30 lines
		
	
	
		
			953 B
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			30 lines
		
	
	
		
			953 B
		
	
	
	
		
			LLVM
		
	
	
	
; NOTE: Assertions have been autogenerated by update_test_checks.py
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; Test merging of blocks that only have PHI nodes in them
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;
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; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
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;
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define i32 @test(i1 %a, i1 %b) {
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; CHECK-LABEL: @test(
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; CHECK:       M:
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; CHECK-NEXT:    [[DOT:%.*]] = select i1 %b, i32 0, i32 1
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; CHECK-NEXT:    [[W:%.*]] = select i1 %a, i32 2, i32 [[DOT]]
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; CHECK-NEXT:    [[R:%.*]] = add i32 [[W]], 1
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; CHECK-NEXT:    ret i32 [[R]]
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;
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  br i1 %a, label %M, label %O
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O:              ; preds = %0
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  br i1 %b, label %N, label %Q
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Q:              ; preds = %O
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  br label %N
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N:              ; preds = %Q, %O
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  ; This block should be foldable into M
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  %Wp = phi i32 [ 0, %O ], [ 1, %Q ]              ; <i32> [#uses=1]
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  br label %M
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M:              ; preds = %N, %0
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  %W = phi i32 [ %Wp, %N ], [ 2, %0 ]             ; <i32> [#uses=1]
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  %R = add i32 %W, 1              ; <i32> [#uses=1]
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  ret i32 %R
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}
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