107 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			107 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -S < %s | FileCheck %s
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| 
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| ; When emitting the memchecks for:
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| ;
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| ;   for (i = 0; i < n; i++) {
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| ;     A[i + 1] = A[i] * B[i];
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| ;     =======================
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| ;     C[i] = D[i] * E[i];
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| ;   }
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| ;
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| ; we had a bug when expanding the bounds for A and C.  These are expanded
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| ; multiple times and rely on the caching in SCEV expansion to avoid any
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| ; redundancy.  However, due to logic in SCEVExpander::ReuseOrCreateCast, we
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| ; can get earlier expanded values invalidated when casts are used.  This test
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| ; ensure that we are not using the invalidated values.
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| 
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| target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
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| 
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| define void @f(i32* %a1, i32* %a2,
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|                i32* %b,
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|                i32* %c1, i32* %c2,
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|                i32* %d,
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|                i32* %e) {
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| entry:
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| 
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|   %cond = icmp eq i32* %e, null
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|   br i1 %cond, label %one, label %two
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| one:
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|   br label %join
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| two:
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|   br label %join
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| join:
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| 
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| ; The pointers need to be defined by PHIs in order for the bug to trigger.
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| ; Because of the PHIs the existing casts won't be at the desired location so a
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| ; new cast will be emitted and the old cast will get invalidated.
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| ;
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| ; These are the steps:
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| ;
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| ; 1. After the bounds for A and C are first expanded:
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| ;
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| ;   join:
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| ;     %a = phi i32* [ %a1, %one ], [ %a2, %two ]
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| ;     %c = phi i32* [ %c1, %one ], [ %c2, %two ]
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| ;     %c5 = bitcast i32* %c to i8*
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| ;     %a3 = bitcast i32* %a to i8*
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| ;
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| ; 2. After A is expanded again:
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| ;
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| ;   join:                                             ; preds = %two, %one
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| ;     %a = phi i32* [ %a1, %one ], [ %a2, %two ]
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| ;     %c = phi i32* [ %c1, %one ], [ %c2, %two ]
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| ;     %a3 = bitcast i32* %a to i8*                   <--- new
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| ;     %c5 = bitcast i32* %c to i8*
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| ;     %0 = bitcast i32* undef to i8*                 <--- old, invalidated
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| ;
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| ; 3. Finally, when C is expanded again:
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| ;
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| ;   join:                                             ; preds = %two, %one
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| ;     %a = phi i32* [ %a1, %one ], [ %a2, %two ]
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| ;     %c = phi i32* [ %c1, %one ], [ %c2, %two ]
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| ;     %c5 = bitcast i32* %c to i8*                   <--- new
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| ;     %a3 = bitcast i32* %a to i8*
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| ;     %0 = bitcast i32* undef to i8*                 <--- old, invalidated
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| ;     %1 = bitcast i32* undef to i8*
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| 
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|   %a = phi i32* [%a1, %one], [%a2, %two]
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|   %c = phi i32* [%c1, %one], [%c2, %two]
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|   br label %for.body
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| 
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| 
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| ; CHECK: [[VALUE:%[0-9a-z]+]] = bitcast i32* undef to i8*
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| ; CHECK-NOT: [[VALUE]]
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| 
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| for.body:                                         ; preds = %for.body, %entry
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|   %ind = phi i64 [ 0, %join ], [ %add, %for.body ]
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| 
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|   %arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
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|   %loadA = load i32, i32* %arrayidxA, align 4
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| 
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|   %arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind
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|   %loadB = load i32, i32* %arrayidxB, align 4
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| 
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|   %mulA = mul i32 %loadB, %loadA
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| 
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|   %add = add nuw nsw i64 %ind, 1
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|   %arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add
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|   store i32 %mulA, i32* %arrayidxA_plus_4, align 4
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| 
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|   %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
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|   %loadD = load i32, i32* %arrayidxD, align 4
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| 
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|   %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
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|   %loadE = load i32, i32* %arrayidxE, align 4
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| 
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|   %mulC = mul i32 %loadD, %loadE
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| 
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|   %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
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|   store i32 %mulC, i32* %arrayidxC, align 4
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| 
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|   %exitcond = icmp eq i64 %add, 20
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|   br i1 %exitcond, label %for.end, label %for.body
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| 
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| for.end:                                          ; preds = %for.body
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|   ret void
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| }
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