; This testcase is distilled from the GNU rx package. The loop should be ; removed but causes a problem when ADCE does. The source function is: ; int rx_bitset_empty (int size, rx_Bitset set) { ; int x; ; RX_subset s; ; s = set[0]; ; set[0] = 1; ; for (x = rx_bitset_numb_subsets(size) - 1; !set[x]; --x) ; ; ; set[0] = s; ; return !s; ;} ; ; RUN: opt < %s -adce define i32 @rx_bitset_empty(i32 %size, i32* %set) { bb1: %reg110 = load i32* %set ; <i32> [#uses=2] store i32 1, i32* %set %cast112 = sext i32 %size to i64 ; <i64> [#uses=1] %reg113 = add i64 %cast112, 31 ; <i64> [#uses=1] %reg114 = lshr i64 %reg113, 5 ; <i64> [#uses=2] %cast109 = trunc i64 %reg114 to i32 ; <i32> [#uses=1] %reg129 = add i32 %cast109, -1 ; <i32> [#uses=1] %reg114-idxcast = trunc i64 %reg114 to i32 ; <i32> [#uses=1] %reg114-idxcast-offset = add i32 %reg114-idxcast, 1073741823 ; <i32> [#uses=1] %reg114-idxcast-offset.upgrd.1 = zext i32 %reg114-idxcast-offset to i64 ; <i64> [#uses=1] %reg124 = getelementptr i32* %set, i64 %reg114-idxcast-offset.upgrd.1 ; <i32*> [#uses=1] %reg125 = load i32* %reg124 ; <i32> [#uses=1] %cond232 = icmp ne i32 %reg125, 0 ; <i1> [#uses=1] br i1 %cond232, label %bb3, label %bb2 bb2: ; preds = %bb2, %bb1 %cann-indvar = phi i32 [ 0, %bb1 ], [ %add1-indvar, %bb2 ] ; <i32> [#uses=2] %reg130-scale = mul i32 %cann-indvar, -1 ; <i32> [#uses=1] %reg130 = add i32 %reg130-scale, %reg129 ; <i32> [#uses=1] %add1-indvar = add i32 %cann-indvar, 1 ; <i32> [#uses=1] %reg130-idxcast = bitcast i32 %reg130 to i32 ; <i32> [#uses=1] %reg130-idxcast-offset = add i32 %reg130-idxcast, 1073741823 ; <i32> [#uses=1] %reg130-idxcast-offset.upgrd.2 = zext i32 %reg130-idxcast-offset to i64 ; <i64> [#uses=1] %reg118 = getelementptr i32* %set, i64 %reg130-idxcast-offset.upgrd.2 ; <i32*> [#uses=1] %reg119 = load i32* %reg118 ; <i32> [#uses=1] %cond233 = icmp eq i32 %reg119, 0 ; <i1> [#uses=1] br i1 %cond233, label %bb2, label %bb3 bb3: ; preds = %bb2, %bb1 store i32 %reg110, i32* %set %cast126 = zext i32 %reg110 to i64 ; <i64> [#uses=1] %reg127 = add i64 %cast126, -1 ; <i64> [#uses=1] %reg128 = lshr i64 %reg127, 63 ; <i64> [#uses=1] %cast120 = trunc i64 %reg128 to i32 ; <i32> [#uses=1] ret i32 %cast120 }