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Home > ARMv6 SIMD Instruction Intrinsics > __sxtab16 intrinsic |
This intrinsic inserts an SXTAB16
instruction into the instruction stream generated by the compiler.
It enables you to extract two 8-bit values from the second operand (at bit positions [7:0] and [23:16]), sign-extend them to 16-bits each, and add the results to the first operand.
unsigned int __sxtab16(unsigned int
val1
, unsigned int val2
)
Where:
val1
holds the values that the extracted and sign-extended values are added to
val2
holds the two 8-bit values to be extracted and sign-extended.
The __sxtab16
intrinsic returns the addition
of val1
and val2
,
where the 8-bit values in val2
[7:0] and val2
[23:16]
have been extracted and sign-extended prior to the addition.
unsigned int extract_sign_extend_and_add(unsigned int val1, unsigned int val2) { unsigned int res; res = __sxtab16(val1,val2); /* res[15:0] = val1[15:0] + SignExtended(val2[7:0]) res[31:16] = val1[31:16] + SignExtended(val2[23:16]) */ return res; }