Imported Upstream version 5.18.0.161

Former-commit-id: 4db48158d3a35497b8f118ab21b5f08ac3d86d98

external/llvm/test/Transforms/LICM/2003-05-02-LoadHoist.ll

@@ -0,0 +1,23 @@
+; 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
+}