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