From 73440106c35e9db81ebfded54d4f2f67df0edd57 Mon Sep 17 00:00:00 2001
From: "russell@unturf.com" <russell@unturf.com>
Date: Tue, 14 Apr 2026 15:11:43 -0400
Subject: [PATCH] Add friction.sh benchmark: C is 3-6x faster than Python impl

fib(35):     C 0.1ms vs Python 0.6ms (6x)
fib-rec(20): C 44ms vs Python 283ms (6.4x)
ack(3,4):    C 31ms vs Python 93ms (3x)
sum-to(50k): C 129ms vs Python 515ms (4x)

Both still ~20-30x slower than native CPython (interpreter overhead).
SBCL would be within 2-5x of C with native compilation.
---
 friction.sh | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 friction.sh

diff --git a/friction.sh b/friction.sh
new file mode 100644
index 0000000..b4f9f93
--- /dev/null
+++ b/friction.sh
@@ -0,0 +1,127 @@
+#!/bin/bash
+# friction.sh — Head-to-head benchmark: CPython vs uncommonlisp-Python vs uncommonlisp-C
+#
+# Usage: bash friction.sh
+
+set -e
+cd "$(dirname "$0")"
+
+echo "═══════════════════════════════════════════════════════════════"
+echo "Friction Benchmark: CPython vs uncommonlisp-Python vs uncommonlisp-C"
+echo "═══════════════════════════════════════════════════════════════"
+echo
+
+# Build C version
+make -C c all -s 2>/dev/null
+
+# ── fib(35) iterative ──────────────────────────────────────────
+echo ">>> fib(35) iterative"
+
+printf "  CPython:             "
+python3 -c "
+import time
+def fib(n):
+    a, b = 0, 1
+    for _ in range(n): a, b = b, a+b
+    return a
+t=time.perf_counter(); r=fib(35); print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-Python: "
+python3 -c "
+import time; from uncommonlisp import *
+g=make_global_env(); [leval(e,g) for e in read_all(PRELUDE)]
+[leval(e,g) for e in read_all('(auto-compile! #t)')]
+[leval(e,g) for e in read_all('(define (fib n) (let loop ((a 0) (b 1) (i 0)) (if (= i n) a (loop b (+ a b) (+ i 1)))))')]
+t=time.perf_counter(); r=[leval(e,g) for e in read_all('(fib 35)')][-1]
+print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-C:      "
+/usr/bin/time -f "%e s" ./c/uncommonlisp -e '(define (fib n) (let loop ((a 0) (b 1) (i 0)) (if (= i n) a (loop b (+ a b) (+ i 1))))) (display (fib 35)) (newline)' 2>&1
+
+echo
+
+# ── fib(20) tree-recursive ──────────────────────────────────────
+echo ">>> fib(20) tree-recursive"
+
+printf "  CPython:             "
+python3 -c "
+import time
+def fib(n):
+    if n <= 1: return n
+    return fib(n-1) + fib(n-2)
+t=time.perf_counter(); r=fib(20); print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-Python: "
+python3 -c "
+import time,sys; sys.setrecursionlimit(50000); from uncommonlisp import *
+g=make_global_env(); [leval(e,g) for e in read_all(PRELUDE)]
+[leval(e,g) for e in read_all('(auto-compile! #t)')]
+[leval(e,g) for e in read_all('(define (fib n) (if (<= n 1) n (+ (fib (- n 1)) (fib (- n 2)))))')]
+t=time.perf_counter(); r=[leval(e,g) for e in read_all('(fib 20)')][-1]
+print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-C:      "
+/usr/bin/time -f "%e s" ./c/uncommonlisp -e '(define (fib n) (if (<= n 1) n (+ (fib (- n 1)) (fib (- n 2))))) (display (fib 20)) (newline)' 2>&1
+
+echo
+
+# ── ackermann(3,4) ──────────────────────────────────────────────
+echo ">>> ackermann(3,4)"
+
+printf "  CPython:             "
+python3 -c "
+import time,sys; sys.setrecursionlimit(50000)
+def ack(m,n):
+    if m==0: return n+1
+    if n==0: return ack(m-1,1)
+    return ack(m-1, ack(m, n-1))
+t=time.perf_counter(); r=ack(3,4); print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-Python: "
+python3 -c "
+import time,sys; sys.setrecursionlimit(50000); from uncommonlisp import *
+g=make_global_env(); [leval(e,g) for e in read_all(PRELUDE)]
+[leval(e,g) for e in read_all('(auto-compile! #t)')]
+[leval(e,g) for e in read_all('(define (ack m n) (cond ((= m 0) (+ n 1)) ((= n 0) (ack (- m 1) 1)) (else (ack (- m 1) (ack m (- n 1))))))')]
+t=time.perf_counter(); r=[leval(e,g) for e in read_all('(ack 3 4)')][-1]
+print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-C:      "
+/usr/bin/time -f "%e s" ./c/uncommonlisp -e '(define (ack m n) (cond ((= m 0) (+ n 1)) ((= n 0) (ack (- m 1) 1)) (else (ack (- m 1) (ack m (- n 1)))))) (display (ack 3 4)) (newline)' 2>&1
+
+echo
+
+# ── sum-to(50000) tail-recursive ────────────────────────────────
+echo ">>> sum-to(50000) tail-recursive"
+
+printf "  CPython:             "
+python3 -c "
+import time
+def s(n):
+    acc=0
+    while n>0: acc+=n; n-=1
+    return acc
+t=time.perf_counter(); r=s(50000); print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-Python: "
+python3 -c "
+import time; from uncommonlisp import *
+g=make_global_env(); [leval(e,g) for e in read_all(PRELUDE)]
+[leval(e,g) for e in read_all('(auto-compile! #t)')]
+[leval(e,g) for e in read_all('(define (sum-to n) (let loop ((i n) (acc 0)) (if (= i 0) acc (loop (- i 1) (+ acc i)))))')]
+t=time.perf_counter(); r=[leval(e,g) for e in read_all('(sum-to 50000)')][-1]
+print(f'{(time.perf_counter()-t)*1000:.3f}ms  result={r}')
+"
+
+printf "  uncommonlisp-C:      "
+/usr/bin/time -f "%e s" ./c/uncommonlisp -e '(define (sum-to n) (let loop ((i n) (acc 0)) (if (= i 0) acc (loop (- i 1) (+ acc i))))) (display (sum-to 50000)) (newline)' 2>&1
+
+echo
+echo "═══════════════════════════════════════════════════════════════"