Efficient hardware instructions for single instruction multiple data processors: fast fixed-length value compression

A method for producing a vector of variable-length values from a vector of fixed-length values;

• wherein a first register stores a plurality of fixed-length values from the vector of fixed-length values, wherein each fixed-length value in the vector of fixed-length values is a variable-length value that has been padded, as needed, to achieve a particular fixed length,
• wherein a series of single instruction multiple data (SIMD) subregisters of a second register stores a plurality of length values from a vector of lengths, wherein each fixed-length value in the vector of fixed-length values corresponds to a length value in the vector of lengths, and wherein each length value in the vector of lengths indicates an unpadded length of a corresponding fixed-length value in the vector of fixed-length values;
• the method comprising:
• storing, in a third register, the plurality of fixed-length values into the vector of variable-length values, wherein storing the vector of variable-length values in the third register is based on the vector of lengths, wherein each variable-length value in the vector of variable-length values is unpadded, and wherein a pointer specifies a memory address of the vector of variable length values stored in the third register;
• determining, based on the vector of lengths, a particular key in an offset lookup table;
• determining that a particular offset is indexed in the offset lookup table by the particular key;
• updating the pointer based on the particular offset.

One or more non-transitory, computer-readable media storing one or more instructions that, when executed by one or more processors, cause producing a vector of variable-length values from a vector of fixed-length values;

• wherein a first register stores a plurality of fixed-length values from the vector of fixed-length values, wherein each fixed-length value in the vector of fixed-length values is a variable-length value that has been padded, as needed, to achieve a particular fixed length,
• wherein a series of single instruction multiple data (SIMD) subregisters of a second register stores a plurality of length values from a vector of lengths, wherein each fixed-length value in the vector of fixed-length values corresponds to a length value in the vector of lengths, and wherein each length value in the vector of lengths indicates an unpadded length of a corresponding fixed-length value in the vector of fixed-length values;
• wherein a scatter-mask lookup table stores a plurality of scatter-masks;
• wherein the one or more instructions, when executed by the one or more processors, cause:
• determining, based on the vector of lengths, a particular key in the scatter-mask lookup table;
• determining that the particular key indexes a particular scatter-mask;
• storing, in a third register and based on the particular scatter-mask, the plurality of fixed-length values into the vector of variable-length values, wherein each variable-length value in the vector of variable-length values is unpadded.

A method for producing a vector of variable-length values from a vector of fixed-length values;

• wherein a first register stores a plurality of fixed-length values from the vector of fixed-length values, wherein each fixed-length value in the vector of fixed-length values is a variable-length value that has been padded, as needed, to achieve a particular fixed length,
• wherein a series of single instruction multiple data (SIMD) subregisters of a second register stores a plurality of length values from a vector of lengths, wherein each fixed-length value in the vector of fixed-length values corresponds to a length value in the vector of lengths, and wherein each length value in the vector of lengths indicates an unpadded length of a corresponding fixed-length value in the vector of fixed-length values;
• wherein a scatter-mask lookup table stores a plurality of scatter-masks;
• the method comprising:
• determining, based on the vector of lengths, a particular key in the scatter-mask lookup table;
• determining that the particular key indexes a particular scatter-mask;
• storing, in a third register and based on the particular scatter-mask, the plurality of fixed-length values into the vector of variable-length values, wherein each variable-length value in the vector of variable-length values is unpadded.

One or more non-transitory, computer-readable media storing one or more instructions that, when executed by one or more processors, cause producing a vector of variable-length values from a vector of fixed-length values;

• wherein a first register stores a plurality of fixed-length values from the vector of fixed-length values, wherein each fixed-length value in the vector of fixed-length values is a variable-length value that has been padded, as needed, to achieve a particular fixed length,
• wherein a series of single instruction multiple data (SIMD) subregisters of a second register stores a plurality of length values from a vector of lengths, wherein each fixed-length value in the vector of fixed-length values corresponds to a length value in the vector of lengths, and wherein each length value in the vector of lengths indicates an unpadded length of a corresponding fixed-length value in the vector of fixed-length values;
• wherein a shuffle-mask lookup table stores a plurality of shuffle-masks;
• wherein the one or more instructions, when executed by the one or more processors, cause:
• determining, based on the vector of lengths, a particular key in the shuffle-mask lookup table;
• determining that the particular key indexes a particular shuffle-mask;
• storing, in a third register and based on the particular shuffle-mask, the plurality of fixed-length values into the vector of variable-length values, wherein each variable-length value in the vector of variable-length values is unpadded.

A method for producing a vector of variable-length values from a vector of fixed-length values;

• wherein a first register stores a plurality of fixed-length values from the vector of fixed-length values, wherein each fixed-length value in the vector of fixed-length values is a variable-length value that has been padded, as needed, to achieve a particular fixed length,
• wherein a series of single instruction multiple data (SIMD) subregisters of a second register stores a plurality of length values from a vector of lengths, wherein each fixed-length value in the vector of fixed-length values corresponds to a length value in the vector of lengths, and wherein each length value in the vector of lengths indicates an unpadded length of a corresponding fixed-length value in the vector of fixed-length values;
• wherein a shuffle-mask lookup table stores a plurality of shuffle-masks;
• the method comprising:
• determining, based on the vector of lengths, a particular key in the shuffle-mask lookup table;
• determining that the particular key indexes a particular shuffle-mask;
• storing, in a third register and based on the particular shuffle-mask, the plurality of fixed-length values into the vector of variable-length values, wherein each variable-length value in the vector of variable-length values is unpadded.