Index: libjpeg6b-6b/jdcolor.c
===================================================================
--- libjpeg6b-6b.orig/jdcolor.c	2006-08-08 20:44:25.677065367 -0700
+++ libjpeg6b-6b/jdcolor.c	2006-08-08 20:46:42.067842752 -0700
@@ -118,20 +118,22 @@
 
 METHODDEF(void)
 ycc_rgb_convert (j_decompress_ptr cinfo,
-		 JSAMPIMAGE input_buf, JDIMENSION input_row,
-		 JSAMPARRAY output_buf, int num_rows)
+		 JSAMPIMAGE __restrict input_buf, JDIMENSION input_row,
+		 JSAMPARRAY __restrict output_buf, int num_rows)
 {
   my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
   register int y, cb, cr;
-  register JSAMPROW outptr;
-  register JSAMPROW inptr0, inptr1, inptr2;
+  register JSAMPROW __restrict outptr;
+  register JSAMPROW __restrict inptr0;
+  register JSAMPROW __restrict inptr1;
+  register JSAMPROW __restrict inptr2;
   register JDIMENSION col;
   JDIMENSION num_cols = cinfo->output_width;
   /* copy these pointers into registers if possible */
-  register int * Crrtab = cconvert->Cr_r_tab;
-  register int * Cbbtab = cconvert->Cb_b_tab;
-  register INT32 * Crgtab = cconvert->Cr_g_tab;
-  register INT32 * Cbgtab = cconvert->Cb_g_tab;
+  register int * __restrict Crrtab = cconvert->Cr_r_tab;
+  register int * __restrict Cbbtab = cconvert->Cb_b_tab;
+  register INT32 * __restrict Crgtab = cconvert->Cr_g_tab;
+  register INT32 * __restrict Cbgtab = cconvert->Cb_g_tab;
   SHIFT_TEMPS
 
   while (--num_rows >= 0) {
@@ -140,18 +142,30 @@
     inptr2 = input_buf[2][input_row];
     input_row++;
     outptr = *output_buf++;
-    for (col = 0; col < num_cols; col++) {
-      y  = GETJSAMPLE(inptr0[col]);
-      cb = GETJSAMPLE(inptr1[col]);
-      cr = GETJSAMPLE(inptr2[col]);
-      /* Range-limiting is essential due to noise introduced by DCT losses. */
-      outptr[RGB_RED] =   jsample_range_limit(y + Crrtab[cr]);
-      outptr[RGB_GREEN] = jsample_range_limit(y +
-			      ((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
-						 SCALEBITS)));
-      outptr[RGB_BLUE] =  jsample_range_limit(y + Cbbtab[cb]);
-      outptr += RGB_PIXELSIZE;
+    col = 0;
+    while (col < num_cols - 3) {
+#define XX do {\
+	y  = GETJSAMPLE(inptr0[col]); \
+	cb = GETJSAMPLE(inptr1[col]); \
+	cr = GETJSAMPLE(inptr2[col]); \
+	/* Range-limiting is essential due to noise introduced by DCT losses. */ \
+	outptr[RGB_RED] =   jsample_range_limit(y + Crrtab[cr]); \
+	outptr[RGB_GREEN] = jsample_range_limit(y + \
+				((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], \
+						  SCALEBITS))); \
+	outptr[RGB_BLUE] =  jsample_range_limit(y + Cbbtab[cb]); \
+	outptr += RGB_PIXELSIZE; \
+	++col; \
+      } while(0)
+      XX;
+      XX;
+      XX;
+      XX;
+    }
+    while (col < num_cols) {
+      XX;
     }
+#undef XX
   }
 }