108 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			108 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: opt -basic-aa -loop-distribute -enable-loop-distribute -loop-simplify -scoped-noalias-aa \
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; RUN:     -loop-versioning -S < %s | FileCheck %s
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; Test the metadata generated when versioning an already versioned loop.  Here
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; we invoke loop distribution to perform the first round of versioning.  It
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; adds memchecks for accesses that can alias across the distribution boundary.
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; Then we further version the distributed loops to fully disambiguate accesses
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; within each.
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;
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; So as an example, we add noalias between C and A during the versioning
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; within loop distribution and then add noalias between C and D during the
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; second explicit versioning step:
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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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; To see it easier what's going on, I expanded every noalias/scope metadata
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; reference below in a comment.  For a scope I use the format scope(domain),
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; e.g. scope 17 in domain 15 is written as 17(15).
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target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
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@B = common global i32* null, align 8
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@A = common global i32* null, align 8
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@C = common global i32* null, align 8
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@D = common global i32* null, align 8
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@E = common global i32* null, align 8
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define void @f() {
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entry:
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  %a = load i32*, i32** @A, align 8
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  %b = load i32*, i32** @B, align 8
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  %c = load i32*, i32** @C, align 8
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  %d = load i32*, i32** @D, align 8
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  %e = load i32*, i32** @E, align 8
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  br label %for.body
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for.body:                                         ; preds = %for.body, %entry
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  %ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
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  %arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
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; CHECK: %loadA.ldist1 = {{.*}} !noalias !25
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; A noalias C: !25 -> { 17(15), 18(15), 19(15), 26(24) }
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;                       ^^^^^^
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  %loadA = load i32, i32* %arrayidxA, align 4
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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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  %mulA = mul i32 %loadB, %loadA
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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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; CHECK: for.body:
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  %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
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; CHECK: %loadD = {{.*}} !alias.scope !31
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; D's scope: !31 -> { 18(15), 32(33) }
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;                             ^^^^^^
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  %loadD = load i32, i32* %arrayidxD, align 4
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  %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
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; CHECK: %loadE = {{.*}} !alias.scope !34
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; E's scope: !34 -> { 19(15), 35(33) }
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;                             ^^^^^^
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  %loadE = load i32, i32* %arrayidxE, align 4
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  %mulC = mul i32 %loadD, %loadE
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  %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
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; CHECK: store i32 %mulC, {{.*}} !alias.scope !36, !noalias !38
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; C's scope: !36 -> { 17(15), 37(33) }
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;                     ^^^^^^
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; C noalias D and E: !38 -> { 21(15), 32(33), 35(33) }
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;                                     ^^^^^^  ^^^^^^
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  store i32 %mulC, i32* %arrayidxC, align 4
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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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for.end:                                          ; preds = %for.body
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  ret void
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}
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; Domain for the second loop versioning for the top loop after
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; distribution.
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; CHECK: !15 = distinct !{!15, !"LVerDomain"}
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; CHECK: !17 = distinct !{!17, !15}
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; CHECK: !25 = !{!17, !18, !19, !26}
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; CHECK: !31 = !{!18, !32}
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; CHECK: !32 = distinct !{!32, !33}
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; Domain for the second loop versioning for the bottom loop after
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; distribution.
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; CHECK: !33 = distinct !{!33, !"LVerDomain"}
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; CHECK: !34 = !{!19, !35}
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; CHECK: !35 = distinct !{!35, !33}
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; CHECK: !36 = !{!17, !37}
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; CHECK: !38 = !{!21, !32, !35}
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