Visual Instruction Set
Encyclopedia
Visual Instruction Set, or VIS, is a SIMD
instruction set for SPARC V9
microprocessor
s developed by Sun Microsystems
. There are three versions of VIS: VIS 1, VIS 2 and VIS 2+. An updated version, VIS 3.0, was planned for implementation on the cancelled Rock processor
.
microprocessor (1995) and by Fujitsu in their SPARC64 GP microprocessors (2000).
VIS 2 was first implemented by the UltraSPARC III
. All subsequent UltraSPARC and SPARC64 microprocessors implement the instruction set.
As with the SIMD instruction set extensions on RISC processors, VIS strictly conform to the main principle of RISC: keep the instruction set concise and efficient.
This design is very different from comparable extensions on CISC
processors, such as MMX, SSE
, SSE2
, SSE3
, SSE4
, 3DNow!
.
Basically, this RISC principle can make the pipelines more simple and efficient and consequently bring better throughput and performance.
However, Intel and AMD can easily add new instruction set extensions to x86/x64 processors while Sun
must be very careful in adding new extensions to SPARC processors, which may be considered an advantage of CISC over RISC.
Sometimes programmers must use several VIS instructions to accomplish an operation that can be done with only one MMX or SSE
instruction, but it should be kept in mind that fewer instructions doesn't automatically result in better performance.
/SSE2
/AltiVec
.
VIS includes a number of operations primarily for graphics support, so most of them are only for integers. These include 3D to 2D conversion, edge processing
and pixel distance.
There are four ways to use VIS in code:
SIMD
Single instruction, multiple data , is a class of parallel computers in Flynn's taxonomy. It describes computers with multiple processing elements that perform the same operation on multiple data simultaneously...
instruction set for SPARC V9
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
s developed by Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
. There are three versions of VIS: VIS 1, VIS 2 and VIS 2+. An updated version, VIS 3.0, was planned for implementation on the cancelled Rock processor
Rock processor
Rock was a multithreading, multicore, SPARC microprocessor developed at Sun Microsystems. Now canceled, it was a separate development from the CoolThreads/Niagara family of processors....
.
History
VIS 1 was introduced in 1994 and was first implemented by Sun in their UltraSPARCUltraSPARC
The UltraSPARC is a microprocessor developed by Sun Microsystems who is now a part of Oracle Corporation and fabricated by Texas Instruments that implements the SPARC V9 instruction set architecture . It was introduced in mid-1995. It was the first microprocessor from Sun Microsystems to implement...
microprocessor (1995) and by Fujitsu in their SPARC64 GP microprocessors (2000).
VIS 2 was first implemented by the UltraSPARC III
UltraSPARC III
The UltraSPARC III, code-named "Cheetah", is a microprocessor that implements the SPARC V9 instruction set architecture developed by Sun Microsystems and fabricated by Texas Instruments. It was introduced in 2001 and operated at 600 to 900 MHz. It was succeeded by the UltraSPARC IV in 2004...
. All subsequent UltraSPARC and SPARC64 microprocessors implement the instruction set.
Differences vs x86
However VIS is not an instruction toolkit like Intel's MMX and SSE. MMX has only 8 registers shared with the FPU stack, while SPARC processors usually have a much larger number of registers (one characteristics of RISC architectures).As with the SIMD instruction set extensions on RISC processors, VIS strictly conform to the main principle of RISC: keep the instruction set concise and efficient.
This design is very different from comparable extensions on CISC
Complex instruction set computer
A complex instruction set computer , is a computer where single instructions can execute several low-level operations and/or are capable of multi-step operations or addressing modes within single instructions...
processors, such as MMX, SSE
Streaming SIMD Extensions
In computing, Streaming SIMD Extensions is a SIMD instruction set extension to the x86 architecture, designed by Intel and introduced in 1999 in their Pentium III series processors as a reply to AMD's 3DNow! . SSE contains 70 new instructions, most of which work on single precision floating point...
, SSE2
SSE2
SSE2, Streaming SIMD Extensions 2, is one of the Intel SIMD processor supplementary instruction sets first introduced by Intel with the initial version of the Pentium 4 in 2001. It extends the earlier SSE instruction set, and is intended to fully supplant MMX. Intel extended SSE2 to create SSE3...
, SSE3
SSE3
SSE3, Streaming SIMD Extensions 3, also known by its Intel code name Prescott New Instructions , is the third iteration of the SSE instruction set for the IA-32 architecture. Intel introduced SSE3 in early 2004 with the Prescott revision of their Pentium 4 CPU...
, SSE4
SSE4
SSE4 is a CPU instruction set used in the Intel Core microarchitecture and AMD K10 . It was announced on 27 September 2006 at the Fall 2006 Intel Developer Forum, with vague details in a white paper; more precise details of 47 instructions became available at the Spring 2007 Intel Developer Forum...
, 3DNow!
3DNow!
3DNow! is an extension to the x86 instruction set developed by Advanced Micro Devices . It adds single instruction multiple data instructions to the base x86 instruction set, enabling it to perform simple vector processing, which improves the performance of many graphic-intensive applications...
.
Basically, this RISC principle can make the pipelines more simple and efficient and consequently bring better throughput and performance.
However, Intel and AMD can easily add new instruction set extensions to x86/x64 processors while Sun
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
must be very careful in adding new extensions to SPARC processors, which may be considered an advantage of CISC over RISC.
Sometimes programmers must use several VIS instructions to accomplish an operation that can be done with only one MMX or SSE
Streaming SIMD Extensions
In computing, Streaming SIMD Extensions is a SIMD instruction set extension to the x86 architecture, designed by Intel and introduced in 1999 in their Pentium III series processors as a reply to AMD's 3DNow! . SSE contains 70 new instructions, most of which work on single precision floating point...
instruction, but it should be kept in mind that fewer instructions doesn't automatically result in better performance.
Functionality
VIS re-uses existing SPARC V9 64-bit floating point registers to hold multiple 8, 16, or 32-bit integer values. In this respect VIS is more similar to the design of MMX than other SIMD architectures such as SSEStreaming SIMD Extensions
In computing, Streaming SIMD Extensions is a SIMD instruction set extension to the x86 architecture, designed by Intel and introduced in 1999 in their Pentium III series processors as a reply to AMD's 3DNow! . SSE contains 70 new instructions, most of which work on single precision floating point...
/SSE2
SSE2
SSE2, Streaming SIMD Extensions 2, is one of the Intel SIMD processor supplementary instruction sets first introduced by Intel with the initial version of the Pentium 4 in 2001. It extends the earlier SSE instruction set, and is intended to fully supplant MMX. Intel extended SSE2 to create SSE3...
/AltiVec
AltiVec
AltiVec is a floating point and integer SIMD instruction set designed and owned by Apple, IBM and Freescale Semiconductor, formerly the Semiconductor Products Sector of Motorola, , and implemented on versions of the PowerPC including Motorola's G4, IBM's G5 and POWER6 processors, and P.A. Semi's...
.
VIS includes a number of operations primarily for graphics support, so most of them are only for integers. These include 3D to 2D conversion, edge processing
Edge detection
Edge detection is a fundamental tool in image processing and computer vision, particularly in the areas of feature detection and feature extraction, which aim at identifying points in a digital image at which the image brightness changes sharply or, more formally, has discontinuities...
and pixel distance.
There are four ways to use VIS in code:
- The GCCGNU Compiler CollectionThe GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain...
-mvis option - Use inline assembly
- Use inline template in VSDK, similar to compiler intrinsics, which have C function like interfaces
- Use the mediaLibMediaLibmediaLib is a portable low level library for accelerating multimedia applications, with interfaces in C. It is developed by Sun Microsystems and open sourced under the CDDL license as part of the OpenSolaris project...
multimedia library, which has C function interfaces. It uses VIS on SPARC platforms (and MMX/SSE/SSE2 on x86/x64 platforms) to accelerate multimedia application execution