2008-11-03-Invariant.ll   [plain text]

; RUN: llvm-as < %s | opt -loop-unswitch -stats -disable-output |& grep "1 loop-unswitch - Number of branches unswitched" | count 1
; PR 3170
define i32 @a(i32 %x, i32 %y) nounwind {
entry:
	%0 = icmp ult i32 0, %y		; <i1> [#uses=1]
	br i1 %0, label %bb.nph, label %bb4

bb.nph:		; preds = %entry
	%1 = icmp eq i32 %x, 0		; <i1> [#uses=1]
	br label %bb

bb:		; preds = %bb.nph, %bb3
	%i.01 = phi i32 [ %3, %bb3 ], [ 0, %bb.nph ]		; <i32> [#uses=1]
	br i1 %1, label %bb2, label %bb1

bb1:		; preds = %bb
	%2 = tail call i32 (...)* @b() nounwind		; <i32> [#uses=0]
	br label %bb2

bb2:		; preds = %bb, %bb1
	%3 = add i32 %i.01, 1		; <i32> [#uses=2]
	br label %bb3

bb3:		; preds = %bb2
	%i.0 = phi i32 [ %3, %bb2 ]		; <i32> [#uses=1]
	%4 = icmp ult i32 %i.0, %y		; <i1> [#uses=1]
	br i1 %4, label %bb, label %bb3.bb4_crit_edge

bb3.bb4_crit_edge:		; preds = %bb3
	br label %bb4

bb4:		; preds = %bb3.bb4_crit_edge, %entry
	ret i32 0
}

declare i32 @b(...)