mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-23 15:29:51 +00:00
e78760e179
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8558 91177308-0d34-0410-b5e6-96231b3b80d8
24 lines
827 B
LLVM
24 lines
827 B
LLVM
; 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
|
|
}
|