From d45dbeb48a9da2ccfc1dd3fc0f3baea4c365e086 Mon Sep 17 00:00:00 2001
From: jakob <jakob@memeware.net>
Date: Sat, 18 Mar 2017 18:07:39 -0400
Subject: The compilation process now includes *very* minimal code
 optimization.

---
 skullfuck.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 48 insertions(+), 5 deletions(-)

(limited to 'skullfuck.c')

diff --git a/skullfuck.c b/skullfuck.c
index 7d9e0a8..b40e903 100644
--- a/skullfuck.c
+++ b/skullfuck.c
@@ -29,9 +29,13 @@
 #define ARCH         "x86_64"
 #define OS           "Linux"
 #define INC_DATA_PTR "\tincq %rsi\n"
+#define ADD_DATA_PTR "\taddq $0x%x, %%rsi\n"
 #define DEC_DATA_PTR "\tdecq %rsi\n"
+#define SUB_DATA_PTR "\tsubq $0x%x, %%rsi\n"
 #define INC_DATA     "\tincb (%rsi)\n"
+#define ADD_DATA     "\taddb $0x%x, (%%rsi)\n"
 #define DEC_DATA     "\tdecb (%rsi)\n"
+#define SUB_DATA     "\tsubb $0x%x, (%%rsi)\n"
 #define PRINT_DATA   "\tmovq $0x01, %rax\n" \
                      "\tmovq $0x01, %rdi\n" \
                      "\tsyscall\n"
@@ -58,9 +62,13 @@
 #define ARCH         "i686"
 #define OS           "Linux"
 #define INC_DATA_PTR "\tincl %ecx\n"
+#define ADD_DATA_PTR "\taddl $0x%x, %%ecx\n"
 #define DEC_DATA_PTR "\tdecl %ecx\n"
+#define SUB_DATA_PTR "\tsubl $0x%x, %%ecx\n"
 #define INC_DATA     "\tincb (%ecx)\n"
+#define ADD_DATA     "\taddb $0x%x, (%%ecx)\n"
 #define DEC_DATA     "\tdecb (%ecx)\n"
+#define SUB_DATA     "\tsubb $0x%x, (%%ecx)\n"
 #define PRINT_DATA   "\tmovl $0x04, %eax\n" \
                      "\tmovl $0x01, %ebx\n" \
                      "\tint $0x80\n"
@@ -121,26 +129,57 @@ static int pop_loop_index(struct loop_stack *s) {
 }
 
 
+/* Minor optimization subroutine. Increments the `in` pointer to beyond
+   the collection of adjacent `op` characters, and returns the number
+   of operations counted. */
+static int reduce(char **in, char op) {
+    int  i;
+    for (i = 0; (*in)[i] == op; i++);
+    *in += i - 1;
+    return i;
+}
+
+
 /* Converts the brainfuck instructions read from `in` to assembly
    instructions and writes them to `out`. `in` is expected to be
    null-terminated. */
 static void write_instructions(FILE *out, char *in) {
-    int               next_loop = 0, cur_loop = 0;
+    int               next_loop = 0, cur_loop = 0, op_count;
     struct loop_stack *loops = calloc(sizeof(struct loop_stack), 1);
 
     for (char *cur = in; *cur != '\0'; cur++) {
         switch(*cur) {
             case '>':
-                fputs(INC_DATA_PTR, out);
+                op_count = reduce(&cur, '>');
+                if (op_count > 1) {
+                    fprintf(out, ADD_DATA_PTR, op_count);
+                } else {
+                    fputs(INC_DATA_PTR, out);
+                }
                 break;
             case '<':
-                fputs(DEC_DATA_PTR, out);
+                op_count = reduce(&cur, '<');
+                if (op_count > 1) {
+                    fprintf(out, SUB_DATA_PTR, op_count);
+                } else {
+                    fputs(DEC_DATA_PTR, out);
+                }
                 break;
             case '+':
-                fputs(INC_DATA, out);
+                op_count = reduce(&cur, '+');
+                if (op_count > 1) {
+                    fprintf(out, ADD_DATA, op_count);
+                } else {
+                    fputs(INC_DATA, out);
+                }
                 break;
             case '-':
-                fputs(DEC_DATA, out);
+                op_count = reduce(&cur, '-');
+                if (op_count > 1) {
+                    fprintf(out, SUB_DATA, op_count);
+                } else {
+                    fputs(DEC_DATA, out);
+                }
                 break;
             case '.':
                 fputs(PRINT_DATA, out);
@@ -223,6 +262,10 @@ static void create_binary(struct params p) {
             wait(NULL);
         }
     }
+
+    if (!p.compile_only)
+        remove("/tmp/skullfuck_tmp.s");
+    remove("/tmp/skullfuck_tmp.o");
 }
 
 
-- 
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