Update libjpeg_turbo to 1.4.90 from https://github.com/libjpeg-turbo/

jfdctint.c

 /*
  * jfdctint.c
  *
+ * This file was part of the Independent JPEG Group's software.
  * Copyright (C) 1991-1996, 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 slow-but-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 an algorithm described in
  *   C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
  *   Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
  *   Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
  * The primary algorithm described there uses 11 multiplies and 29 adds.
  * We use their alternate method with 12 multiplies and 32 adds.
  * The advantage of this method is that no data path contains more than one
  * multiplication; this allows a very simple and accurate implementation in
  * scaled fixed-point arithmetic, with a minimal number of shifts.
  */
 
 #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_ISLOW_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 20 matching lines @@
  * multiplication we have to divide the product by CONST_SCALE, with proper
  * rounding, to produce the correct output.  This division can be done
  * cheaply as a right shift of CONST_BITS bits.  We postpone shifting
  * as long as possible so that partial sums can be added together with
  * full fractional precision.
  *
  * The outputs of the first pass are scaled up by PASS1_BITS bits so that
  * they are represented to better-than-integral precision.  These outputs
  * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
  * with the recommended scaling.  (For 12-bit sample data, the intermediate
- * array is INT32 anyway.)
+ * array is JLONG anyway.)
  *
  * To avoid overflow of the 32-bit intermediate results in pass 2, we must
  * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26.  Error analysis
  * shows that the values given below are the most effective.
  */
 
 #if BITS_IN_JSAMPLE == 8
 #define CONST_BITS  13
 #define PASS1_BITS  2
 #else
 #define CONST_BITS  13
-#define PASS1_BITS  1           /* lose a little precision to avoid overflow */
+#define PASS1_BITS  1           /* lose a little precision to avoid overflow */
 #endif
 
 /* 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 == 13
-#define FIX_0_298631336  ((INT32)  2446)        /* FIX(0.298631336) */
-#define FIX_0_390180644  ((INT32)  3196)        /* FIX(0.390180644) */
-#define FIX_0_541196100  ((INT32)  4433)        /* FIX(0.541196100) */
-#define FIX_0_765366865  ((INT32)  6270)        /* FIX(0.765366865) */
-#define FIX_0_899976223  ((INT32)  7373)        /* FIX(0.899976223) */
-#define FIX_1_175875602  ((INT32)  9633)        /* FIX(1.175875602) */
-#define FIX_1_501321110  ((INT32)  12299)       /* FIX(1.501321110) */
-#define FIX_1_847759065  ((INT32)  15137)       /* FIX(1.847759065) */
-#define FIX_1_961570560  ((INT32)  16069)       /* FIX(1.961570560) */
-#define FIX_2_053119869  ((INT32)  16819)       /* FIX(2.053119869) */
-#define FIX_2_562915447  ((INT32)  20995)       /* FIX(2.562915447) */
-#define FIX_3_072711026  ((INT32)  25172)       /* FIX(3.072711026) */
+#define FIX_0_298631336  ((JLONG)  2446)        /* FIX(0.298631336) */
+#define FIX_0_390180644  ((JLONG)  3196)        /* FIX(0.390180644) */
+#define FIX_0_541196100  ((JLONG)  4433)        /* FIX(0.541196100) */
+#define FIX_0_765366865  ((JLONG)  6270)        /* FIX(0.765366865) */
+#define FIX_0_899976223  ((JLONG)  7373)        /* FIX(0.899976223) */
+#define FIX_1_175875602  ((JLONG)  9633)        /* FIX(1.175875602) */
+#define FIX_1_501321110  ((JLONG)  12299)       /* FIX(1.501321110) */
+#define FIX_1_847759065  ((JLONG)  15137)       /* FIX(1.847759065) */
+#define FIX_1_961570560  ((JLONG)  16069)       /* FIX(1.961570560) */
+#define FIX_2_053119869  ((JLONG)  16819)       /* FIX(2.053119869) */
+#define FIX_2_562915447  ((JLONG)  20995)       /* FIX(2.562915447) */
+#define FIX_3_072711026  ((JLONG)  25172)       /* FIX(3.072711026) */
 #else
 #define FIX_0_298631336  FIX(0.298631336)
 #define FIX_0_390180644  FIX(0.390180644)
 #define FIX_0_541196100  FIX(0.541196100)
 #define FIX_0_765366865  FIX(0.765366865)
 #define FIX_0_899976223  FIX(0.899976223)
 #define FIX_1_175875602  FIX(1.175875602)
 #define FIX_1_501321110  FIX(1.501321110)
 #define FIX_1_847759065  FIX(1.847759065)
 #define FIX_1_961570560  FIX(1.961570560)
 #define FIX_2_053119869  FIX(2.053119869)
 #define FIX_2_562915447  FIX(2.562915447)
 #define FIX_3_072711026  FIX(3.072711026)
 #endif
 
 
-/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+/* Multiply an JLONG variable by an JLONG constant to yield an JLONG result.
  * For 8-bit samples with the recommended scaling, all the variable
  * and constant values involved are no more than 16 bits wide, so a
  * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
  * For 12-bit samples, a full 32-bit multiplication will be needed.
  */
 
 #if BITS_IN_JSAMPLE == 8
 #define MULTIPLY(var,const)  MULTIPLY16C16(var,const)
 #else
 #define MULTIPLY(var,const)  ((var) * (const))
 #endif
 
 
 /*
  * Perform the forward DCT on one block of samples.
  */
 
 GLOBAL(void)
-jpeg_fdct_islow (DCTELEM * data)
+jpeg_fdct_islow (DCTELEM *data)
 {
-  INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
-  INT32 tmp10, tmp11, tmp12, tmp13;
-  INT32 z1, z2, z3, z4, z5;
+  JLONG tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+  JLONG tmp10, tmp11, tmp12, tmp13;
+  JLONG z1, z2, z3, z4, z5;
   DCTELEM *dataptr;
   int ctr;
   SHIFT_TEMPS
 
   /* Pass 1: process rows. */
   /* Note results are scaled up by sqrt(8) compared to a true DCT; */
   /* furthermore, we scale the results by 2**PASS1_BITS. */
 
   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 per LL&M figure 1 --- note that published figure is faulty;
      * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
      */
-    
+
     tmp10 = tmp0 + tmp3;
     tmp13 = tmp0 - tmp3;
     tmp11 = tmp1 + tmp2;
     tmp12 = tmp1 - tmp2;
-    
-    dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);
-    dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
-    
+
+    dataptr[0] = (DCTELEM) LEFT_SHIFT(tmp10 + tmp11, PASS1_BITS);
+    dataptr[4] = (DCTELEM) LEFT_SHIFT(tmp10 - tmp11, PASS1_BITS);
+
     z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
     dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
-                                   CONST_BITS-PASS1_BITS);
+                                   CONST_BITS-PASS1_BITS);
     dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
-                                   CONST_BITS-PASS1_BITS);
-    
+                                   CONST_BITS-PASS1_BITS);
+
     /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
      * cK represents cos(K*pi/16).
      * i0..i3 in the paper are tmp4..tmp7 here.
      */
-    
+
     z1 = tmp4 + tmp7;
     z2 = tmp5 + tmp6;
     z3 = tmp4 + tmp6;
     z4 = tmp5 + tmp7;
     z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
-    
+
     tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
     tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
     tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
     tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
     z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
     z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
     z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
     z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
-    
+
     z3 += z5;
     z4 += z5;
-    
+
     dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);
     dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);
     dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);
     dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);
-    
-    dataptr += DCTSIZE;         /* advance pointer to next row */
+
+    dataptr += DCTSIZE;         /* advance pointer to next row */
   }
 
   /* Pass 2: process columns.
    * We remove the PASS1_BITS scaling, but leave the results scaled up
    * by an overall factor of 8.
    */
 
   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 per LL&M figure 1 --- note that published figure is faulty;
      * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
      */
-    
+
     tmp10 = tmp0 + tmp3;
     tmp13 = tmp0 - tmp3;
     tmp11 = tmp1 + tmp2;
     tmp12 = tmp1 - tmp2;
-    
+
     dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS);
     dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS);
-    
+
     z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
     dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
-                                           CONST_BITS+PASS1_BITS);
+                                           CONST_BITS+PASS1_BITS);
     dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
-                                           CONST_BITS+PASS1_BITS);
-    
+                                           CONST_BITS+PASS1_BITS);
+
     /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
      * cK represents cos(K*pi/16).
      * i0..i3 in the paper are tmp4..tmp7 here.
      */
-    
+
     z1 = tmp4 + tmp7;
     z2 = tmp5 + tmp6;
     z3 = tmp4 + tmp6;
     z4 = tmp5 + tmp7;
     z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
-    
+
     tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
     tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
     tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
     tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
     z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
     z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
     z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
     z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
-    
+
     z3 += z5;
     z4 += z5;
-    
+
     dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp4 + z1 + z3,
-                                           CONST_BITS+PASS1_BITS);
+                                           CONST_BITS+PASS1_BITS);
     dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp5 + z2 + z4,
-                                           CONST_BITS+PASS1_BITS);
+                                           CONST_BITS+PASS1_BITS);
     dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp6 + z2 + z3,
-                                           CONST_BITS+PASS1_BITS);
+                                           CONST_BITS+PASS1_BITS);
     dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp7 + z1 + z4,
-                                           CONST_BITS+PASS1_BITS);
-    
-    dataptr++;                  /* advance pointer to next column */
+                                           CONST_BITS+PASS1_BITS);
+
+    dataptr++;                  /* advance pointer to next column */
   }
 }
 
 #endif /* DCT_ISLOW_SUPPORTED */