Encoding:

Format:

FLOG2.df 

FLOG2.W wd,ws

FLOG2.D wd,ws

Purpose:

Vector Floating-Point Base 2 Logarithm

Vector floating-point base 2 logarithm.

Description:

wd[i] = log2(ws[i])

The signed integral base 2 e xponents of floating-point elements in vector ws are written as floating-point values to vector elements wd.

This operation is the homogeneous base 2 logB() as defined by the IEEE Standard for Floating-Point Arithmetic

754^TM-2008.

The ws operands and wd results are values in floating-point data format df.

Restrictions:

Data-dependent exceptions are poss ible as s pecified by the I EEE Standard for Floating-Point Arithmetic 754^TM2008.

Operation:

FLOG2.W
   for i in 0 .. WRLEN/32-1
      l = Log2FP(WR[ws]32i+31..32i, 32)
      WR[wd]32i+31..32i = l
   endfor
FLOG2.D
   for i in 0 .. WRLEN/64-1
      f = Log2FP(WR[ws]64i+63..64i, 64)
      WR[wd]64i+63..64i = f
   endfor
function Log2FP(tt, n)
   /* Implementation defined logarithm base 2 operation. */
endfunction Log2FP

Exceptions:

Reserved Instruction Exception, MSA Disabled Exception, MSA Floating Point Exception.