LAA: pre-commit tests for strip-gep

Author: artagnon

llvm/test/Analysis/LoopAccessAnalysis/symbolic-stride.ll

@@ -140,6 +140,49 @@ exit:
   ret void
 }
 
+; Test with multiple GEP indices
+define void @single_stride_array(ptr noalias %A, ptr noalias %B, i64 %N, i64 %stride) {
+; CHECK-LABEL: 'single_stride_array'
+; 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:  Unsafe indirect dependence.
+; CHECK-NEXT:      Dependences:
+; CHECK-NEXT:        IndirectUnsafe:
+; CHECK-NEXT:            %load = load [2 x i32], ptr %gep.A, align 4 ->
+; CHECK-NEXT:            store [2 x i32] %ins, ptr %gep.A.next, 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 ]
+  %mul = mul i64 %iv, %stride
+  %gep.A = getelementptr inbounds [2 x i32], ptr %A, i64 %mul, i64 1
+  %load = load [2 x i32], ptr %gep.A, align 4
+  %gep.B = getelementptr inbounds [2 x i32], ptr %B, i64 %iv
+  %load_1 = load [2 x i32], ptr %gep.B, align 4
+  %v1 = extractvalue [2 x i32] %load, 0
+  %v2 = extractvalue [2 x i32] %load_1, 0
+  %add = add i32 %v1, %v2
+  %ins = insertvalue [2 x i32] poison, i32 %add, 0
+  %iv.next = add nuw nsw i64 %iv, 1
+  %gep.A.next = getelementptr inbounds [2 x i32], ptr %A, i64 %iv.next
+  store [2 x i32] %ins, ptr %gep.A.next, align 4
+  %exitcond = icmp eq i64 %iv.next, %N
+  br i1 %exitcond, label %exit, label %loop
+
+exit:
+  ret void
+}
+
 define void @single_stride_castexpr(i32 %offset, ptr %src, ptr %dst, i1 %cond) {
 ; CHECK-LABEL: 'single_stride_castexpr'
 ; CHECK-NEXT:    inner.loop: