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Diffstat (limited to 'benchmarks/CUDA/BlackScholes/BlackScholes_kernel.cuh')
| -rw-r--r-- | benchmarks/CUDA/BlackScholes/BlackScholes_kernel.cuh | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/benchmarks/CUDA/BlackScholes/BlackScholes_kernel.cuh b/benchmarks/CUDA/BlackScholes/BlackScholes_kernel.cuh new file mode 100644 index 0000000..d99f69a --- /dev/null +++ b/benchmarks/CUDA/BlackScholes/BlackScholes_kernel.cuh @@ -0,0 +1,122 @@ +/* + * Copyright 1993-2007 NVIDIA Corporation. All rights reserved. + * + * NOTICE TO USER: + * + * This source code is subject to NVIDIA ownership rights under U.S. and + * international Copyright laws. Users and possessors of this source code + * are hereby granted a nonexclusive, royalty-free license to use this code + * in individual and commercial software. + * + * NVIDIA MAKES NO REPRESENTATION ABOUT THE SUITABILITY OF THIS SOURCE + * CODE FOR ANY PURPOSE. IT IS PROVIDED "AS IS" WITHOUT EXPRESS OR + * IMPLIED WARRANTY OF ANY KIND. NVIDIA DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOURCE CODE, INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE. + * IN NO EVENT SHALL NVIDIA BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL, + * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS + * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE + * OR PERFORMANCE OF THIS SOURCE CODE. + * + * U.S. Government End Users. This source code is a "commercial item" as + * that term is defined at 48 C.F.R. 2.101 (OCT 1995), consisting of + * "commercial computer software" and "commercial computer software + * documentation" as such terms are used in 48 C.F.R. 12.212 (SEPT 1995) + * and is provided to the U.S. Government only as a commercial end item. + * Consistent with 48 C.F.R.12.212 and 48 C.F.R. 227.7202-1 through + * 227.7202-4 (JUNE 1995), all U.S. Government End Users acquire the + * source code with only those rights set forth herein. + * + * Any use of this source code in individual and commercial software must + * include, in the user documentation and internal comments to the code, + * the above Disclaimer and U.S. Government End Users Notice. + */ + + + +/////////////////////////////////////////////////////////////////////////////// +// Polynomial approximation of cumulative normal distribution function +/////////////////////////////////////////////////////////////////////////////// +__device__ inline float cndGPU(float d){ + const float A1 = 0.31938153f; + const float A2 = -0.356563782f; + const float A3 = 1.781477937f; + const float A4 = -1.821255978f; + const float A5 = 1.330274429f; + const float RSQRT2PI = 0.39894228040143267793994605993438f; + + float + K = 1.0f / (1.0f + 0.2316419f * fabsf(d)); + + float + cnd = RSQRT2PI * __expf(- 0.5f * d * d) * + (K * (A1 + K * (A2 + K * (A3 + K * (A4 + K * A5))))); + + if(d > 0) + cnd = 1.0f - cnd; + + return cnd; +} + + +/////////////////////////////////////////////////////////////////////////////// +// Black-Scholes formula for both call and put +/////////////////////////////////////////////////////////////////////////////// +__device__ inline void BlackScholesBodyGPU( + float& CallResult, + float& PutResult, + float S, //Stock price + float X, //Option strike + float T, //Option years + float R, //Riskless rate + float V //Volatility rate +){ + float sqrtT, expRT; + float d1, d2, CNDD1, CNDD2; + + sqrtT = sqrtf(T); + d1 = (__logf(S / X) + (R + 0.5f * V * V) * T) / (V * sqrtT); + d2 = d1 - V * sqrtT; + + CNDD1 = cndGPU(d1); + CNDD2 = cndGPU(d2); + + //Calculate Call and Put simultaneously + expRT = __expf(- R * T); + CallResult = S * CNDD1 - X * expRT * CNDD2; + PutResult = X * expRT * (1.0f - CNDD2) - S * (1.0f - CNDD1); +} + + +//////////////////////////////////////////////////////////////////////////////// +//Process an array of optN options on GPU +//////////////////////////////////////////////////////////////////////////////// +__global__ void BlackScholesGPU( + float *d_CallResult, + float *d_PutResult, + float *d_StockPrice, + float *d_OptionStrike, + float *d_OptionYears, + float Riskfree, + float Volatility, + int optN +){ + //Thread index + const int tid = blockDim.x * blockIdx.x + threadIdx.x; + //Total number of threads in execution grid + const int THREAD_N = blockDim.x * gridDim.x; + + //No matter how small is execution grid or how large OptN is, + //exactly OptN indices will be processed with perfect memory coalescing + for(int opt = tid; opt < optN; opt += THREAD_N) + BlackScholesBodyGPU( + d_CallResult[opt], + d_PutResult[opt], + d_StockPrice[opt], + d_OptionStrike[opt], + d_OptionYears[opt], + Riskfree, + Volatility + ); +} |
