; 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: llvm-upgrade < %s | llvm-as | opt -adce implementation ; Functions: int %rx_bitset_empty(int %size, uint* %set) { bb1: ;[#uses=2] %reg110 = load uint* %set ; [#uses=2] store uint 1, uint* %set %cast112 = cast int %size to ulong ; [#uses=1] %reg113 = add ulong %cast112, 31 ; [#uses=1] %reg114 = shr ulong %reg113, ubyte 5 ; [#uses=2] %cast109 = cast ulong %reg114 to int ; [#uses=1] %reg129 = add int %cast109, -1 ; [#uses=1] %reg114-idxcast = cast ulong %reg114 to uint ; [#uses=1] %reg114-idxcast-offset = add uint %reg114-idxcast, 1073741823 ; [#uses=1] %reg114-idxcast-offset = cast uint %reg114-idxcast-offset to long %reg124 = getelementptr uint* %set, long %reg114-idxcast-offset ; [#uses=1] %reg125 = load uint* %reg124 ; [#uses=1] %cond232 = setne uint %reg125, 0 ; [#uses=1] br bool %cond232, label %bb3, label %bb2 bb2: ;[#uses=3] %cann-indvar = phi int [ 0, %bb1 ], [ %add1-indvar, %bb2 ] ; [#uses=2] %reg130-scale = mul int %cann-indvar, -1 ; [#uses=1] %reg130 = add int %reg130-scale, %reg129 ; [#uses=1] %add1-indvar = add int %cann-indvar, 1 ; [#uses=1] %reg130-idxcast = cast int %reg130 to uint ; [#uses=1] %reg130-idxcast-offset = add uint %reg130-idxcast, 1073741823 ; [#uses=1] %reg130-idxcast-offset = cast uint %reg130-idxcast-offset to long %reg118 = getelementptr uint* %set, long %reg130-idxcast-offset ; [#uses=1] %reg119 = load uint* %reg118 ; [#uses=1] %cond233 = seteq uint %reg119, 0 ; [#uses=1] br bool %cond233, label %bb2, label %bb3 bb3: ;[#uses=2] store uint %reg110, uint* %set %cast126 = cast uint %reg110 to ulong ; [#uses=1] %reg127 = add ulong %cast126, 18446744073709551615 ; [#uses=1] %reg128 = shr ulong %reg127, ubyte 63 ; [#uses=1] %cast120 = cast ulong %reg128 to int ; [#uses=1] ret int %cast120 }