From 0dd497895a93bec09c911154ffefab85a9559375 Mon Sep 17 00:00:00 2001
From: Nat Lasseter <Nat Lasseter nathan@bytemark.co.uk>
Date: Sat, 23 Dec 2017 12:53:06 +0000
Subject: C attempt. Probably slightly faster. No free optimisations.

---
 day23/part2    | 39 +++++++++---------------------------
 day23/part2gen | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 day23/part2rb  | 34 +++++++++++++++++++++++++++++++
 3 files changed, 106 insertions(+), 30 deletions(-)
 create mode 100755 day23/part2gen
 create mode 100755 day23/part2rb

(limited to 'day23')

diff --git a/day23/part2 b/day23/part2
index b00d666..634d447 100755
--- a/day23/part2
+++ b/day23/part2
@@ -1,34 +1,13 @@
-#!/usr/bin/env ruby
+#!/bin/bash
 
-def valof(reg_file, reg_or_int)
-  if reg_or_int >= 'a' && reg_or_int <= 'z' then
-    return reg_file[reg_or_int] || 0
-  end
-  return reg_or_int.to_i
-end
+if [[ $(basename $(pwd)) != 'day23' ]] ; then
+  cd day23
+fi
 
-input = $stdin.readlines.map(&:chomp)
+file=$(mktemp --tmpdir=. --suffix=.c)
 
-reg = {'a' => 1}
-pc = 0
+trap "rm $file a.out" EXIT
 
-loop do
-  break if pc < 0 || pc >= input.length
-  istr = input[pc].split
-  case istr[0]
-  when 'set'
-    reg[istr[1]] = valof(reg, istr[2])
-  when 'sub'
-    reg[istr[1]] = valof(reg, istr[1]) - valof(reg, istr[2])
-  when 'mul'
-    reg[istr[1]] = valof(reg, istr[1]) * valof(reg, istr[2])
-  when 'jnz'
-    if valof(reg, istr[1]) != 0 then
-      pc += valof(reg, istr[2])
-      pc -= 1
-    end
-  end
-  pc += 1
-end
-
-puts reg['h']
+./part2gen > $file
+gcc -O3 $file
+./a.out
diff --git a/day23/part2gen b/day23/part2gen
new file mode 100755
index 0000000..2cdcdf6
--- /dev/null
+++ b/day23/part2gen
@@ -0,0 +1,63 @@
+#!/usr/bin/env ruby
+
+def gen_label(here, there)
+  return "label_#{here}_#{there.gsub(/-/, '_')}"
+end
+
+input = $stdin.readlines.map(&:chomp)
+lines = []
+labels = {}
+
+input.each_with_index do |line, i|
+  istr = line.split
+  case istr[0]
+  when 'set'
+    lines << "#{istr[1]} = #{istr[2]};"
+  when 'sub'
+    lines << "#{istr[1]} -= #{istr[2]};"
+  when 'mul'
+    lines << "#{istr[1]} *= #{istr[2]};"
+  when 'jnz'
+    lab = gen_label(i, istr[2])
+    lines << "if (#{istr[1]}) goto #{lab};"
+    jmp = istr[2].to_i
+    labels[i+jmp] = [] if labels[i+jmp].nil?
+    labels[i+jmp] << "#{lab}:"
+  end
+end
+
+labels.keys.sort.reverse.each do |i|
+  labels[i].each do |lab|
+    lines.insert(i, lab)
+  end
+end
+
+puts <<EOT
+#include <stdio.h>
+
+void main() {
+  int
+    a = 1,
+    b = 0,
+    c = 0,
+    d = 0,
+    e = 0,
+    f = 0,
+    g = 0,
+    h = 0;
+
+// BEGIN GENERATED CODE BLOCK
+
+EOT
+
+lines.each do |line|
+  puts "#{line[0] == "l" ? "" : "  "}  #{line}"
+end
+
+puts <<EOT
+
+//END GENERATED CODE BLOCK
+
+  printf("%d\\n", h);
+}
+EOT
diff --git a/day23/part2rb b/day23/part2rb
new file mode 100755
index 0000000..b00d666
--- /dev/null
+++ b/day23/part2rb
@@ -0,0 +1,34 @@
+#!/usr/bin/env ruby
+
+def valof(reg_file, reg_or_int)
+  if reg_or_int >= 'a' && reg_or_int <= 'z' then
+    return reg_file[reg_or_int] || 0
+  end
+  return reg_or_int.to_i
+end
+
+input = $stdin.readlines.map(&:chomp)
+
+reg = {'a' => 1}
+pc = 0
+
+loop do
+  break if pc < 0 || pc >= input.length
+  istr = input[pc].split
+  case istr[0]
+  when 'set'
+    reg[istr[1]] = valof(reg, istr[2])
+  when 'sub'
+    reg[istr[1]] = valof(reg, istr[1]) - valof(reg, istr[2])
+  when 'mul'
+    reg[istr[1]] = valof(reg, istr[1]) * valof(reg, istr[2])
+  when 'jnz'
+    if valof(reg, istr[1]) != 0 then
+      pc += valof(reg, istr[2])
+      pc -= 1
+    end
+  end
+  pc += 1
+end
+
+puts reg['h']
-- 
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