[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369036 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index ef57173d468f8eb93cc8dfb611d03f5b03501aac..16bdded141eb5619c3a2801b20cefb63d4b9f04c 100644 (file)
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -481,7 +481,7 @@ bool BasicAAResult::DecomposeGEPExpression(const Value *V,
         // 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;
         }

diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 74c813ff70b3d5aef9a9ebc829931aee4e3c8e97..74293dbc973bedbff0a504a7044a682c873bf945 100644 (file)
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -3677,7 +3677,9 @@ bool llvm::isIntrinsicReturningPointerAliasingArgumentWithoutCapturing(
   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 *V, const DataLayout &DL,
         // 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;
         }

diff --git a/test/Analysis/BasicAA/ptrmask.ll b/test/Analysis/BasicAA/ptrmask.ll
new file mode 100644 (file)
index 0000000..27c14eb
--- /dev/null
+++ b/test/Analysis/BasicAA/ptrmask.ll
@@ -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)