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[LAA] Precommit test with loops where indices are loaded in each iter.
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Add tests which are not safe to vectorize because %indices are loaded in
the loop and the same indices could be loaded in later iterations.

Tests for llvm#87189.
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fhahn authored and aaryanshukla committed Jul 14, 2024
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; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5
; RUN: opt -passes='print<access-info>' -disable-output %s 2>&1 | FileCheck %s

; Test case for https://github.com/llvm/llvm-project/issues/87189.
; It is not safe to vectorize because %indices are loaded in the loop and the
; same indices could be loaded in later iterations.
; FIXME: currently this is incorrectly considered safe for vectorization with
; runtime checks
define void @B_indices_loaded_in_loop_A_stored(ptr %A, ptr noalias %B, i64 %N) {
; CHECK-LABEL: 'B_indices_loaded_in_loop_A_stored'
; CHECK-NEXT: loop:
; CHECK-NEXT: Memory dependences are safe with run-time checks
; CHECK-NEXT: Dependences:
; CHECK-NEXT: Run-time memory checks:
; CHECK-NEXT: Check 0:
; CHECK-NEXT: Comparing group ([[GRP1:0x[0-9a-f]+]]):
; CHECK-NEXT: %gep.A.1 = getelementptr inbounds i32, ptr %A, i64 %iv
; CHECK-NEXT: Against group ([[GRP2:0x[0-9a-f]+]]):
; CHECK-NEXT: %gep.A.0 = getelementptr inbounds i8, ptr %A, i64 %iv
; CHECK-NEXT: Grouped accesses:
; CHECK-NEXT: Group [[GRP1]]:
; CHECK-NEXT: (Low: %A High: ((4 * %N) + %A))
; CHECK-NEXT: Member: {%A,+,4}<nuw><%loop>
; CHECK-NEXT: Group [[GRP2]]:
; CHECK-NEXT: (Low: %A High: (%N + %A))
; CHECK-NEXT: Member: {%A,+,1}<nuw><%loop>
; CHECK-EMPTY:
; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop.
; CHECK-NEXT: SCEV assumptions:
; CHECK-EMPTY:
; CHECK-NEXT: Expressions re-written:
;
entry:
br label %loop

loop:
%iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
%gep.A.0 = getelementptr inbounds i8, ptr %A, i64 %iv
%indices = load i8, ptr %gep.A.0, align 1
%indices.ext = zext i8 %indices to i64
%gep.B = getelementptr inbounds i32, ptr %B, i64 %indices.ext
%l = load i32, ptr %gep.B, align 4
%inc = add i32 %l, 1
store i32 %inc, ptr %gep.B, align 4
%gep.A.1 = getelementptr inbounds i32, ptr %A, i64 %iv
store i32 %l, ptr %gep.A.1, align 4
%iv.next = add nuw nsw i64 %iv, 1
%ec = icmp eq i64 %iv.next, %N
br i1 %ec, label %exit, label %loop

exit:
ret void
}

; It is not safe to vectorize because %indices are loaded in the loop and the
; same indices could be loaded in later iterations.
define void @B_indices_loaded_in_loop_A_not_stored(ptr %A, ptr noalias %B, i64 %N) {
; CHECK-LABEL: 'B_indices_loaded_in_loop_A_not_stored'
; CHECK-NEXT: loop:
; CHECK-NEXT: Report: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop
; CHECK-NEXT: Unknown data dependence.
; CHECK-NEXT: Dependences:
; CHECK-NEXT: Unknown:
; CHECK-NEXT: %l = load i32, ptr %gep.B, align 4 ->
; CHECK-NEXT: store i32 %inc, ptr %gep.B, align 4
; CHECK-EMPTY:
; CHECK-NEXT: Run-time memory checks:
; CHECK-NEXT: Grouped accesses:
; CHECK-EMPTY:
; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop.
; CHECK-NEXT: SCEV assumptions:
; CHECK-EMPTY:
; CHECK-NEXT: Expressions re-written:
;
entry:
br label %loop

loop:
%iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
%gep.A.0 = getelementptr inbounds i8, ptr %A, i64 %iv
%indices = load i8, ptr %gep.A.0, align 1
%indices.ext = zext i8 %indices to i64
%gep.B = getelementptr inbounds i32, ptr %B, i64 %indices.ext
%l = load i32, ptr %gep.B, align 4
%inc = add i32 %l, 1
store i32 %inc, ptr %gep.B, align 4
%iv.next = add nuw nsw i64 %iv, 1
%ec = icmp eq i64 %iv.next, %N
br i1 %ec, label %exit, label %loop

exit:
ret void
}

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