| ; edgefailure - This function illustrates how SCCP is not doing it's job. This |
| ; function should be optimized almost completely away: the loop should be |
| ; analyzed to detect that the body executes exactly once, and thus the branch |
| ; can be eliminated and code becomes trivially dead. This is distilled from a |
| ; real benchmark (mst from Olden benchmark, MakeGraph function). When SCCP is |
| ; fixed, this should be eliminated by a single SCCP application. |
| ; |
| ; RUN: llvm-as < %s | opt -sccp | llvm-dis | not grep loop |
| |
| int* %test() { |
| bb1: |
| %A = malloc int |
| br label %bb2 |
| bb2: |
| %i = phi int [ %i2, %bb2 ], [ 0, %bb1 ] ;; Always 0 |
| %i2 = add int %i, 1 ;; Always 1 |
| store int %i, int *%A |
| %loop = setle int %i2, 0 ;; Always false |
| br bool %loop, label %bb2, label %bb3 |
| |
| bb3: |
| ret int * %A |
| } |
