| /* APPLE LOCAL file lno */ |
| /* { dg-do compile } */ |
| /* { dg-options "-O1 -floop-test -fdump-tree-lptest-details" } */ |
| |
| /* That's a reduced testcase of one of my favourite simulation programs. |
| This is also known under the name: "Newton's falling apple". |
| The general version is known under the name: "the N-body simulation problem". |
| |
| The physics terminology is the best to describe the scalar evolution algorithm: |
| - first determine the initial conditions of the system, |
| - then analyze its evolution. |
| */ |
| |
| double Newton_s_apple () |
| { |
| /* Initial conditions. */ |
| double g = -10.0; |
| double speed_z = 0; |
| double altitude = 3000; |
| double delta_t = 0.1; |
| double total_time = 0; |
| |
| /* Laws of evolution. */ |
| while (altitude > 0.0) |
| { |
| speed_z += g * delta_t; |
| altitude += speed_z * delta_t; |
| total_time += delta_t; |
| } |
| |
| return total_time; |
| } |
| |
| /* |
| speed_z -> {0.0, +, -1.0e+0}_1 |
| altitude -> {3.0e+3, +, {(0.0 + -1.0e+0) * 1.00000000000000005551115123125782702118158340454e-1, +, -1.0e+0 * 1.00000000000000005551115123125782702118158340454e-1}_1}_1 |
| */ |
| |
| /* FIXME. */ |
