OE
March 30, 2004, 07:38 PM
This is an interesting turn of events.
Intel says its new 64-bit x86 extensions will run the same 64-bit operating systems and almost all the same 64-bit application software as AMD’s 64-bit architecture. AMD says software compatibility should be no surprise, because Intel virtually reverse-engineered its 64-bit extensions from AMD64. An independent analysis by Microprocessor Report indicates both companies are correct. Except for a few minor differences, the two 64-bit architectures are identical.
MPR compared all the new instructions, modified instructions, deleted instructions, and modifications to the register files—including control registers, system registers, and registers visible to application programs. We also compared the memory-addressing schemes and many other architectural features, such as data-addressing modes, context-switching behavior, interrupt handling, and support for existing 16- and 32-bit x86 execution modes. In every case, we found Intel had patterned its 64-bit x86 architecture after AMD64 in almost every detail.
However, we also found a few differences that could make some software written for one 64-bit architecture incompatible with the other architecture. Some of these differences may be resolved in future 64-bit x86 processors, or even in future steppings of x86 processors already announced or on the market. In other cases, software can easily adapt to the differences by executing slightly different code, after first probing the CPU to learn which 64-bit extensions it supports.
MPR found nothing to contradict Intel’s promise that its 64-bit x86 processors will run the 64-bit operating systems developed for AMD64. At the same time, Intel’s reluctance to make a blanket guarantee about mutual 64-bit software compatibility is justified by the minor differences we discovered. Of course, that’s always the case when Intel or AMD introduces new x86 extensions—such as Intel’s SSE3 media extensions, which aren’t yet supported by AMD.
Despite the differences, Intel clearly derived its 64-bit architecture by reading AMD’s prerelease documentation for AMD64 and by testing AMD64 processors. Intel’s reverse-engineering of AMD64 marks a major turning point in the historical relationship between the companies. Although AMD has in the past introduced some innovations to the x86 architecture—the 3DNow multimedia extensions being a prime example—this is the first time AMD has truly steered the direction of the world’s most important microprocessor architecture, which Intel invented in 1978 and has closely guarded for 26 years.
http://www.mdronline.com/watch/watch_abstract.asp?Volname=Issue%20%23118&SID=1137 &on=T&SourceID=00000377000000000000
Intel says its new 64-bit x86 extensions will run the same 64-bit operating systems and almost all the same 64-bit application software as AMD’s 64-bit architecture. AMD says software compatibility should be no surprise, because Intel virtually reverse-engineered its 64-bit extensions from AMD64. An independent analysis by Microprocessor Report indicates both companies are correct. Except for a few minor differences, the two 64-bit architectures are identical.
MPR compared all the new instructions, modified instructions, deleted instructions, and modifications to the register files—including control registers, system registers, and registers visible to application programs. We also compared the memory-addressing schemes and many other architectural features, such as data-addressing modes, context-switching behavior, interrupt handling, and support for existing 16- and 32-bit x86 execution modes. In every case, we found Intel had patterned its 64-bit x86 architecture after AMD64 in almost every detail.
However, we also found a few differences that could make some software written for one 64-bit architecture incompatible with the other architecture. Some of these differences may be resolved in future 64-bit x86 processors, or even in future steppings of x86 processors already announced or on the market. In other cases, software can easily adapt to the differences by executing slightly different code, after first probing the CPU to learn which 64-bit extensions it supports.
MPR found nothing to contradict Intel’s promise that its 64-bit x86 processors will run the 64-bit operating systems developed for AMD64. At the same time, Intel’s reluctance to make a blanket guarantee about mutual 64-bit software compatibility is justified by the minor differences we discovered. Of course, that’s always the case when Intel or AMD introduces new x86 extensions—such as Intel’s SSE3 media extensions, which aren’t yet supported by AMD.
Despite the differences, Intel clearly derived its 64-bit architecture by reading AMD’s prerelease documentation for AMD64 and by testing AMD64 processors. Intel’s reverse-engineering of AMD64 marks a major turning point in the historical relationship between the companies. Although AMD has in the past introduced some innovations to the x86 architecture—the 3DNow multimedia extensions being a prime example—this is the first time AMD has truly steered the direction of the world’s most important microprocessor architecture, which Intel invented in 1978 and has closely guarded for 26 years.
http://www.mdronline.com/watch/watch_abstract.asp?Volname=Issue%20%23118&SID=1137 &on=T&SourceID=00000377000000000000