Intel i86W Manual page 192

PROGRAMMING EXAMPLES
Table 9-3. Accumulator Initialization Table
Table Values
Alignment
*mZ *mR *mG *mB
0
-1, -3
-1, -2,
-3,
2 -2, -4 -2 -3, -4,
4
-3,
-5 -3, -4,
-5,
6 -4, -6 -4, -5, -6,
II ACCUMULATOR INITIALIZATION TABLE
.data; .align .double
acc_init_tab:: .double [16] 0
.dsect
-4
-1,
-2,
-5 -2, -3,
-6 -3,
-4,
-7 -4, -5,
aBi: .double
aGi: . double
aRi: . double
aZi: .double
II Four initial 16-bit blue values
II Four initial 16-bit green values
II Four initial 16-bit red values
II Two initial 32-bit Z values
.end
.text
II INITIALIZE ACCUMULATORS
·macro acc_init Lalign, Rtab, Rx, Ry, Fx, Fxh
-3,
-4,
-5,
-6,
II Lalign -- left-end alignment C0 .. 3) in two-byte units
II
Rtab -- register to use for addressing the table
II Rx, Ry, Fx, Fxh -- scratch registers
mov acc_init_tab, Rtab II
-4
-5
-6
-7
shl 5, Lalign, Lalign
II Multiply by row width
-1, -2, -3,
-2, -3, -4,
-3, -4, -5,
-4, -5, -6
adds Lalign, Rtab, Rtab II Index row corresponding to alignment
fld·d aZiCRtab), aZ
II Z
ixfr Zl, Fx II Z
fld.d aRiCRtab), aR
II R--Load constant values
shl 16, Redl, Rx II R--Shift startingvalue to hi-order
fmov.ss Fx, Fxh II Z
shr 16, Rx, Ry II R--Redl stripped of sign bits
fiadd.dd Fx, aZ, aZ
II Z
or Rx, Ry, Ry II R--Form CRedl,Redl)
ixfr Ry, Fx
II R--Put in 64-bit register
fld.d aGiCRtab), aG II G
shl 16, Grnl, Rx
II G
fmov.ss Fx, Fxh II R--Form CRedl,Redl,Redl,Redl)
shr 16, Rx, Ry
II G
fiadd.dd Fx, aR, aR
II R--Add variables to constants
or Rx, Ry, Ry
I I
G
ixfr Ry, Fx
II G
fld.d aBiCRtab), aB
II
B
shl 16, Blul, Rx
II B
fmov.ss Fx, Fxh
II
G
shr 16, Rx, Ry
I I
B
fiadd.dd Fx, aG, aG
II G
or Rx, Ry, Ry
II
B
ixfr Ry, Fx
II
B
fmov.ss Fx, Fxh II B
fiadd.dd Fx, aB, aB
II
B
.endm
Example 9-20. Accumulator Initialization
9-30
-4
-5
-6
-7