49 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			49 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt -basicaa -loop-load-elim -S < %s | FileCheck %s
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| 
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| ; In this case the later store forward to the load:
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| ;
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| ;   for (unsigned i = 0; i < 100; i++) {
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| ;     B[i] = A[i] + 1;
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| ;     A[i+1] = C[i] + 2;
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| ;     A[i+1] = D[i] + 3;
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| ;   }
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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* noalias nocapture %A, i32* noalias nocapture readonly %B,
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|                i32* noalias nocapture %C, i32* noalias nocapture readonly %D,
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|                i64 %N) {
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| entry:
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| ; CHECK: %load_initial = load i32, i32* %A
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|   br label %for.body
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| 
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| for.body:                                         ; preds = %for.body, %entry
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| ; CHECK: %store_forwarded = phi i32 [ %load_initial, %entry ], [ %addD, %for.body ]
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|   %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
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|   %arrayidxA = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
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|   %loadA = load i32, i32* %arrayidxA, align 4
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| ; CHECK: %addA = add i32 %store_forwarded, 1
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|   %addA = add i32 %loadA, 1
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| 
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|   %arrayidxB = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
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|   store i32 %addA, i32* %arrayidxB, align 4
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| 
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|   %arrayidxC = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
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|   %loadC = load i32, i32* %arrayidxC, align 4
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|   %addC = add i32 %loadC, 2
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|   %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
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|   %arrayidxA_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
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|   store i32 %addC, i32* %arrayidxA_next, align 4
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| 
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|   %arrayidxD = getelementptr inbounds i32, i32* %D, i64 %indvars.iv
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|   %loadD = load i32, i32* %arrayidxD, align 4
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|   %addD = add i32 %loadD, 3
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|   store i32 %addD, i32* %arrayidxA_next, align 4
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| 
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|   %exitcond = icmp eq i64 %indvars.iv.next, %N
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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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