Sun Microsystems UltraSPARC-I User Manual page 234

13.5.8 Edge Handling Instructions
opcode
EDGE8
EDGE8L
EDGE16
EDGE16L
EDGE32
EDGE32L
Format (3):
10 rd
31 30 29
Suggested Assembly Language Syntax
edge8
edge8l
edge16
edge16l
edge32
edge32l
Description:
These instructions are used to handle the boundary conditions for parallel pixel
scan line loops, where src1 is the address of the next pixel to render and src2 is
the address of the last pixel in the scan line.
EDGE8L, EDGE16L, and EDGE32L are little-endian versions of EDGE8, EDGE16
and EDGE32. They produce an edge mask that is bit reversed from their big-en-
dian counterparts, but are otherwise the same. This makes the mask consistent
with the mask generated by the graphics compare operations (see Section 13.5.7,
"Pixel Compare Instructions," on page 217) on little-endian data.
A 2- (EDGE32), 4- (EDGE16), or 8-bit (EDGE8) pixel mask is stored in the least
significant bits of rd. The mask is computed from left and right edge masks as fol-
lows:
1. The left edge mask is computed from the 3 least significant bits (LSBs) of
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rs1 and the right edge mask is computed from the 3 LSBs of rs2, according
opf
0 0000 0000
Eight 8-bit edge boundary processing
0 0000 0010
Eight 8-bit edge boundary processing, little-
endian
0 0000 0100
Four 16-bit edge boundary processing
0 0000 0110
Four 16-bit edge boundary processing, little-
endian
0 0000 1000
Four 32-bit edge boundary processing
0 0000 1010
Two 32-bit edge boundary processing, little-
endian
11 0110
25 24 19 18
reg , reg , reg
rs1 rs2 rd
reg , reg , reg
rs1 rs2 rd
reg , reg , reg
rs1 rs2 rd
reg , reg , reg
rs1 rs2 rd
reg , reg , reg
rs1 rs2 rd
reg , reg , reg
rs1 rs2 rd
13. UltraSPARC Extended Instructions
operation
rs1 opf
14 13
rs2
5 4 0