backend: emit bitwise ops as native ops (test.check PRNG ~2.4x)

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Profiling the test.check distribution/large-sample slowness (jolt-i5if): the
hot path is the SplitMix PRNG, dominated by 64-bit mix arithmetic, and the
bitwise ops (bit-and/or/xor/not, shifts) were NOT in the backend native-ops
table — so (bit-xor a b) compiled to a var-deref through the variadic overlay
(__bit-xor) instead of a direct call, the way +/-/* already emit.

Map bit-and/or/xor/not to the Chez bitwise-and/ior/xor/not primitives (inlined
to native code; a non-integer operand now errors like the JVM instead of being
silently truncated) and the shifts to a direct helper call. bit-and-not stays on
its overlay — its only Scheme impl is 2-arg, so a value-position arity-3 use
would mis-emit.

mix-64 arithmetic 2.7x faster, raw split+rand-long 2.4x, gen/vector ~1.4x. The
remaining gap is the bignum-vs-native-long floor (~20x, substrate) plus the
generator machinery (deftype/fn dispatch, separate). Corpus rows added for value
position, bit-not, apply, and a full-64-bit unsigned shift.

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Yogthos 2026-06-28 11:25:52 -04:00

parent b5ea06c5c2

commit f17b68ccfe

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