1 ; RUN: llc < %s -march=arm64 2 3 ; This test case tests an infinite loop bug in DAG combiner. 4 ; It just tries to do the following replacing endlessly: 5 ; (1) Replacing.3 0x2c509f0: v4i32 = any_extend 0x2c4cd08 [ORD=4] 6 ; With: 0x2c4d128: v4i32 = sign_extend 0x2c4cd08 [ORD=4] 7 ; 8 ; (2) Replacing.2 0x2c4d128: v4i32 = sign_extend 0x2c4cd08 [ORD=4] 9 ; With: 0x2c509f0: v4i32 = any_extend 0x2c4cd08 [ORD=4] 10 ; As we think the (2) optimization from SIGN_EXTEND to ANY_EXTEND is 11 ; an optimization to replace unused bits with undefined bits, we remove 12 ; the (1) optimization (It doesn't make sense to replace undefined bits 13 ; with signed bits). 14 15 define <4 x i32> @infiniteLoop(<4 x i32> %in0, <4 x i16> %in1) { 16 entry: 17 %cmp.i = icmp sge <4 x i16> %in1, <i16 32767, i16 32767, i16 -1, i16 -32768> 18 %sext.i = sext <4 x i1> %cmp.i to <4 x i32> 19 %mul.i = mul <4 x i32> %in0, %sext.i 20 %sext = shl <4 x i32> %mul.i, <i32 16, i32 16, i32 16, i32 16> 21 %vmovl.i.i = ashr <4 x i32> %sext, <i32 16, i32 16, i32 16, i32 16> 22 ret <4 x i32> %vmovl.i.i 23 }
