From 7490aa8e933f2403fa23d1f35ac6f7d1c05e95d9 Mon Sep 17 00:00:00 2001 From: Adrian Kummerlaender Date: Mon, 10 Jun 2019 14:06:02 +0200 Subject: Add fixed velocity boundaries to generated LBM kernel Interestingly this increased performance to ~750 MLUPS compared to ~665 MLUPS. --- codegen_lbm.py | 84 ++++++++++++++++++++++++++++------------------------------ 1 file changed, 41 insertions(+), 43 deletions(-) (limited to 'codegen_lbm.py') diff --git a/codegen_lbm.py b/codegen_lbm.py index cd93649..8e7b0a7 100644 --- a/codegen_lbm.py +++ b/codegen_lbm.py @@ -51,50 +51,48 @@ __kernel void collide_and_stream(__global __write_only float* f_a, const float f_curr_7 = f_i(f_b, cell.x , cell.y+1, 0,-1); const float f_curr_8 = f_i(f_b, cell.x-1, cell.y+1, 1,-1); + const float ux0 = f_curr_3 + f_curr_6; + const float ux1 = f_curr_1 + f_curr_2; + const float ux2 = 1.0/(f_curr_0 + f_curr_4 + f_curr_5 + f_curr_7 + f_curr_8 + ux0 + ux1); + const float ux3 = f_curr_0 - f_curr_8; + + float u_x = -ux2*(-f_curr_2 - f_curr_5 + ux0 + ux3); + float u_y = ux2*(-f_curr_6 - f_curr_7 + ux1 + ux3); + + if ( m == 2 ) { + u_x = 0.0; + u_y = 0.0; + } + const float x0 = f_curr_0 + f_curr_1 + f_curr_2 + f_curr_3 + f_curr_4 + f_curr_5 + f_curr_6 + f_curr_7 + f_curr_8; - const float x1 = 2*f_curr_0; - const float x2 = 2*f_curr_8; - const float x3 = -f_curr_3 + f_curr_5; - const float x4 = pow(x0, -2); - const float x5 = 9*x4; - const float x6 = f_curr_0 - f_curr_8; - const float x7 = f_curr_1 - f_curr_7; - const float x8 = f_curr_2 - f_curr_6; - const float x9 = x6 + x7 + x8; - const float x10 = 6/x0; - const float x11 = x10*x9; - const float x12 = f_curr_3 - f_curr_5; - const float x13 = -f_curr_2 + f_curr_6 + x12 + x6; - const float x14 = pow(x13, 2); - const float x15 = 3*x4; - const float x16 = -x14*x15 + 2; - const float x17 = x11 + x16; - const float x18 = pow(x9, 2); - const float x19 = x15*x18; - const float x20 = -x19; - const float x21 = x10*x13; - const float x22 = x20 + x21; - const float x23 = 1.0/$tau; - const float x24 = (1.0/72.0)*x23; - const float x25 = 6*x4; - const float x26 = x18*x25; - const float x27 = (1.0/18.0)*x23; - const float x28 = x5*pow(2*f_curr_2 - 2*f_curr_6 + x3 + x7, 2); - const float x29 = x20 - x21; - const float x30 = x14*x25 + 2; - const float x31 = -f_curr_0 + f_curr_8 + x3 + x8; - const float x32 = x15*pow(x31, 2) - 2; - const float x33 = x19 + x32; - - f_a[0*$nCells + gid] = f_curr_0 - x24*(72*f_curr_0 - x0*(x17 + x22 + x5*pow(-f_curr_1 + f_curr_7 - x1 + x2 + x3, 2))); - f_a[1*$nCells + gid] = f_curr_1 - x27*(18*f_curr_1 - x0*(x17 + x26)); - f_a[2*$nCells + gid] = f_curr_2 - x24*(72*f_curr_2 - x0*(x17 + x28 + x29)); - f_a[3*$nCells + gid] = f_curr_3 - x27*(18*f_curr_3 - x0*(x22 + x30)); - f_a[4*$nCells + gid] = f_curr_4 - 1.0/9.0*x23*(9*f_curr_4 + 2*x0*x33); - f_a[5*$nCells + gid] = f_curr_5 - x27*(18*f_curr_5 - x0*(x29 + x30)); - f_a[6*$nCells + gid] = f_curr_6 - x24*(72*f_curr_6 + x0*(x10*x31 + x11 - x28 + x33)); - f_a[7*$nCells + gid] = f_curr_7 - x27*(18*f_curr_7 + x0*(x11 - x26 + x32)); - f_a[8*$nCells + gid] = f_curr_8 - x24*(72*f_curr_8 - x0*(-x11 + x16 + x29 + x5*pow(x1 + x12 - x2 + x7, 2))); + const float x1 = 6*u_y; + const float x2 = 6*u_x; + const float x3 = pow(u_y, 2); + const float x4 = 3*x3; + const float x5 = pow(u_x, 2); + const float x6 = 3*x5; + const float x7 = x6 - 2; + const float x8 = x4 + x7; + const float x9 = x2 + x8; + const float x10 = 1.0/$tau; + const float x11 = (1.0/72.0)*x10; + const float x12 = 6*x3; + const float x13 = x1 - x6 + 2; + const float x14 = (1.0/18.0)*x10; + const float x15 = -x4; + const float x16 = 9*pow(u_x + u_y, 2); + const float x17 = -x2; + const float x18 = x15 + 6*x5 + 2; + + f_a[0*$nCells + gid] = f_curr_0 - x11*(72*f_curr_0 + x0*(-x1 + x9 - 9*pow(-u_x + u_y, 2))); + f_a[1*$nCells + gid] = f_curr_1 - x14*(18*f_curr_1 - x0*(x12 + x13)); + f_a[2*$nCells + gid] = f_curr_2 - x11*(72*f_curr_2 - x0*(x13 + x15 + x16 + x2)); + f_a[3*$nCells + gid] = f_curr_3 - x14*(18*f_curr_3 - x0*(x17 + x18)); + f_a[4*$nCells + gid] = f_curr_4 - 1.0/9.0*x10*(9*f_curr_4 + 2*x0*x8); + f_a[5*$nCells + gid] = f_curr_5 - x14*(18*f_curr_5 - x0*(x18 + x2)); + f_a[6*$nCells + gid] = f_curr_6 - x11*(72*f_curr_6 + x0*(x1 - x16 + x9)); + f_a[7*$nCells + gid] = f_curr_7 - x14*(18*f_curr_7 + x0*(x1 - x12 + x7)); + f_a[8*$nCells + gid] = f_curr_8 - x11*(72*f_curr_8 + x0*(x1 + x17 + x8 - 9*pow(u_x - u_y, 2))); moments[gid] = x0; }""" -- cgit v1.2.3