FCLASS.D

Float Classify (Double)

FCLASS.D rd, rs1

Examines a double-precision register and generates a classification bitmask.

Details

Classifies the double-precision (64-bit) floating-point value in rs1, writing a 10-bit one-hot result to integer rd. Bits represent: negative infinity, negative normal, negative subnormal, negative zero, positive zero, positive subnormal, positive normal, positive infinity, signalling NaN, quiet NaN.

Pseudocode Operation

R[rd] = classify_double(F[rs1]);

Example

FCLASS.D x10, f0

Encoding

Binary Layout
1110001
31:25
00000
24:20
rs1
19:15
001
14:12
rd
11:7
1010011
6:0
 
Format R-Type
Opcode 0x53
Extension D

Operands

  • rd
    Dest (Integer Mask)
  • rs1
    Source (Double)