Assembly code snippets
Details
| Title | Inline MMX Constants |
|---|---|
| Author | bitRAKE |
| Submitted by: | bitRAKE |
| Date added: | 2002-02-24 03:40:33 |
| Date modified: | 2002-02-24 03:40:33 |
Comments
This macro creates global labels for the MMX constants and uses them apon repeated access to the same constant values. The MMX constants are also stored in their own sub-segment of the CONST segment.
Snippet
mxc MACRO val:REQ
LOCAL w,y,z
z SIZESTR <&val>
;; Attempt to compact data
WHILE (z LT 17) AND (z GT 2)
z = z/2
IFDIF @SubStr(<&val>,1,z),@SubStr(<&val>,1+z,z)
z = z + z + 16
ENDIF
ENDM
IF z GT 16
z = z - 16
ENDIF
w TEXTEQU @SubStr(<&val>,1,z)
;; figure out global name for constant
y CATSTR <__MMX_>,w
IF (OPATTR(y)) EQ 0 ;; not defined
CONST$mmx SEGMENT
y LABEL QWORD
w CATSTR <0>,w,<h>
IF z EQ 16
dq w
ELSEIF z EQ 8
dd w,w
ELSEIF z EQ 4
dw w,w,w,w
ELSEIF z EQ 2
db w,w,w,w,w,w,w,w
ENDIF
CONST$mmx ENDS
ENDIF
EXITM y
ENDM
...and you would use it like this:
movq mm7,mxc(<01>) ; eight bytes
movq mm7,mxc(<0101>) ; four words, but same data
movq mm7,mxc(<01234567>) ; two dwords
LOCAL w,y,z
z SIZESTR <&val>
;; Attempt to compact data
WHILE (z LT 17) AND (z GT 2)
z = z/2
IFDIF @SubStr(<&val>,1,z),@SubStr(<&val>,1+z,z)
z = z + z + 16
ENDIF
ENDM
IF z GT 16
z = z - 16
ENDIF
w TEXTEQU @SubStr(<&val>,1,z)
;; figure out global name for constant
y CATSTR <__MMX_>,w
IF (OPATTR(y)) EQ 0 ;; not defined
CONST$mmx SEGMENT
y LABEL QWORD
w CATSTR <0>,w,<h>
IF z EQ 16
dq w
ELSEIF z EQ 8
dd w,w
ELSEIF z EQ 4
dw w,w,w,w
ELSEIF z EQ 2
db w,w,w,w,w,w,w,w
ENDIF
CONST$mmx ENDS
ENDIF
EXITM y
ENDM
...and you would use it like this:
movq mm7,mxc(<01>) ; eight bytes
movq mm7,mxc(<0101>) ; four words, but same data
movq mm7,mxc(<01234567>) ; two dwords