Make the SSE code optional.

diff --git a/qscale.c b/qscale.c
index ca7c7dd16152fac40c672e35898ea4450ec680a4..d89c8b9463d9a34cc367a22f72f4e4b9f75a7b7d 100644 (file)
--- a/qscale.c
+++ b/qscale.c
@@ -23,8 +23,20 @@
 #include <stdlib.h>
 #include "jpeglib.h"
 
+/* The number of pixels to process at a time when scaling vertically. */
 #define CACHE_LINE_FACTOR 16
 
+/* Whether to use SSE for horizontal scaling or not (requires SSE3). */
+#define USE_HORIZONTAL_SSE 1
+
+/* Whether to use SSE for vertical scaling or not (requires only SSE1). */
+#define USE_VERTICAL_SSE 1
+
+#if USE_VERTICAL_SSE
+#undef CACHE_LINE_FACTOR
+#define CACHE_LINE_FACTOR 16
+#endif
+
 #ifndef M_PI
 #define M_PI 3.14159265358979323846264
 #endif
@@ -84,6 +96,7 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
                        end = w - 1;
                }
 
+#if USE_HORIZONTAL_SSE
                /* round up so we get a multiple of four for the SSE code */
                int num = (end - start + 1);
                if (num % 4 != 0) {
@@ -96,6 +109,7 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
                                end += 4 - (num % 4);
                        }
                }
+#endif
 
                pd[x].start = start;
                pd[x].end = end;
@@ -123,6 +137,7 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
                unsigned char *dptr = npix + y*dstride;
                unsigned char ch;
                for (x = 0; x < nw; ++x) {
+#if USE_HORIZONTAL_SSE
                        int result;
                        float acc;
                        long tmp;
@@ -154,7 +169,16 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
                                : "memory", "xmm1", "xmm2"
                        );
 
-#if 0
+                       *dptr++ = (unsigned char)result;
+#else
+                       float acc = 0.0;
+                       float *cf = &coeffs[pd[x].startcoeff];
+                       unsigned sx;
+                       
+                       for (sx = pd[x].start; sx <= pd[x].end; ++sx) {
+                               acc += sptr[sx] * *cf++;
+                       }
+
                        if (acc < 0.0)
                                ch = 0;
                        else if (acc > 255.0)
@@ -163,7 +187,6 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
                                ch = (unsigned char)acc;
                        *dptr++ = ch;
 #endif
-                       *dptr++ = (unsigned char)result;
                }
                ch = dptr[-1];
                for ( ; x < dstride; ++x) {
@@ -221,25 +244,7 @@ void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh
                unsigned char *sptr = pix + x;
                float *dptr = npix + x;
                for (y = 0; y < nh; ++y) {
-#if 0
-                       int i;
-                       float acc[CACHE_LINE_FACTOR];
-                       for (i = 0; i < CACHE_LINE_FACTOR; ++i)
-                               acc[i] = 0.0;
-                       float *cf = &coeffs[pd[y].startcoeff];
-                       unsigned sy;
-               
-                       for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
-                               for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
-                                       acc[i] += sptr[sy * w + i] * *cf;
-                               }
-                               ++cf;
-                       }
-
-                       for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
-                               dptr[i] = acc[i];
-                       }
-#else
+#if USE_VERTICAL_SSE
                        /*
                         * xmm0 - xmm3: acc[0..15]
                         * xmm4: current filter coefficient
@@ -327,6 +332,24 @@ void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh
                                "r" (dptr)                           /* 4: dstptr base */
                                : "memory", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7"
                        );
+#else
+                       int i;
+                       float acc[CACHE_LINE_FACTOR];
+                       for (i = 0; i < CACHE_LINE_FACTOR; ++i)
+                               acc[i] = 0.0;
+                       float *cf = &coeffs[pd[y].startcoeff];
+                       unsigned sy;
+               
+                       for (sy = pd[y].start; sy <= pd[y].end; ++sy) {
+                               for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
+                                       acc[i] += sptr[sy * w + i] * *cf;
+                               }
+                               ++cf;
+                       }
+
+                       for (i = 0; i < CACHE_LINE_FACTOR; ++i) {
+                               dptr[i] = acc[i];
+                       }
 #endif
                        dptr += dstride;
                }