Index: llvm/trunk/test/Analysis/LoopAccessAnalysis/number-of-memchecks.ll =================================================================== --- llvm/trunk/test/Analysis/LoopAccessAnalysis/number-of-memchecks.ll +++ llvm/trunk/test/Analysis/LoopAccessAnalysis/number-of-memchecks.ll @@ -216,3 +216,67 @@ for.end: ; preds = %for.body ret void } + +; Don't merge pointers if there is some other check which could be falsely +; invalidated. For example, in the following loop: +; +; for (i = 0; i < 5000; ++i) +; a[i + offset] = a[i] + a[i + 10000] +; +; we should not merge the intervals associated with the reads (0,5000) and +; (10000, 15000) into (0, 15000) as this will pottentially fail the check +; against the interval associated with the write. + +; CHECK: function 'testi': +; CHECK: Run-time memory checks: +; CHECK-NEXT: Check 0: +; CHECK-NEXT: Comparing group 0: +; CHECK-NEXT: %storeidx = getelementptr inbounds i16, i16* %a, i64 %store_ind +; CHECK-NEXT: Against group 1: +; CHECK-NEXT: %arrayidxA1 = getelementptr i16, i16* %a, i64 %ind +; CHECK-NEXT: Check 1: +; CHECK-NEXT: Comparing group 0: +; CHECK-NEXT: %storeidx = getelementptr inbounds i16, i16* %a, i64 %store_ind +; CHECK-NEXT: Against group 2: +; CHECK-NEXT: %arrayidxA2 = getelementptr i16, i16* %a, i64 %ind2 +; CHECK-NEXT: Grouped accesses: +; CHECK-NEXT: Group 0: +; CHECK-NEXT: (Low: ((2 * %offset) + %a) High: (9998 + (2 * %offset) + %a)) +; CHECK-NEXT: Member: {((2 * %offset) + %a),+,2}<%for.body> +; CHECK-NEXT: Group 1: +; CHECK-NEXT: (Low: %a High: (9998 + %a)) +; CHECK-NEXT: Member: {%a,+,2}<%for.body> +; CHECK-NEXT: Group 2: +; CHECK-NEXT: (Low: (20000 + %a) High: (29998 + %a)) +; CHECK-NEXT: Member: {(20000 + %a),+,2}<%for.body> + +define void @testi(i16* %a, + i64 %offset) { +entry: + br label %for.body + +for.body: ; preds = %for.body, %entry + %ind = phi i64 [ 0, %entry ], [ %add, %for.body ] + %store_ind = phi i64 [ %offset, %entry ], [ %store_ind_inc, %for.body ] + + %add = add nuw nsw i64 %ind, 1 + %store_ind_inc = add nuw nsw i64 %store_ind, 1 + + %arrayidxA1 = getelementptr i16, i16* %a, i64 %ind + %ind2 = add nuw nsw i64 %ind, 10000 + %arrayidxA2 = getelementptr i16, i16* %a, i64 %ind2 + + %loadA1 = load i16, i16* %arrayidxA1, align 2 + %loadA2 = load i16, i16* %arrayidxA2, align 2 + + %addres = add i16 %loadA1, %loadA2 + + %storeidx = getelementptr inbounds i16, i16* %a, i64 %store_ind + store i16 %addres, i16* %storeidx, align 2 + + %exitcond = icmp eq i64 %add, 5000 + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body + ret void +}