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A comment on The Burroughs B5000 - 20 Years Later and Still Ahead of the Times?. Parent comment

Re:The Burroughs B5000 - 20 Years Later and Still Ahead of t... by ScottBurson on Tuesday May 22, 2012 @09:54PM (#4011107)
I'll hazard a guess as to what's going on here. The OP mentions the B5000's use of descriptors. I think it's decoding a descriptor and doing bounds checking on every array access. That would certainly slow down a machine that didn't have hardware support for these operations.
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Re:The Burroughs B5000 - 20 Years Later and Still Ahead of t... by tedunangst on Tuesday May 22, 2012 @10:54PM (#4011286)
That's a fairly trivial optimization for a jit to perform. And a 1000x penalty for bounds checking? No way, that would literally require your bounds check to take a minimum of 1000 instructions, even assuming your inner loop didn't do anything meaningful with the accessed value.
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