1 files changed, 50 insertions, 0 deletions
diff --git a/test/Transforms/LICM/hoisting.ll b/test/Transforms/LICM/hoisting.ll
new file mode 100644
index 0000000..e7d36af
--- /dev/null
+++ b/test/Transforms/LICM/hoisting.ll
@@ -0,0 +1,50 @@
+; RUN: opt < %s -licm -S | FileCheck %s
+
+@X = global i32 0		; <i32*> [#uses=1]
+
+declare void @foo()
+
+; This testcase tests for a problem where LICM hoists 
+; potentially trapping instructions when they are not guaranteed to execute.
+define i32 @test1(i1 %c) {
+; CHECK: @test1
+	%A = load i32* @X		; <i32> [#uses=2]
+	br label %Loop
+Loop:		; preds = %LoopTail, %0
+	call void @foo( )
+	br i1 %c, label %LoopTail, label %IfUnEqual
+        
+IfUnEqual:		; preds = %Loop
+; CHECK: IfUnEqual:
+; CHECK-NEXT: sdiv i32 4, %A
+	%B1 = sdiv i32 4, %A		; <i32> [#uses=1]
+	br label %LoopTail
+        
+LoopTail:		; preds = %IfUnEqual, %Loop
+	%B = phi i32 [ 0, %Loop ], [ %B1, %IfUnEqual ]		; <i32> [#uses=1]
+	br i1 %c, label %Loop, label %Out
+Out:		; preds = %LoopTail
+	%C = sub i32 %A, %B		; <i32> [#uses=1]
+	ret i32 %C
+}
+
+
+declare void @foo2(i32)
+
+
+;; It is ok and desirable to hoist this potentially trapping instruction.
+define i32 @test2(i1 %c) {
+; CHECK: @test2
+; CHECK-NEXT: load i32* @X
+; CHECK-NEXT: %B = sdiv i32 4, %A
+	%A = load i32* @X		; <i32> [#uses=2]
+	br label %Loop
+Loop:
+        ;; Should have hoisted this div!
+	%B = sdiv i32 4, %A		; <i32> [#uses=2]
+	call void @foo2( i32 %B )
+	br i1 %c, label %Loop, label %Out
+Out:		; preds = %Loop
+	%C = sub i32 %A, %B		; <i32> [#uses=1]
+	ret i32 %C
+}