llvm/test/Transforms/SCCP/2002-05-02-EdgeFailure.ll
Dan Gohman f2f6ce65b7 Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81537 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-11 18:01:28 +00:00

27 lines
915 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: opt < %s -sccp -S | not grep loop
define i32* @test() {
bb1:
%A = malloc i32 ; <i32*> [#uses=2]
br label %bb2
bb2: ; preds = %bb2, %bb1
;; Always 0
%i = phi i32 [ %i2, %bb2 ], [ 0, %bb1 ] ; <i32> [#uses=2]
;; Always 1
%i2 = add i32 %i, 1 ; <i32> [#uses=2]
store i32 %i, i32* %A
;; Always false
%loop = icmp sle i32 %i2, 0 ; <i1> [#uses=1]
br i1 %loop, label %bb2, label %bb3
bb3: ; preds = %bb2
ret i32* %A
}