The Multimedia Acceleration eXtensions or MAX are instruction set extensions to the Hewlett-Packard PA-RISC instruction set architecture (ISA). It was developed to improve the performance of multimedia applications that were becoming more prevalent during the 1990s. MAX instructions operate on 32- or 64-bit SIMD data types consisting of multiple 16-bit integers packed in general purpose registers. The available functionality includes additions, subtractions and shifts. The first version, MAX-1, was for the 32-bit PA-RISC 1.1 ISA. MAX-1 was first implemented with the PA-7100LC in 1994. It is usually attributed as being the first SIMD extensions to an ISA. The second version, MAX-2, was for the 64-bit PA-RISC 2.0 ISA. It was first implemented in the PA-8000 microprocessor released in 1996.
MAX-1
| Instruction |
Description |
| HADD |
Parallel add with modulo arithmetic |
| HADD,ss |
Parallel add with signed saturation |
| HADD,us |
Parallel add with unsigned saturation |
| HSUB |
Parallel subtract with modulo arithmetic |
| HSUB,ss |
Parallel subtract with signed saturation |
| HSUB,us |
Parallel subtract with unsigned saturation |
| HAVE |
Parallel average |
| HSHLADD |
Parallel shift left and add with signed saturation |
| HSHRADD |
Parallel shift right and add with signed saturation |
MAX-2
MAX-2 instructions operate on multiple integers in 64-bit quantities. All have a one cycle latency in the PA-8000 microprocessor and its derivatives.
| Instruction |
Description |
| HADD |
Parallel add with modulo arithmetic |
| HADD,ss |
Parallel add with signed saturation |
| HADD,us |
Parallel add with unsigned saturation |
| HSUB |
Parallel subtract with modulo arithmetic |
| HSUB,ss |
Parallel subtract with signed saturation |
| HSUB,us |
Parallel subtract with unsigned saturation |
| HSLADD |
Parallel shift left and add with signed saturation |
| HSHRADD |
Parallel shift right and add with signed saturation |
| HAVG |
Parallel average |
| HSHR |
Parallel shift right signed |
| HSHR,u |
Parallel shift right unsigned |
| HSHL |
Parallel shift left |
| MIXH |
Mix |
| MIXW |
Mix |
| PERMH |
Permute |
References
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