From: Josh Coalson <jcoalson@users.sourceforce.net>
Date: Wed, 24 Jan 2007 04:23:53 +0000 (+0000)
Subject: minor optimizations
X-Git-Tag: 1.2.0~206
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f5dd47832d34bdf688d53e17e87c4a174e9474aa;p=platform%2Fupstream%2Fflac.git

minor optimizations
---

diff --git a/src/libFLAC/fixed.c b/src/libFLAC/fixed.c
index d432962..a87e6c6 100644
--- a/src/libFLAC/fixed.c
+++ b/src/libFLAC/fixed.c
@@ -34,6 +34,7 @@
 #endif
 
 #include <math.h>
+#include <string.h>
 #include "private/bitmath.h"
 #include "private/fixed.h"
 #include "FLAC/assert.h"
@@ -355,32 +356,36 @@ void FLAC__fixed_compute_residual(const FLAC__int32 data[], unsigned data_len, u
 
 	switch(order) {
 		case 0:
-			for(i = 0; i < idata_len; i++) {
-				residual[i] = data[i];
-			}
+			FLAC__ASSERT(sizeof(residual[0]) == sizeof(data[0]));
+			memcpy(residual, data, sizeof(residual[0])*data_len);
 			break;
 		case 1:
-			for(i = 0; i < idata_len; i++) {
+			for(i = 0; i < idata_len; i++)
 				residual[i] = data[i] - data[i-1];
-			}
 			break;
 		case 2:
-			for(i = 0; i < idata_len; i++) {
-				/* == data[i] - 2*data[i-1] + data[i-2] */
+			for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
 				residual[i] = data[i] - (data[i-1] << 1) + data[i-2];
-			}
+#else
+				residual[i] = data[i] - 2*data[i-1] + data[i-2];
+#endif
 			break;
 		case 3:
-			for(i = 0; i < idata_len; i++) {
-				/* == data[i] - 3*data[i-1] + 3*data[i-2] - data[i-3] */
+			for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
 				residual[i] = data[i] - (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) - data[i-3];
-			}
+#else
+				residual[i] = data[i] - 3*data[i-1] + 3*data[i-2] - data[i-3];
+#endif
 			break;
 		case 4:
-			for(i = 0; i < idata_len; i++) {
-				/* == data[i] - 4*data[i-1] + 6*data[i-2] - 4*data[i-3] + data[i-4] */
+			for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
 				residual[i] = data[i] - ((data[i-1]+data[i-3])<<2) + ((data[i-2]<<2) + (data[i-2]<<1)) + data[i-4];
-			}
+#else
+				residual[i] = data[i] - 4*data[i-1] + 6*data[i-2] - 4*data[i-3] + data[i-4];
+#endif
 			break;
 		default:
 			FLAC__ASSERT(0);
@@ -393,32 +398,36 @@ void FLAC__fixed_restore_signal(const FLAC__int32 residual[], unsigned data_len,
 
 	switch(order) {
 		case 0:
-			for(i = 0; i < idata_len; i++) {
-				data[i] = residual[i];
-			}
+			FLAC__ASSERT(sizeof(residual[0]) == sizeof(data[0]));
+			memcpy(data, residual, sizeof(residual[0])*data_len);
 			break;
 		case 1:
-			for(i = 0; i < idata_len; i++) {
+			for(i = 0; i < idata_len; i++)
 				data[i] = residual[i] + data[i-1];
-			}
 			break;
 		case 2:
-			for(i = 0; i < idata_len; i++) {
-				/* == residual[i] + 2*data[i-1] - data[i-2] */
+			for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
 				data[i] = residual[i] + (data[i-1]<<1) - data[i-2];
-			}
+#else
+				data[i] = residual[i] + 2*data[i-1] - data[i-2];
+#endif
 			break;
 		case 3:
-			for(i = 0; i < idata_len; i++) {
-				/* residual[i] + 3*data[i-1] - 3*data[i-2]) + data[i-3] */
+			for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
 				data[i] = residual[i] + (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) + data[i-3];
-			}
+#else
+				data[i] = residual[i] + 3*data[i-1] - 3*data[i-2] + data[i-3];
+#endif
 			break;
 		case 4:
-			for(i = 0; i < idata_len; i++) {
-				/* == residual[i] + 4*data[i-1] - 6*data[i-2] + 4*data[i-3] - data[i-4] */
+			for(i = 0; i < idata_len; i++)
+#if 1 /* OPT: may be faster with some compilers on some systems */
 				data[i] = residual[i] + ((data[i-1]+data[i-3])<<2) - ((data[i-2]<<2) + (data[i-2]<<1)) - data[i-4];
-			}
+#else
+				data[i] = residual[i] + 4*data[i-1] - 6*data[i-2] + 4*data[i-3] - data[i-4];
+#endif
 			break;
 		default:
 			FLAC__ASSERT(0);