Libav 0.7.1
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00001 /* 00002 * GMC (Global Motion Compensation) 00003 * AltiVec-enabled 00004 * Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org> 00005 * 00006 * This file is part of Libav. 00007 * 00008 * Libav is free software; you can redistribute it and/or 00009 * modify it under the terms of the GNU Lesser General Public 00010 * License as published by the Free Software Foundation; either 00011 * version 2.1 of the License, or (at your option) any later version. 00012 * 00013 * Libav is distributed in the hope that it will be useful, 00014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00016 * Lesser General Public License for more details. 00017 * 00018 * You should have received a copy of the GNU Lesser General Public 00019 * License along with Libav; if not, write to the Free Software 00020 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00021 */ 00022 00023 #include "libavcodec/dsputil.h" 00024 #include "util_altivec.h" 00025 #include "types_altivec.h" 00026 #include "dsputil_altivec.h" 00027 00028 /* 00029 altivec-enhanced gmc1. ATM this code assume stride is a multiple of 8, 00030 to preserve proper dst alignment. 00031 */ 00032 void gmc1_altivec(uint8_t *dst /* align 8 */, uint8_t *src /* align1 */, int stride, int h, int x16, int y16, int rounder) 00033 { 00034 const DECLARE_ALIGNED(16, unsigned short, rounder_a) = rounder; 00035 const DECLARE_ALIGNED(16, unsigned short, ABCD)[8] = 00036 { 00037 (16-x16)*(16-y16), /* A */ 00038 ( x16)*(16-y16), /* B */ 00039 (16-x16)*( y16), /* C */ 00040 ( x16)*( y16), /* D */ 00041 0, 0, 0, 0 /* padding */ 00042 }; 00043 register const vector unsigned char vczero = (const vector unsigned char)vec_splat_u8(0); 00044 register const vector unsigned short vcsr8 = (const vector unsigned short)vec_splat_u16(8); 00045 register vector unsigned char dstv, dstv2, src_0, src_1, srcvA, srcvB, srcvC, srcvD; 00046 register vector unsigned short Av, Bv, Cv, Dv, rounderV, tempA, tempB, tempC, tempD; 00047 int i; 00048 unsigned long dst_odd = (unsigned long)dst & 0x0000000F; 00049 unsigned long src_really_odd = (unsigned long)src & 0x0000000F; 00050 00051 tempA = vec_ld(0, (unsigned short*)ABCD); 00052 Av = vec_splat(tempA, 0); 00053 Bv = vec_splat(tempA, 1); 00054 Cv = vec_splat(tempA, 2); 00055 Dv = vec_splat(tempA, 3); 00056 00057 rounderV = vec_splat((vec_u16)vec_lde(0, &rounder_a), 0); 00058 00059 // we'll be able to pick-up our 9 char elements 00060 // at src from those 32 bytes 00061 // we load the first batch here, as inside the loop 00062 // we can re-use 'src+stride' from one iteration 00063 // as the 'src' of the next. 00064 src_0 = vec_ld(0, src); 00065 src_1 = vec_ld(16, src); 00066 srcvA = vec_perm(src_0, src_1, vec_lvsl(0, src)); 00067 00068 if (src_really_odd != 0x0000000F) { 00069 // if src & 0xF == 0xF, then (src+1) is properly aligned 00070 // on the second vector. 00071 srcvB = vec_perm(src_0, src_1, vec_lvsl(1, src)); 00072 } else { 00073 srcvB = src_1; 00074 } 00075 srcvA = vec_mergeh(vczero, srcvA); 00076 srcvB = vec_mergeh(vczero, srcvB); 00077 00078 for(i=0; i<h; i++) { 00079 dst_odd = (unsigned long)dst & 0x0000000F; 00080 src_really_odd = (((unsigned long)src) + stride) & 0x0000000F; 00081 00082 dstv = vec_ld(0, dst); 00083 00084 // we we'll be able to pick-up our 9 char elements 00085 // at src + stride from those 32 bytes 00086 // then reuse the resulting 2 vectors srvcC and srcvD 00087 // as the next srcvA and srcvB 00088 src_0 = vec_ld(stride + 0, src); 00089 src_1 = vec_ld(stride + 16, src); 00090 srcvC = vec_perm(src_0, src_1, vec_lvsl(stride + 0, src)); 00091 00092 if (src_really_odd != 0x0000000F) { 00093 // if src & 0xF == 0xF, then (src+1) is properly aligned 00094 // on the second vector. 00095 srcvD = vec_perm(src_0, src_1, vec_lvsl(stride + 1, src)); 00096 } else { 00097 srcvD = src_1; 00098 } 00099 00100 srcvC = vec_mergeh(vczero, srcvC); 00101 srcvD = vec_mergeh(vczero, srcvD); 00102 00103 00104 // OK, now we (finally) do the math :-) 00105 // those four instructions replaces 32 int muls & 32 int adds. 00106 // isn't AltiVec nice ? 00107 tempA = vec_mladd((vector unsigned short)srcvA, Av, rounderV); 00108 tempB = vec_mladd((vector unsigned short)srcvB, Bv, tempA); 00109 tempC = vec_mladd((vector unsigned short)srcvC, Cv, tempB); 00110 tempD = vec_mladd((vector unsigned short)srcvD, Dv, tempC); 00111 00112 srcvA = srcvC; 00113 srcvB = srcvD; 00114 00115 tempD = vec_sr(tempD, vcsr8); 00116 00117 dstv2 = vec_pack(tempD, (vector unsigned short)vczero); 00118 00119 if (dst_odd) { 00120 dstv2 = vec_perm(dstv, dstv2, vcprm(0,1,s0,s1)); 00121 } else { 00122 dstv2 = vec_perm(dstv, dstv2, vcprm(s0,s1,2,3)); 00123 } 00124 00125 vec_st(dstv2, 0, dst); 00126 00127 dst += stride; 00128 src += stride; 00129 } 00130 }