1572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams/* 2572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * Copyright (C) 2013 The Android Open Source Project 3572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * 4572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * Licensed under the Apache License, Version 2.0 (the "License"); 5572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * you may not use this file except in compliance with the License. 6572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * You may obtain a copy of the License at 7572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * 8572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * http://www.apache.org/licenses/LICENSE-2.0 9572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * 10572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * Unless required by applicable law or agreed to in writing, software 11572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * distributed under the License is distributed on an "AS IS" BASIS, 12572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * See the License for the specific language governing permissions and 14572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams * limitations under the License. 15572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams */ 16572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 17572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams#pragma version(1) 18572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams#pragma rs java_package_name(com.example.android.rs.matherr) 19572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 20572a5031a5d8602db0bec0b253428a034bd4dd59Jason Samstypedef union 21572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams{ 22572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams float fv; 23572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams int32_t iv; 24572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams} ieee_float_shape_type; 25572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 26572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams/* Get a 32 bit int from a float. */ 27572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 28572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams#define GET_FLOAT_WORD(i,d) \ 29572a5031a5d8602db0bec0b253428a034bd4dd59Jason Samsdo { \ 30572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams ieee_float_shape_type gf_u; \ 31572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams gf_u.fv = (d); \ 32572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (i) = gf_u.iv; \ 33572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams} while (0) 34572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 35572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams/* Set a float from a 32 bit int. */ 36572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 37572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams#define SET_FLOAT_WORD(d,i) \ 38572a5031a5d8602db0bec0b253428a034bd4dd59Jason Samsdo { \ 39572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams ieee_float_shape_type sf_u; \ 40572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams sf_u.iv = (i); \ 41572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (d) = sf_u.fv; \ 42572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams} while (0) 43572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 44572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 45572a5031a5d8602db0bec0b253428a034bd4dd59Jason Samsstatic float fast_log2(float v) { 46572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams int32_t ibits; 47572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams GET_FLOAT_WORD(ibits, v); 48572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 49572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams int32_t e = (ibits >> 23) & 0xff; 50572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 51572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams ibits &= 0x7fffff; 52572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams ibits |= 127 << 23; 53572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 54572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams float ir; 55572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams SET_FLOAT_WORD(ir, ibits); 56572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 57572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams ir -= 1.5f; 58572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams float ir2 = ir*ir; 59572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams float adj2 = 0.405465108f + // -0.00009f + 60572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (0.666666667f * ir) - 61572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (0.222222222f * ir2) + 62572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (0.098765432f * ir*ir2) - 63572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (0.049382716f * ir2*ir2) + 64572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (0.026337449f * ir*ir2*ir2) - 65572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams (0.014631916f * ir2*ir2*ir2); 66572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams adj2 *= (1.f / 0.693147181f); 67572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 68572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams return (float)(e - 127) + adj2; 69572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams} 70572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 71572a5031a5d8602db0bec0b253428a034bd4dd59Jason Samsvoid testExp2(const float *in, float *out) { 72572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams float i = *in; 73572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams if (i > (-125.f) && i < 125.f) { 74572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams *out = native_exp2(i); 75572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams } else { 76572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams *out = exp2(i); 77572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams } 78572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams *out = native_exp2(i); 79572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams} 80572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 81572a5031a5d8602db0bec0b253428a034bd4dd59Jason Samsvoid testLog2(const float *in, float *out) { 82572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams *out = fast_log2(*in); 83572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams} 84572a5031a5d8602db0bec0b253428a034bd4dd59Jason Sams 85