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