| ; This testcase tests for a problem where LICM hoists loads out of a loop |
| ; despite the fact that calls to unknown functions may modify what is being |
| ; loaded from. Basically if the load gets hoisted, the subtract gets turned |
| ; into a constant zero. |
| ; |
| ; RUN: opt < %s -licm -gvn -instcombine -S | grep load |
| |
| @X = global i32 7 ; <i32*> [#uses=2] |
| |
| declare void @foo() |
| |
| define i32 @test(i1 %c) { |
| %A = load i32, i32* @X ; <i32> [#uses=1] |
| br label %Loop |
| Loop: ; preds = %Loop, %0 |
| call void @foo( ) |
| ;; Should not hoist this load! |
| %B = load i32, i32* @X ; <i32> [#uses=1] |
| br i1 %c, label %Loop, label %Out |
| Out: ; preds = %Loop |
| %C = sub i32 %A, %B ; <i32> [#uses=1] |
| ret i32 %C |
| } |
