[llvm] r369036 - [ValueTracking] Look through ptrmask intrinsics during getUnderlyingObject.

[Florian Hahn via llvm-commits]

Author: fhahn
Date: Thu Aug 15 11:39:56 2019
New Revision: 369036

URL: http://llvm.org/viewvc/llvm-project?rev=369036&view=rev
Log:
[ValueTracking] Look through ptrmask intrinsics during getUnderlyingObject.

Reviewers: nlopes, efriedma, hfinkel, sanjoy, aqjune, jdoerfert

Reviewed By: jdoerfert

Subscribers: jdoerfert, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61669

Added:
    llvm/trunk/test/Analysis/BasicAA/ptrmask.ll
Modified:
    llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
    llvm/trunk/lib/Analysis/ValueTracking.cpp

Modified: llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp?rev=369036&r1=369035&r2=369036&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp Thu Aug 15 11:39:56 2019
@@ -481,7 +481,7 @@ bool BasicAAResult::DecomposeGEPExpressi
         // because it should be in sync with CaptureTracking. Not using it may
         // cause weird miscompilations where 2 aliasing pointers are assumed to
         // noalias.
-        if (auto *RP = getArgumentAliasingToReturnedPointer(Call, true)) {
+        if (auto *RP = getArgumentAliasingToReturnedPointer(Call, false)) {
           V = RP;
           continue;
         }

Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=369036&r1=369035&r2=369036&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Thu Aug 15 11:39:56 2019
@@ -3677,7 +3677,9 @@ bool llvm::isIntrinsicReturningPointerAl
   return Call->getIntrinsicID() == Intrinsic::launder_invariant_group ||
          Call->getIntrinsicID() == Intrinsic::strip_invariant_group ||
          Call->getIntrinsicID() == Intrinsic::aarch64_irg ||
-         Call->getIntrinsicID() == Intrinsic::aarch64_tagp;
+         Call->getIntrinsicID() == Intrinsic::aarch64_tagp ||
+         (!MustPreserveNullness &&
+          Call->getIntrinsicID() == Intrinsic::ptrmask);
 }
 
 /// \p PN defines a loop-variant pointer to an object.  Check if the
@@ -3735,7 +3737,7 @@ Value *llvm::GetUnderlyingObject(Value *
         // because it should be in sync with CaptureTracking. Not using it may
         // cause weird miscompilations where 2 aliasing pointers are assumed to
         // noalias.
-        if (auto *RP = getArgumentAliasingToReturnedPointer(Call, true)) {
+        if (auto *RP = getArgumentAliasingToReturnedPointer(Call, false)) {
           V = RP;
           continue;
         }

Added: llvm/trunk/test/Analysis/BasicAA/ptrmask.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/BasicAA/ptrmask.ll?rev=369036&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/BasicAA/ptrmask.ll (added)
+++ llvm/trunk/test/Analysis/BasicAA/ptrmask.ll Thu Aug 15 11:39:56 2019
@@ -0,0 +1,29 @@
+; RUN: opt -basicaa -aa-eval -print-no-aliases -disable-output %s 2>&1 | FileCheck %s
+
+%struct = type <{ [20 x i64] }>
+
+; CHECK-LABEL: Function: test_noalias: 4 pointers, 1 call sites
+; CHECK-NEXT:  NoAlias:	%struct* %ptr1, i64* %ptr2
+; CHECK-NEXT:  NoAlias:	%struct* %addr.ptr, i64* %ptr2
+; CHECK-NEXT:  NoAlias:	i64* %gep, i64* %ptr2
+define void @test_noalias(%struct* noalias %ptr1, i64* %ptr2, i64 %offset) {
+entry:
+  %addr.ptr = call %struct* @llvm.ptrmask.p0s_struct.p0s.struct.i64(%struct* %ptr1, i64 72057594037927928)
+  store i64 10, i64* %ptr2
+  %gep = getelementptr inbounds %struct, %struct* %addr.ptr, i64 0, i32 0, i64 %offset
+  store i64 1, i64* %gep, align 8
+  ret void
+}
+
+; CHECK-NEXT: Function: test_alias: 4 pointers, 1 call sites
+; CHECK-NOT: NoAlias
+define void @test_alias(%struct* %ptr1, i64* %ptr2, i64 %offset) {
+entry:
+  %addr.ptr = call %struct* @llvm.ptrmask.p0s_struct.p0s.struct.i64(%struct* %ptr1, i64 72057594037927928)
+  store i64 10, i64* %ptr2
+  %gep = getelementptr inbounds %struct, %struct* %addr.ptr, i64 0, i32 0, i64 %offset
+  store i64 1, i64* %gep, align 8
+  ret void
+}
+
+declare %struct* @llvm.ptrmask.p0s_struct.p0s.struct.i64(%struct*, i64)