Brummel
c897d2eef0
Closes the question CLAUDE.md has carried since day one ("LLVM-
linkable, performance is extremely important") with data. Hand-C
variants of the four bench fixtures, compiled with clang -O2,
each carefully matching the AILang algorithm and explicitly
documenting representation differences (cell width, leak policy)
that affect the ratio.
Three substantive findings:
1. Pure-compute parity with C: bench_compute_collatz runs at
AILang/C = 0.99x across both allocators. AILang's IR composes
with LLVM's optimizer at the same level a hand-C source does.
This is the LLVM-linkable performance claim, backed by data
for the first time. bench_compute_intsum (1.05-1.18x) confirms.
2. AILang bump beats glibc malloc 2x on linear allocation:
bench_list_sum.bump/c = 0.50x. Bump's two-instruction inline
fastpath outperforms glibc's free-list-managed malloc on
no-free workloads. Quantitatively measured for the first time.
3. RC overhead vs C malloc quantified: bench_list_sum.rc/c =
1.49x, bench_tree_walk.rc/c = 2.61x. The 8-byte refcount
header + zero-init + libc backing add 50-160% over glibc
malloc on these implicit-mode workloads. Explicit-mode + a
free()-adding C variant (21'f, queued) will close the
apples-to-apples gap on dec-cost.
CLAUDE.md updated to list bench/cross_lang.py as the third
tidy-iter gate alongside bench/check.py and bench/compile_check.py.
20 new metrics in bench/baseline_cross_lang.json with 12-15%
tolerances (cross-language ratios are inherently noisier than
within-AILang ratios — two compiler stacks contribute variance).
40 lines
1023 B
C
40 lines
1023 B
C
// Hand-C reference for bench_compute_intsum.
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//
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// Same algorithm as examples/bench_compute_intsum.ailx — accumulate
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// `i * 7` for i in [n, n-1, ..., 1], printing the final acc.
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// Three sizes: 1M / 10M / 50M iterations.
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//
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// Just like AILang's version under -O2, this loop is closed-form
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// reducible (sum_{i=1..N} i*7 = 7*N*(N+1)/2). clang -O2 will likely
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// fold it. The AILang/C wall-time ratio at this fixture answers
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// "does AILang's IR enable the same constant fold C's source does"
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// — both should be startup-dominated.
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//
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// Build: clang -O2 -o compute_intsum compute_intsum.c
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// Expected stdout (one int per line):
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// 3500003500000
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// 350000035000000
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// 8750000175000000
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#include <stdio.h>
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static long intsum_loop(long n) {
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long acc = 0;
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while (n > 0) {
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acc += n * 7;
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n -= 1;
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}
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return acc;
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}
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static void run_one(long n) {
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printf("%ld\n", intsum_loop(n));
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}
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int main(void) {
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run_one(1000000);
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run_one(10000000);
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run_one(50000000);
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return 0;
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}
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