35 lines
		
	
	
		
			814 B
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			35 lines
		
	
	
		
			814 B
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt < %s -S -indvars -loop-unroll | FileCheck %s
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| ;
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| ; PR15570: SEGV: SCEV back-edge info invalid after dead code removal.
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| ;
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| ; Indvars creates a SCEV expression for the loop's back edge taken
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| ; count, then determines that the comparison is always true and
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| ; removes it.
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| ;
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| ; When loop-unroll asks for the expression, it contains a NULL
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| ; SCEVUnknkown (as a CallbackVH).
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| ;
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| ; forgetMemoizedResults should invalidate the backedge taken count expression.
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| 
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| ; CHECK: @test
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| ; CHECK-NOT: phi
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| ; CHECK-NOT: icmp
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| ; CHECK: ret void
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| define void @test() {
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| entry:
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|   %xor1 = xor i32 0, 1
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|   br label %b17
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| 
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| b17:
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|   br i1 undef, label %b22, label %b18
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| 
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| b18:
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|   %phi1 = phi i32 [ %add1, %b18 ], [ %xor1, %b17 ]
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|   %add1 = add nsw i32 %phi1, -1
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|   %cmp1 = icmp sgt i32 %add1, 0
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|   br i1 %cmp1, label %b18, label %b22
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| 
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| b22:
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|   ret void
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| }
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