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use 64-bit-word modification of the lowercase function from the strin…

…gencoders project
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Zachary Schneirov
Zachary Schneirov committed Dec 12, 2009
1 parent 879b6e6 commit 31790a4e2b27ae0314000fc2b610696e1e548413
Showing with 69 additions and 7 deletions.
  1. +68 −6 BufferUtils.c
  2. +1 −1 BufferUtils.h
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@@ -11,6 +11,34 @@
#include <string.h>
//#include "CarbonFSErrorStrings.h"
+static const unsigned char gsToLowerMap[256] = {
+'\0', 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, '\t',
+'\n', 0x0b, 0x0c, '\r', 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13,
+0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d,
+0x1e, 0x1f, ' ', '!', '"', '#', '$', '%', '&', '\'',
+'(', ')', '*', '+', ',', '-', '.', '/', '0', '1',
+'2', '3', '4', '5', '6', '7', '8', '9', ':', ';',
+'<', '=', '>', '?', '@', 'a', 'b', 'c', 'd', 'e',
+'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
+'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y',
+'z', '[', '\\', ']', '^', '_', '`', 'a', 'b', 'c',
+'d', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
+'x', 'y', 'z', '{', '|', '}', '~', 0x7f, 0x80, 0x81,
+0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b,
+0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9,
+0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3,
+0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd,
+0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
+0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1,
+0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb,
+0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5,
+0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
+0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9,
+0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff };
+
#define MIN(a, b) (((a)<(b))?(a):(b))
char *replaceString(char *oldString, const char *newString) {
@@ -45,12 +73,46 @@ int IsZeros(const void *s1, size_t n) {
return (1);
}
-void MakeLowercase(char *text) {
- while (*text!='\0') {
- if (isupper(*text))
- *text=tolower(*text);
- ++text;
- }
+void modp_tolower_copy(char* dest, const char* str, int len) {
+ int i;
+ NSUInteger eax, ebx;
+ const uint8_t* ustr = (const uint8_t*) str;
+ const int leftover = len % sizeof(NSUInteger);
+ const int imax = len / sizeof(NSUInteger);
+ const NSUInteger* s = (const NSUInteger*) str;
+ NSUInteger* d = (NSUInteger*) dest;
+ for (i = 0; i != imax; ++i) {
+ eax = s[i];
+ /*
+ * This is based on the algorithm by Paul Hsieh
+ * http://www.azillionmonkeys.com/qed/asmexample.html
+ */
+#if __LP64__ || NS_BUILD_32_LIKE_64
+ ebx = (0x7f7f7f7f7f7f7f7fllu & eax) + 0x2525252525252525llu;
+ ebx = (0x7f7f7f7f7f7f7f7fllu & ebx) + 0x1a1a1a1a1a1a1a1allu;
+ ebx = ((ebx & ~eax) >> 2) & 0x2020202020202020llu;
+#else
+ ebx = (0x7f7f7f7fu & eax) + 0x25252525u;
+ ebx = (0x7f7f7f7fu & ebx) + 0x1a1a1a1au;
+ ebx = ((ebx & ~eax) >> 2) & 0x20202020u;
+#endif
+ *d++ = eax + ebx;
+ }
+
+ i = imax * sizeof(NSUInteger);
+ dest = (char*) d;
+ switch (leftover) {
+#if __LP64__ || NS_BUILD_32_LIKE_64
+ case 7: *dest++ = (char) gsToLowerMap[ustr[i++]];
+ case 6: *dest++ = (char) gsToLowerMap[ustr[i++]];
+ case 5: *dest++ = (char) gsToLowerMap[ustr[i++]];
+ case 4: *dest++ = (char) gsToLowerMap[ustr[i++]];
+#endif
+ case 3: *dest++ = (char) gsToLowerMap[ustr[i++]];
+ case 2: *dest++ = (char) gsToLowerMap[ustr[i++]];
+ case 1: *dest++ = (char) gsToLowerMap[ustr[i]];
+ case 0: *dest = '\0';
+ }
}
void replace_breaks(char *str, size_t up_to_len) {
View
@@ -13,7 +13,7 @@ char *replaceString(char *oldString, const char *newString);
void ResizeBuffer(void ***buffer, unsigned int objCount, unsigned int *bufSize);
int IsZeros(const void *s1, size_t n);
int ContainsUInteger(const NSUInteger *uintArray, size_t count, NSUInteger auint);
-void MakeLowercase(char *text);
+void modp_tolower_copy(char* dest, const char* str, int len);
void replace_breaks(char *str, size_t up_to_len);
int ContainsHighAscii(const void *s1, size_t n);
CFStringRef CFStringFromBase10Integer(int quantity);

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