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Diffstat (limited to 'gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-44.c')
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-44.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-44.c b/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-44.c new file mode 100644 index 00000000000..1a3099a90a6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-44.c @@ -0,0 +1,38 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fscalar-evolutions -fdump-tree-scev-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. */ |