21 lines
716 B
Plaintext
21 lines
716 B
Plaintext
;;;; A hot loop that does nothing but index a bounds-checked array.
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;;;;
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;;;; The suspected cost is three frame temporaries per check. This one has an
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;;;; A/B that the others do not: --no-bounds-checks builds the same program
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;;;; with the check gone, on both sides, so the difference between the two
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;;;; x86 numbers is the check and nothing else, and the same difference on
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;;;; the LLVM side says what the check costs when a compiler is allowed to
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;;;; hoist it out of the loop.
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(defvar xs [1024 i32])
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(defn main [] i32
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(dotimes [i 1024]
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(set (at xs i) i))
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(let [acc (i64 0)]
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(dotimes [r 20000]
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(dotimes [i 1024]
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(set acc (+ acc (i64 (at xs i))))))
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(print acc) (println ""))
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0)
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