[PATCH] D61669: [ValueTracking] Look through ptrmask intrinsics during getUnderlyingObject.

[Florian Hahn via Phabricator via llvm-commits]

fhahn updated this revision to Diff 207846.
fhahn added a comment.

Handle nonnullness requirement for the use of getArgumentAliasingToReturnedPointer
in isKnownNonZero, as suggested.

Also simplified the test.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D61669/new/

https://reviews.llvm.org/D61669

Files:
  llvm/lib/Analysis/BasicAliasAnalysis.cpp
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/test/Analysis/BasicAA/ptrmask.ll


Index: llvm/test/Analysis/BasicAA/ptrmask.ll
===================================================================
--- /dev/null
+++ llvm/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)
Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -3700,7 +3700,9 @@
 bool llvm::isIntrinsicReturningPointerAliasingArgumentWithoutCapturing(
     const CallBase *Call, bool MustPreserveNullness) {
   return Call->getIntrinsicID() == Intrinsic::launder_invariant_group ||
-         Call->getIntrinsicID() == Intrinsic::strip_invariant_group;
+         Call->getIntrinsicID() == Intrinsic::strip_invariant_group ||
+         (!MustPreserveNullness &&
+          Call->getIntrinsicID() == Intrinsic::ptrmask);
 }
 
 /// \p PN defines a loop-variant pointer to an object.  Check if the
@@ -3758,7 +3760,7 @@
         // 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;
         }
Index: llvm/lib/Analysis/BasicAliasAnalysis.cpp
===================================================================
--- llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -481,7 +481,7 @@
         // 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;
         }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D61669.207846.patch
Type: text/x-patch
Size: 3148 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190703/fe53356e/attachment.bin>