fmv.w.x

Floating-Point Move Single-Precision Word from Integer Register

The fmv.w.x instruction moves the single-precision value encoded in IEEE 754-2008 standard encoding from the lower 32 bits of integer register xs1 to the floating-point register fd. The bits are not modified in the transfer, and in particular, the payloads of non-canonical NaNs are preserved.

Assembly format

fmv.w.x fd, xs1

Decode Variables

Bits<5> xs1 = $encoding[19:15];
Bits<5> fd = $encoding[11:7];

Execution

check_f_ok($encoding);
Bits<32> sp_value = X[xs1][31:0];
if (implemented?(ExtensionName::D)) {
  F[fd] = nan_box(32, 64, sp_value);
} else {
  F[fd] = sp_value;
}
mark_f_state_dirty();

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction

Encoding

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Defining extension

F

Access

M

Always

Containing profiles

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

  • Optional: RVI20U32, RVI20U64