35 lines
		
	
	
		
			805 B
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			35 lines
		
	
	
		
			805 B
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck %s
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define void @redundant_add(i64 %n) {
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; Check that we don't create two additions for the sadd.with.overflow.
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; CHECK-LABEL: redundant_add
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; CHECK-NOT:  leaq
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; CHECK-NOT:  addq
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; CHECK:      incq
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; CHECK-NEXT: jno
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entry:
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  br label %exit_check
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exit_check:
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  %i = phi i64 [ 0, %entry ], [ %i.next, %loop ]
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  %c = icmp slt i64 %i, %n
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  br i1 %c, label %loop, label %exit
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loop:
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  %i.o = tail call { i64, i1 } @llvm.sadd.with.overflow.i64(i64 %i, i64 1)
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  %i.next = extractvalue { i64, i1 } %i.o, 0
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  %o = extractvalue { i64, i1 } %i.o, 1
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  br i1 %o, label %overflow, label %exit_check
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exit:
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  ret void
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overflow:
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  tail call void @llvm.trap()
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  unreachable
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}
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declare { i64, i1 } @llvm.sadd.with.overflow.i64(i64, i64)
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declare void @llvm.trap()
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