Commit: d34260f8d53fb00903e33949e55629456f7eaf16 - rpypkgs (git)

Nix flake for RPython interpreters

Commit MetaInfo

• Revision: d34260f8d53fb00903e33949e55629456f7eaf16 (tree)
• Time: 2024-04-09 05:53:34
• Author: Corbin <cds@corb...>
• Commiter: Corbin

Log Message

Add JIT to DIVSPL interpreter.

I only saw a minor speedup in my testing, but the assembly code is
well-structured and should do a decent job for small numbers of rules.
The number of failed guards is exponential in the number of rules, so
I'm not sure if there's any good solution.

Change Summary

• modified: divspl/divspl.py
• modified: flake.nix

Incremental Difference

--- a/divspl/divspl.py
+++ b/divspl/divspl.py
@@ -1,9 +1,12 @@
 import sys
 
+from rpython.jit.codewriter.policy import JitPolicy
+from rpython.rlib.jit import JitDriver
+
 # This is a basic interpreter for DIVSPL, as described at
 # https://www.promptworks.com/blog/the-fastest-fizzbuzz-in-the-west
 # Version 0: Initial functionality
-# Version 1: Port to RPython
+# Version 1: Port to RPython, add JIT
 
 def parseAssignment(line):
     word, number = [w.strip() for w in line.rsplit("=", 1)]
@@ -12,13 +15,22 @@ def parseAssignment(line):
 def parse(lines):
     # The first line must be the range.
     start, stop = [int(n.strip()) for n in lines[0].split("...")]
-    assignments = [parseAssignment(line) for line in lines[1:]]
+    # Skip empty lines, usually at EOF.
+    assignments = [parseAssignment(line) for line in lines[1:] if line]
     return start, stop, assignments
 
+def location(stop, assignments):
+    return "%d rules, stop at %d" % (len(assignments), stop)
+driver = JitDriver(greens=["stop", "assignments"], reds=["i"],
+                   get_printable_location=location)
+
 def run(start, stop, assignments):
-    for i in range(start, stop + 1):
+    i = start
+    while i <= stop:
+        driver.jit_merge_point(stop=stop, assignments=assignments, i=i)
         s = [w for w, n in assignments if not i % n]
         print ("".join(s) if s else str(i))
+        i += 1
 
 # NB: programs should already be split into lines
 def main(argv):
@@ -31,6 +43,6 @@ def main(argv):
     return 0
 
 def target(*args): return main, None
+def jitpolicy(driver): return JitPolicy()
 
-if __name__ == "__main__":
-    sys.exit(main(sys.argv))
+if __name__ == "__main__": sys.exit(main(sys.argv))

--- a/flake.nix
+++ b/flake.nix
@@ -131,7 +131,6 @@
           entrypoint = "divspl.py";
           binName = "divspl-c";
           binInstallName = "divspl";
-          optLevel = "2";
         } {
           pname = "divspl";
           version = "1";