我的編譯器,MPLAB C30(GCC V3.23)未編譯此代碼:我的編譯器優化出來的東西,它不應該
if(font_info.flags & FONT_LOWERCASE_ONLY)
ch = tolower(ch);
if(font_info.flags & FONT_UPPERCASE_ONLY)
ch = toupper(ch);
它不產生彙編輸出(以某種方式優化出來)和我無法弄清楚爲什麼。
正確,據我所定義的一切,我可以看到:
#define FONT_LOWERCASE_ONLY 1
#define FONT_UPPERCASE_ONLY 2
struct FontEntry
{
int id;
unsigned char width, height;
const char *name;
const char *lookup;
const char *data;
int flags;
};
struct FontEntry fonts[NUM_FONTS + 1] = {
{ 0, 8, 14, "Outlined8x14", &font_lookup_outlined8x14, &font_data_outlined8x14, 0 },
{ 1, 8, 8, "Outlined8x8", &font_lookup_outlined8x8, &font_data_outlined8x8, FONT_UPPERCASE_ONLY },
{ 2, 8, 8, "Tiny5x5", 0, 0, 0 }, // not yet implemented
{ -1 } // ends font table
};
我使用的功能是:
void write_char(char ch, unsigned int x, unsigned int y, int flags, int font)
{
int i, yy, addr_temp, row, row_temp, xshift;
uint16_t and_mask, or_mask, level_bits;
struct FontEntry font_info;
char lookup;
fetch_font_info(ch, font, &font_info, &lookup);
// ...
}
fetch_font_info的定義:
int fetch_font_info(char ch, int font, struct FontEntry *font_info, char *lookup)
{
// First locate the font struct.
if(font > SIZEOF_ARRAY(fonts))
return 0; // font does not exist, exit.
// Load the font info; IDs are always sequential.
*font_info = fonts[font];
// Locate character in font lookup table. (If required.)
if(lookup != NULL)
{
*lookup = font_info->lookup[ch];
if(lookup == 0xff)
return 0; // character doesn't exist, don't bother writing it.
}
return 1;
}
什麼我做錯了嗎?
顯示font_info的聲明。 – hirschhornsalz 2010-12-04 14:54:07
您需要展示更多的代碼,其中第一個塊出現 – fazo 2010-12-04 15:06:12