoadAccessFault

  • LoadAddressMisaligned

  • LoadPageFault

Encoding

svg

Defining extension

  • anyOf:

    • allOf:

      • C, version >= C@2.0.0

      • F, version >= F@2.2.0

    • Zcf, version >= Zcf@1.0.0

Access

M HS U VS VU

Always

Always

Always

Always

Always

Containing profiles

  • Mandatory: RVA20S64, RVA20U64, RVA22S64, RVA22U64, RVA23M64, RVA23S64, RVA23U64, RVB23M64, RVB23S64, RVB23U64

  • Optional: RVI20U32, RVI20U64