Update to libjpeg_turbo 1.4.90

jfdctfst.c

 /*
  * jfdctfst.c
  *
+ * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1994-1996, Thomas G. Lane.
- * This file is part of the Independent JPEG Group's software.
- * For conditions of distribution and use, see the accompanying README file.
+ * libjpeg-turbo Modifications:
+ * Copyright (C) 2015, D. R. Commander
+ * For conditions of distribution and use, see the accompanying README.ijg
+ * file.
  *
  * This file contains a fast, not so accurate integer implementation of the
  * forward DCT (Discrete Cosine Transform).
  *
  * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
  * on each column.  Direct algorithms are also available, but they are
  * much more complex and seem not to be any faster when reduced to code.
  *
  * This implementation is based on Arai, Agui, and Nakajima's algorithm for
  * scaled DCT.  Their original paper (Trans. IEICE E-71(11):1095) is in
  * Japanese, but the algorithm is described in the Pennebaker & Mitchell
- * JPEG textbook (see REFERENCES section in file README).  The following code
- * is based directly on figure 4-8 in P&M.
+ * JPEG textbook (see REFERENCES section in file README.ijg).  The following
+ * code is based directly on figure 4-8 in P&M.
  * While an 8-point DCT cannot be done in less than 11 multiplies, it is
  * possible to arrange the computation so that many of the multiplies are
  * simple scalings of the final outputs.  These multiplies can then be
  * folded into the multiplications or divisions by the JPEG quantization
  * table entries.  The AA&N method leaves only 5 multiplies and 29 adds
  * to be done in the DCT itself.
  * The primary disadvantage of this method is that with fixed-point math,
  * accuracy is lost due to imprecise representation of the scaled
  * quantization values.  The smaller the quantization table entry, the less
  * precise the scaled value, so this implementation does worse with high-
  * quality-setting files than with low-quality ones.
  */
 
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
-#include "jdct.h"               /* Private declarations for DCT subsystem */
+#include "jdct.h"               /* Private declarations for DCT subsystem */
 
 #ifdef DCT_IFAST_SUPPORTED
 
 
 /*
  * This module is specialized to the case DCTSIZE = 8.
  */
 
 #if DCTSIZE != 8
   Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
@@ skipping 22 matching lines @@
 
 
 /* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
  * causing a lot of useless floating-point operations at run time.
  * To get around this we use the following pre-calculated constants.
  * If you change CONST_BITS you may want to add appropriate values.
  * (With a reasonable C compiler, you can just rely on the FIX() macro...)
  */
 
 #if CONST_BITS == 8
-#define FIX_0_382683433  ((INT32)   98)         /* FIX(0.382683433) */
-#define FIX_0_541196100  ((INT32)  139)         /* FIX(0.541196100) */
-#define FIX_0_707106781  ((INT32)  181)         /* FIX(0.707106781) */
-#define FIX_1_306562965  ((INT32)  334)         /* FIX(1.306562965) */
+#define FIX_0_382683433  ((JLONG)   98)         /* FIX(0.382683433) */
+#define FIX_0_541196100  ((JLONG)  139)         /* FIX(0.541196100) */
+#define FIX_0_707106781  ((JLONG)  181)         /* FIX(0.707106781) */
+#define FIX_1_306562965  ((JLONG)  334)         /* FIX(1.306562965) */
 #else
 #define FIX_0_382683433  FIX(0.382683433)
 #define FIX_0_541196100  FIX(0.541196100)
 #define FIX_0_707106781  FIX(0.707106781)
 #define FIX_1_306562965  FIX(1.306562965)
 #endif
 
 
 /* We can gain a little more speed, with a further compromise in accuracy,
  * by omitting the addition in a descaling shift.  This yields an incorrectly
  * rounded result half the time...
  */
 
 #ifndef USE_ACCURATE_ROUNDING
 #undef DESCALE
 #define DESCALE(x,n)  RIGHT_SHIFT(x, n)
 #endif
 
 
-/* Multiply a DCTELEM variable by an INT32 constant, and immediately
+/* Multiply a DCTELEM variable by an JLONG constant, and immediately
  * descale to yield a DCTELEM result.
  */
 
 #define MULTIPLY(var,const)  ((DCTELEM) DESCALE((var) * (const), CONST_BITS))
 
 
 /*
  * Perform the forward DCT on one block of samples.
  */
 
 GLOBAL(void)
-jpeg_fdct_ifast (DCTELEM * data)
+jpeg_fdct_ifast (DCTELEM *data)
 {
   DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
   DCTELEM tmp10, tmp11, tmp12, tmp13;
   DCTELEM z1, z2, z3, z4, z5, z11, z13;
   DCTELEM *dataptr;
   int ctr;
   SHIFT_TEMPS
 
   /* Pass 1: process rows. */
 
   dataptr = data;
   for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
     tmp0 = dataptr[0] + dataptr[7];
     tmp7 = dataptr[0] - dataptr[7];
     tmp1 = dataptr[1] + dataptr[6];
     tmp6 = dataptr[1] - dataptr[6];
     tmp2 = dataptr[2] + dataptr[5];
     tmp5 = dataptr[2] - dataptr[5];
     tmp3 = dataptr[3] + dataptr[4];
     tmp4 = dataptr[3] - dataptr[4];
-    
+
     /* Even part */
-    
-    tmp10 = tmp0 + tmp3;        /* phase 2 */
+
+    tmp10 = tmp0 + tmp3;        /* phase 2 */
     tmp13 = tmp0 - tmp3;
     tmp11 = tmp1 + tmp2;
     tmp12 = tmp1 - tmp2;
-    
+
     dataptr[0] = tmp10 + tmp11; /* phase 3 */
     dataptr[4] = tmp10 - tmp11;
-    
+
     z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781); /* c4 */
-    dataptr[2] = tmp13 + z1;    /* phase 5 */
+    dataptr[2] = tmp13 + z1;    /* phase 5 */
     dataptr[6] = tmp13 - z1;
-    
+
     /* Odd part */
 
-    tmp10 = tmp4 + tmp5;        /* phase 2 */
+    tmp10 = tmp4 + tmp5;        /* phase 2 */
     tmp11 = tmp5 + tmp6;
     tmp12 = tmp6 + tmp7;
 
     /* The rotator is modified from fig 4-8 to avoid extra negations. */
     z5 = MULTIPLY(tmp10 - tmp12, FIX_0_382683433); /* c6 */
     z2 = MULTIPLY(tmp10, FIX_0_541196100) + z5; /* c2-c6 */
     z4 = MULTIPLY(tmp12, FIX_1_306562965) + z5; /* c2+c6 */
     z3 = MULTIPLY(tmp11, FIX_0_707106781); /* c4 */
 
-    z11 = tmp7 + z3;            /* phase 5 */
+    z11 = tmp7 + z3;            /* phase 5 */
     z13 = tmp7 - z3;
 
-    dataptr[5] = z13 + z2;      /* phase 6 */
+    dataptr[5] = z13 + z2;      /* phase 6 */
     dataptr[3] = z13 - z2;
     dataptr[1] = z11 + z4;
     dataptr[7] = z11 - z4;
 
-    dataptr += DCTSIZE;         /* advance pointer to next row */
+    dataptr += DCTSIZE;         /* advance pointer to next row */
   }
 
   /* Pass 2: process columns. */
 
   dataptr = data;
   for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
     tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
     tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
     tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
     tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
     tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
     tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
     tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
     tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
-    
+
     /* Even part */
-    
-    tmp10 = tmp0 + tmp3;        /* phase 2 */
+
+    tmp10 = tmp0 + tmp3;        /* phase 2 */
     tmp13 = tmp0 - tmp3;
     tmp11 = tmp1 + tmp2;
     tmp12 = tmp1 - tmp2;
-    
+
     dataptr[DCTSIZE*0] = tmp10 + tmp11; /* phase 3 */
     dataptr[DCTSIZE*4] = tmp10 - tmp11;
-    
+
     z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781); /* c4 */
     dataptr[DCTSIZE*2] = tmp13 + z1; /* phase 5 */
     dataptr[DCTSIZE*6] = tmp13 - z1;
-    
+
     /* Odd part */
 
-    tmp10 = tmp4 + tmp5;        /* phase 2 */
+    tmp10 = tmp4 + tmp5;        /* phase 2 */
     tmp11 = tmp5 + tmp6;
     tmp12 = tmp6 + tmp7;
 
     /* The rotator is modified from fig 4-8 to avoid extra negations. */
     z5 = MULTIPLY(tmp10 - tmp12, FIX_0_382683433); /* c6 */
     z2 = MULTIPLY(tmp10, FIX_0_541196100) + z5; /* c2-c6 */
     z4 = MULTIPLY(tmp12, FIX_1_306562965) + z5; /* c2+c6 */
     z3 = MULTIPLY(tmp11, FIX_0_707106781); /* c4 */
 
-    z11 = tmp7 + z3;            /* phase 5 */
+    z11 = tmp7 + z3;            /* phase 5 */
     z13 = tmp7 - z3;
 
     dataptr[DCTSIZE*5] = z13 + z2; /* phase 6 */
     dataptr[DCTSIZE*3] = z13 - z2;
     dataptr[DCTSIZE*1] = z11 + z4;
     dataptr[DCTSIZE*7] = z11 - z4;
 
-    dataptr++;                  /* advance pointer to next column */
+    dataptr++;                  /* advance pointer to next column */
   }
 }
 
 #endif /* DCT_IFAST_SUPPORTED */