Convert a number of places in core and plugins to use the BIT_N() macro instead of 1<<n. Speeds up things on SH1, and also reduces core binsize. Most notable speedups: 1 bit lcd driver: drawpixel +20%, drawline + 27%, hline +5%; jpeg viewer: +8% for 1/8 scaling. Other targets are unaffected.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21205 a1c6a512-1295-4272-9138-f99709370657

apps/plugins/lib/fixedpoint.c

@@ -22,6 +22,7 @@
  ****************************************************************************/
 
 #include <inttypes.h>
+#include "plugin.h"
 #include "fixedpoint.h"
 
 /* Inverse gain of circular cordic rotation in s0.31 format. */
@@ -144,7 +145,7 @@ long fsincos(unsigned long phase, long *cos)
  */
 long fsqrt(long a, unsigned int fracbits)
 {
-    long b = a/2 + (1 << fracbits); /* initial approximation */
+    long b = a/2 + BIT_N(fracbits); /* initial approximation */
     unsigned n;
     const unsigned iterations = 4;
     

apps/plugins/lib/grey_core.c

@@ -860,7 +860,7 @@ static void grey_screendump_hook(int fd)
              + _GREY_MULUQ(_grey_info.width, gy & ~_GREY_BMASK);
 
 #if LCD_DEPTH == 1
-        mask = 1 << (y & 7);
+        mask = BIT_N(y & 7);
         src = rb->lcd_framebuffer + _GREY_MULUQ(LCD_WIDTH, y >> 3);
 
         do

apps/plugins/lib/helper.c

@@ -22,6 +22,20 @@
 #include "plugin.h"
 #include "helper.h"
 
+#ifdef CPU_SH
+/* Lookup table for using the BIT_N() macro in plugins */
+const unsigned bit_n_table[32] = {
+    1LU<< 0, 1LU<< 1, 1LU<< 2, 1LU<< 3,
+    1LU<< 4, 1LU<< 5, 1LU<< 6, 1LU<< 7,
+    1LU<< 8, 1LU<< 9, 1LU<<10, 1LU<<11,
+    1LU<<12, 1LU<<13, 1LU<<14, 1LU<<15,
+    1LU<<16, 1LU<<17, 1LU<<18, 1LU<<19,
+    1LU<<20, 1LU<<21, 1LU<<22, 1LU<<23,
+    1LU<<24, 1LU<<25, 1LU<<26, 1LU<<27,
+    1LU<<28, 1LU<<29, 1LU<<30, 1LU<<31
+};
+#endif
+
 /*  Force the backlight on */
 void backlight_force_on(void)
 {