SIMD fast path for skipping long multi-line comments. ~190MB/sec

input.c

@@ -8,6 +8,8 @@ multi
 line
 comment */
 
+/* short com */
+
 123
 0707
 0xfAb
@@ -71,10 +73,22 @@ u"\1\12\123"
 U"\xffaab"
 L"\uffFF\xff"
 
-[ ] ( ) { } . ->
+[] ( ) { } . ->
 ++ -- & * + - ~ !
-/ % << >> < > <= >=
+/ % 
+<< 
+>> 
+< 
+> 
+<=
+>=
 ? : ; ...
 = *= /= %= += -= <<=
 , # ##
-<: :> <% %> %: %:%:
+<: 
+:> 
+<% 
+%> %: %:%:
+
+<stdio.h>
+<stdio".h>

main.c

@@ -10,8 +10,9 @@
 
 #include <immintrin.h>
 
-enum token_kind {
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
 
+enum token_kind {
     TOKEN_KEYWORD,
     TOKEN_IDENTIFIER,
     
@@ -58,41 +59,29 @@ advance(struct str *s, int by)
 static int
 nondigit(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || (c == '_'));
-    }
-    return(0);
 }
 
 static int
 digit(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return('0' <= c && c <= '9');
-    }
-    return(0);
 }
 
 static int
 nonzero_digit(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return('1' <= c && c <= '9');
-    }
-    return(0);
 }
 
 static int
 octal_digit(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return('0' <= c && c <= '7');
-    }
-    return(0);
 }
 
 static int
@@ -111,31 +100,22 @@ hexadecimal_prefix(struct str s)
 static int
 hexadecimal_digit(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(digit(s) || ('A' <= c && c <= 'F') || ('a' <= c && c <= 'f'));
-    }
-    return(0);
 }
 
 static int
 unsigned_suffix(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(c == 'u' || c == 'U');
-    }
-    return(0);
 }
 
 static int
 long_suffix(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(c == 'l' || c == 'L');
-    }
-    return(0);
 }
 
 static int
@@ -154,21 +134,15 @@ long_long_suffix(struct str s)
 static int
 sign(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(c == '+' || c == '-');
-    }
-    return(0);
 }
 
 static int
 floating_suffix(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(c == 'f' || c == 'l' || c == 'F' || c == 'L');
-    }
-    return(0);
 }
 
 static int
@@ -291,11 +265,7 @@ hex_quad(struct str s)
 static int
 universal_character_name(struct str s)
 {
-    if (s.size < 2) {
+    if (s.size >= 2 && s.text[0] == '\\') {
-        return(0);
-    }
-    
-    if (s.text[0] == '\\') {
         if (s.text[1] == 'u') {
             advance(&s, 2);
             int hq = hex_quad(s);
@@ -382,7 +352,6 @@ octal_constant(struct str s)
 {
     int start = s.size;
     
-    if (s.size) {
     if (s.text[0] == '0') {
         advance(&s, 1);
         
@@ -396,7 +365,6 @@ octal_constant(struct str s)
         
         return(start - s.size);
     }
-    }
     
     return(0);
 }
@@ -471,7 +439,6 @@ fractional_constant(struct str s)
     s.text += ds1;
     s.size -= ds1;
     
-    if (s.size) {
     if (s.text[0] == '.') {
         advance(&s, 1);
         
@@ -482,7 +449,6 @@ fractional_constant(struct str s)
             return(ds1 + ds2 + 1);
         }
     }
-    }
     
     return(0);
 }
@@ -492,7 +458,6 @@ exponent_part(struct str s)
 {
     int start = s.size;
     
-    if (s.size) {
     if (s.text[0] == 'e' || s.text[0] == 'E') {
         advance(&s, 1);
         
@@ -505,7 +470,6 @@ exponent_part(struct str s)
             return(start - s.size);
         }
     }
-    }
     
     return(0);
 }
@@ -564,7 +528,7 @@ hexadecimal_fractional_constant(struct str s)
     
     advance(&s, hds1);
     
-    if (s.size && s.text[0] == '.') {
+    if (s.text[0] == '.') {
         advance(&s, 1);
         
         int hds2 = hexadecimal_digit_sequence(s);
@@ -582,7 +546,7 @@ binary_exponent_part(struct str s)
 {
     int start = s.size;
     
-    if (s.size && (s.text[0] == 'p' || s.text[0] == 'P')) {
+    if (s.text[0] == 'p' || s.text[0] == 'P') {
         advance(&s, 1);
         
         int sgn = sign(s);
@@ -673,34 +637,23 @@ c_char(struct str s)
         return(sym);
     }
     
-    if (s.size) {
     char c = s.text[0];
-        return(c != '\'' && c != '\\' && c != '\n');
-    }
     
-    return(0);
+    return(c != '\'' && c != '\\' && c != '\n');
 }
 
 static int
 h_char(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(c != '\n' && c != '>');
-    }
-    
-    return(0);
 }
 
 static int
 q_char(struct str s)
 {
-    if (s.size) {
     char c = s.text[0];
     return(c != '\n' && c != '\"');
-    }
-    
-    return(0);
 }
 
 static int
@@ -732,7 +685,7 @@ character_constant(struct str s)
     int start = s.size;
     int ok = 0;
     
-    if (s.size && s.text[0] == '\'') {
+    if (s.text[0] == '\'') {
         advance(&s, 1);
         ok = 1;
     } else if (s.size >= 2 && s.text[0] == 'L' && s.text[1] == '\'') {
@@ -750,7 +703,7 @@ character_constant(struct str s)
         int ccs = c_char_sequence(s);
         if (ccs) {
             advance(&s, ccs);
-            if (s.size && s.text[0] == '\'') {
+            if (s.text[0] == '\'') {
                 advance(&s, 1);
                 return(start - s.size);
             }
@@ -777,8 +730,9 @@ static int
 whitespace(struct str s)
 {
     int start = s.size;
+    //int spaces = 0x20090a0d;
     
-    while (s.size && (s.text[0] == ' ' || s.text[0] == '\t' || s.text[0] == '\n' || s.text[0] == '\r')) {
+    while (s.text[0] == ' ' || s.text[0] == '\t' || s.text[0] == '\n' || s.text[0] == '\r') {
         advance(&s, 1);
     }
     
@@ -794,12 +748,8 @@ s_char(struct str s)
         return(sym);
     }
     
-    if (s.size) {
     char c = s.text[0];
     return(c != '\"' && c != '\\' && c != '\n');
-    }
-    
-    return(0);
 }
 
 static int
@@ -832,14 +782,8 @@ encoding_prefix(struct str s)
         return(2);
     }
     
-    if (s.size) {
     char c = s.text[0];
-        if (c == 'u' || c == 'U' || c == 'L') {
+    return(c == 'u' || c == 'U' || c == 'L');
-            return(1);
-        }
-    }
-    
-    return(0);
 }
 
 static int
@@ -850,13 +794,13 @@ string_literal(struct str s)
     int ep = encoding_prefix(s);
     advance(&s, ep);
     
-    if (s.size && s.text[0] == '\"') {
+    if (s.text[0] == '\"') {
         advance(&s, 1);
         
         int scs = s_char_sequence(s);
         advance(&s, scs);
         
-        if (s.size && s.text[0] == '\"') {
+        if (s.text[0] == '\"') {
             advance(&s, 1);
             return(start - s.size);
         }
@@ -908,7 +852,6 @@ punctuator(struct str s)
         }
     }
     
-    if (s.size) {
     char c = s.text[0];
     if (c == '[' || c == ']' || c == '(' || c == ')' ||
         c == '{' || c == '}' || c == '.' || c == '&' ||
@@ -920,7 +863,6 @@ punctuator(struct str s)
     {
         return(1);
     }
-    }
     
     return(0);
 }
@@ -974,27 +916,27 @@ q_char_sequence(struct str s)
 static int
 header_name(struct str s)
 {
-    if (s.size && s.text[0] == '<') {
+    if (s.text[0] == '<') {
         advance(&s, 1);
         
         int hcs = h_char_sequence(s);
         if (hcs) {
             advance(&s, hcs);
             
-            if (s.size && s.text[0] == '>') {
+            if (s.text[0] == '>') {
                 return(hcs + 2);
             }
         }
     }
     
-    if (s.size && s.text[0] == '\"') {
+    if (s.text[0] == '\"') {
         advance(&s, 1);
         
         int qcs = q_char_sequence(s);
         if (qcs) {
             advance(&s, qcs);
             
-            if (s.size && s.text[0] == '\"') {
+            if (s.text[0] == '\"') {
                 return(qcs + 2);
             }
         }
@@ -1028,6 +970,28 @@ comment(struct str s)
         if (s.text[0] == '/' && s.text[1] == '*') {
             /* multi-line comment */
             
+            
+            advance(&s, 2);
+            
+            __m128i mask = _mm_setr_epi8('*', '/', '*', '/', '*', '/', '*', '/', '*', '/', '*', '/', '*', '/', '*', '/');
+            
+            __m128i mask_sus = _mm_setr_epi8(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, '*'); 
+            
+            while (s.size > 16) {
+                __m128i chunk = _mm_loadu_si128((__m128i *)(s.text));
+                __m128i v1 = _mm_cmpeq_epi16(chunk, mask);
+                __m128i v2 = _mm_cmpeq_epi16(_mm_bslli_si128(chunk, 1), mask);
+                __m128i v3 = _mm_cmpeq_epi8(chunk, mask_sus);
+                __m128i v12 = _mm_or_si128(v1, v2);
+                __m128i v123 = _mm_or_si128(v12, v3);
+                
+                if (!_mm_testz_si128(v123, v123)) {
+                    break;
+                }
+                
+                advance(&s, 16);
+            }
+            
             while (s.size) {
                 if (s.size >= 2 && s.text[0] == '*' && s.text[1] == '/') {
                     advance(&s, 2);
@@ -1057,36 +1021,42 @@ lex(char *text, int size)
         
         if ((sym = comment(s))) {
             //printf("Comment: ");
-        } else if ((sym = constant(s))) {
+            //printf("%.*s\n", sym, s.text);
-            //printf("Constant: ");
+        } else {
+            int sym_constant = constant(s);
+            int sym_punctuator = punctuator(s);
+            int sym_string = string_literal(s);
+            int sym_header = header_name(s);
+            int sym_identifier = identifier(s);
             
+            sym = MAX(sym_constant, MAX(sym_punctuator, MAX(sym_string, MAX(sym_header, sym_identifier))));
             
 #if 0            
-        } else if ((sym == pp_number(s))) {
+            if (sym == sym_constant) {
-            printf("PP number: ");
+                printf("Constant: ");
+            } else if (sym == sym_punctuator) {
+                printf("Punctuator: ");
+            } else if (sym == sym_string) {
+                printf("String: ");
+            } else if (sym == sym_header) {
+                printf("Header: ");
+            } else if (sym == sym_identifier) {
+                printf("Identifier: ");
+            }
 #endif
             
-        } else if ((sym = punctuator(s))) {
-            //printf("Punctuator: ");
-        } else if ((sym = string_literal(s))) {
-            //printf("String literal: ");
-        } else if ((sym = header_name(s))) {
-            //printf("Header name: ");
-        } else if ((sym = identifier(s))) {
-            //printf("Identifier: ");
         }
         
-        //printf("%.*s\n", sym, s.text);
-        
         if (sym) {
             advance(&s, sym);
-        } else if (s.size) {
+        } else if (s.size == 1 && s.text[0] == '\0') {
+            break;
+        } else {
             fprintf(stderr, "Error!\n");
             break;
         }
     }
     
-    
     return(NULL);
 }
 
@@ -1169,6 +1139,13 @@ main(int argc, char **argv)
     int size = (int) sb.st_size;
     
     char *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+    if (size && data[size - 1] != '\n') {
+        fprintf(stderr, "No terminating new line. Fuck you!\n");
+        return(1);
+    }
+    
+    data[size - 1] = '\0';
+    
     if (data == MAP_FAILED) {
         perror("mmap");
         return(1);