vendor/llvm/llvm-trunk-r366426

1 files changed, 9 insertions, 6 deletions

diff --git a/lib/Analysis/Lint.cpp b/lib/Analysis/Lint.cpp
index 5d0a627f8426..d28b8a189d4b 100644
--- a/lib/Analysis/Lint.cpp
+++ b/lib/Analysis/Lint.cpp
@@ -1,9 +1,8 @@
 //===-- Lint.cpp - Check for common errors in LLVM IR ---------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -268,10 +267,14 @@ void Lint::visitCallSite(CallSite CS) {
         if (Formal->hasNoAliasAttr() && Actual->getType()->isPointerTy()) {
           AttributeList PAL = CS.getAttributes();
           unsigned ArgNo = 0;
-          for (CallSite::arg_iterator BI = CS.arg_begin(); BI != AE; ++BI) {
+          for (CallSite::arg_iterator BI = CS.arg_begin(); BI != AE;
+               ++BI, ++ArgNo) {
             // Skip ByVal arguments since they will be memcpy'd to the callee's
             // stack so we're not really passing the pointer anyway.
-            if (PAL.hasParamAttribute(ArgNo++, Attribute::ByVal))
+            if (PAL.hasParamAttribute(ArgNo, Attribute::ByVal))
+              continue;
+            // If both arguments are readonly, they have no dependence.
+            if (Formal->onlyReadsMemory() && CS.onlyReadsMemory(ArgNo))
               continue;
             if (AI != BI && (*BI)->getType()->isPointerTy()) {
               AliasResult Result = AA->alias(*AI, *BI);