Encoding:

Format:

LD.df 

LD.B wd,s10(rs)

LD.H wd,s10(rs)

LD.W wd,s10(rs)

LD.D wd,s10(rs)

Purpose:

Vector Load

Vector load element-by-element from base register plus offset memory address,

Description:

wd[i] = memory[rs + (s10 + i) * sizeof(wd[i])]

The WRLEN / 8 bytes at the ef fective memory location addressed by the basers and the 10-bit signed immediate offset s10 are fetched and placed in wd as elements of data format df.

The s10 offset in data format df units is added to the base rs to form the effective memory location address. rs and the effective memory location address have no alignment restrictions.

If the effective memory location address is element aligned, the vector load instruction is atomic at the element level with no guaranteed ordering among elemen ts, i.e. each element load is an ato mic operation issued in no particular order with respect to the element's vector position.

By convention, in the assembly language syntax all offsets are in bytes and have to be multiple of the size of the data format df. The assembler determines the s10 bitfield value dividing the byte offset by the size of the data format df.

Restrictions:

Address-dependent exceptions are possible.

Operation:

LD.B
   a = rs + s10
   LoadByteVector(WR[wd]WRLEN-1..0, a, WRLEN/8)
LD.H
   a = rs + s10 * 2
   LoadHalfwordVector(WR[wd]WRLEN-1..0, a, WRLEN/16)
LD.W
   a = rs + s10 * 4
   LoadWordVector(WR[wd]WRLEN-1..0, a, WRLEN/32)
LD.D
   a = rs + s10 * 8
   LoadDoublewordVector(WR[wd]WRLEN-1..0, a, WRLEN/64)
function LoadByteVector(ts, a, n)
   /* Implementation defined load ts vector of n bytes from virtual
         address a. */
endfunction LoadByteVector
function LoadHalfwordVector(ts, a, n)
   /* Implementation defined load ts vector of n halfwords from
          virtual address a. */
endfunction LoadHalfwordVector
function LoadWordVector(ts, a, n)
   /* Implementation defined load ts vector of n words from virtual
         address a. */
endfunction LoadWordVector
function LoadDoublewordVector(ts, a, n)
   /* Implementation defined load ts vector of n doublewords from
         virtual address a. */
endfunction LoadDoublewordVector

Exceptions:

Reserved Instruction Exception, MSA Disabled Exception. Data access TLB and Address Error Exceptions.