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comparison libgsmefr/basic_op.h @ 350:9b05bbc23b8a

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libgsmefr inline: make shift count guards 100% robust
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 23 Apr 2024 05:34:54 +0000
parents ed8762eea8a1
children
comparison
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349:ed8762eea8a1 350:9b05bbc23b8a
2 * This version of basic_op.h for GSM-EFR codec has been created at 2 * This version of basic_op.h for GSM-EFR codec has been created at
3 * Themyscira Wireless with the aim of performance improvement. 3 * Themyscira Wireless with the aim of performance improvement.
4 * The original version contained only function declarations, 4 * The original version contained only function declarations,
5 * resulting in a function call for every elementary operation; 5 * resulting in a function call for every elementary operation;
6 * the present version implements most of these operations as inline 6 * the present version implements most of these operations as inline
7 * functions. (Further update: for extra speed-up, the some inline 7 * functions. (Further update: for extra speed-up, some inline
8 * function implementations have been lifted from PacketVideo AMR 8 * function implementations have been lifted from PacketVideo AMR
9 * version, aka libopencore-amrnb.) 9 * version, aka libopencore-amrnb.)
10 * 10 *
11 * Elimination of Overflow flag: examination of EFR code reveals that 11 * Elimination of Overflow flag: examination of EFR code reveals that
12 * both Carry and Overflow flags are accessed outside of basicop2.c 12 * both Carry and Overflow flags are accessed outside of basicop2.c
204 static inline Word16 shl (Word16 var1, Word16 var2) 204 static inline Word16 shl (Word16 var1, Word16 var2)
205 { 205 {
206 Word16 var_out; 206 Word16 var_out;
207 207
208 if (unlikely(var2 < 0)) { 208 if (unlikely(var2 < 0)) {
209 if (unlikely(var2 < -15))
210 var2 = -15;
209 var2 = -var2; 211 var2 = -var2;
210 if (unlikely(var2 > 15))
211 var2 = 15;
212 var_out = var1 >> var2; 212 var_out = var1 >> var2;
213 } else { 213 } else {
214 if (unlikely(var2 > 15)) 214 if (unlikely(var2 > 15))
215 var2 = 15; 215 var2 = 15;
216 var_out = var1 << var2; 216 var_out = var1 << var2;
260 static inline Word16 shr (Word16 var1, Word16 var2) 260 static inline Word16 shr (Word16 var1, Word16 var2)
261 { 261 {
262 Word16 var_out; 262 Word16 var_out;
263 263
264 if (unlikely(var2 < 0)) { 264 if (unlikely(var2 < 0)) {
265 if (unlikely(var2 < -15))
266 var2 = -15;
265 var2 = -var2; 267 var2 = -var2;
266 if (unlikely(var2 > 15))
267 var2 = 15;
268 var_out = var1 << var2; 268 var_out = var1 << var2;
269 if (unlikely(var_out >> var2 != var1)) 269 if (unlikely(var_out >> var2 != var1))
270 { 270 {
271 var_out = (var1 >> 15) ^ MAX_16; 271 var_out = (var1 >> 15) ^ MAX_16;
272 } 272 }
798 static inline Word32 L_shl (Word32 L_var1, Word16 var2) 798 static inline Word32 L_shl (Word32 L_var1, Word16 var2)
799 { 799 {
800 Word32 L_var_out; 800 Word32 L_var_out;
801 801
802 if (unlikely(var2 < 0)) { 802 if (unlikely(var2 < 0)) {
803 if (unlikely(var2 < -31))
804 var2 = -31;
803 var2 = -var2; 805 var2 = -var2;
804 if (unlikely(var2 > 31))
805 var2 = 31;
806 L_var_out = L_var1 >> var2; 806 L_var_out = L_var1 >> var2;
807 } else { 807 } else {
808 if (unlikely(var2 > 31)) 808 if (unlikely(var2 > 31))
809 var2 = 31; 809 var2 = 31;
810 L_var_out = L_var1 << var2; 810 L_var_out = L_var1 << var2;
851 static inline Word32 L_shr (Word32 L_var1, Word16 var2) 851 static inline Word32 L_shr (Word32 L_var1, Word16 var2)
852 { 852 {
853 Word32 L_var_out; 853 Word32 L_var_out;
854 854
855 if (unlikely(var2 < 0)) { 855 if (unlikely(var2 < 0)) {
856 if (unlikely(var2 < -31))
857 var2 = -31;
856 var2 = -var2; 858 var2 = -var2;
857 if (unlikely(var2 > 31))
858 var2 = 31;
859 L_var_out = L_var1 << var2; 859 L_var_out = L_var1 << var2;
860 if (unlikely(L_var_out >> var2 != L_var1)) 860 if (unlikely(L_var_out >> var2 != L_var1))
861 L_var_out = (L_var1 >> 31) ^ MAX_32; 861 L_var_out = (L_var1 >> 31) ^ MAX_32;
862 } else { 862 } else {
863 if (unlikely(var2 > 31)) 863 if (unlikely(var2 > 31))