[llvm] f17b9dd - [LVI] Handle nonnull attributes at callsite (#125377)

[via llvm-commits]

Author: Yingwei Zheng
Date: 2025-02-03T10:22:38+08:00
New Revision: f17b9dde7a1a752ea31766aad169ea2f51558edb

URL: https://github.com/llvm/llvm-project/commit/f17b9dde7a1a752ea31766aad169ea2f51558edb
DIFF: https://github.com/llvm/llvm-project/commit/f17b9dde7a1a752ea31766aad169ea2f51558edb.diff

LOG: [LVI] Handle nonnull attributes at callsite (#125377)

This patch is the followup of
https://github.com/llvm/llvm-project/pull/124908.

Added: 
    

Modified: 
    llvm/lib/Analysis/LazyValueInfo.cpp
    llvm/test/Transforms/CorrelatedValuePropagation/non-null.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index f588d8f7e7b1095..5cd179df436de61 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -624,10 +624,12 @@ LazyValueInfoImpl::solveBlockValueImpl(Value *Val, BasicBlock *BB) {
   return getFromRangeMetadata(BBI);
 }
 
-static void AddNonNullPointer(Value *Ptr, NonNullPointerSet &PtrSet) {
+static void AddNonNullPointer(Value *Ptr, NonNullPointerSet &PtrSet,
+                              bool IsDereferenced = true) {
   // TODO: Use NullPointerIsDefined instead.
   if (Ptr->getType()->getPointerAddressSpace() == 0)
-    PtrSet.insert(getUnderlyingObject(Ptr));
+    PtrSet.insert(IsDereferenced ? getUnderlyingObject(Ptr)
+                                 : Ptr->stripInBoundsOffsets());
 }
 
 static void AddNonNullPointersByInstruction(
@@ -646,6 +648,13 @@ static void AddNonNullPointersByInstruction(
     AddNonNullPointer(MI->getRawDest(), PtrSet);
     if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI))
       AddNonNullPointer(MTI->getRawSource(), PtrSet);
+  } else if (auto *CB = dyn_cast<CallBase>(I)) {
+    for (auto &U : CB->args()) {
+      if (U->getType()->isPointerTy() &&
+          CB->paramHasNonNullAttr(CB->getArgOperandNo(&U),
+                                  /*AllowUndefOrPoison=*/false))
+        AddNonNullPointer(U.get(), PtrSet, /*IsDereferenced=*/false);
+    }
   }
 }
 

diff  --git a/llvm/test/Transforms/CorrelatedValuePropagation/non-null.ll b/llvm/test/Transforms/CorrelatedValuePropagation/non-null.ll
index 35d866ed2d92ebf..53a94e13a1763c2 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/non-null.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/non-null.ll
@@ -344,4 +344,105 @@ define i1 @test_store_same_block(ptr %arg) {
   ret i1 %cmp
 }
 
+
+define i1 @test_known_nonnull_at_callsite(ptr %src) {
+; CHECK-LABEL: @test_known_nonnull_at_callsite(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void @callee(ptr noundef nonnull [[SRC:%.*]])
+; CHECK-NEXT:    [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  call void @callee(ptr noundef nonnull %src)
+  %nonnull = icmp eq ptr %src, null
+  ret i1 %nonnull
+}
+
+define i1 @test_known_nonnull_mixed(ptr %src) {
+; CHECK-LABEL: @test_known_nonnull_mixed(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void @callee2(ptr nonnull [[SRC:%.*]])
+; CHECK-NEXT:    [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  call void @callee2(ptr nonnull %src)
+  %nonnull = icmp eq ptr %src, null
+  ret i1 %nonnull
+}
+
+define i1 @test_known_nonnull_at_callsite_dereferenceable(ptr %src) {
+; CHECK-LABEL: @test_known_nonnull_at_callsite_dereferenceable(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void @callee(ptr dereferenceable(1) [[SRC:%.*]])
+; CHECK-NEXT:    [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  call void @callee(ptr dereferenceable(1) %src)
+  %nonnull = icmp eq ptr %src, null
+  ret i1 %nonnull
+}
+
+define i1 @test_known_nonnull_at_callsite_gep_inbounds(ptr %src, i64 %x) {
+; CHECK-LABEL: @test_known_nonnull_at_callsite_gep_inbounds(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, ptr [[SRC:%.*]], i64 [[X:%.*]]
+; CHECK-NEXT:    call void @callee(ptr noundef nonnull [[GEP]])
+; CHECK-NEXT:    [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  %gep = getelementptr inbounds i8, ptr %src, i64 %x
+  call void @callee(ptr noundef nonnull %gep)
+  %nonnull = icmp eq ptr %src, null
+  ret i1 %nonnull
+}
+
+; Negative tests
+
+define i1 @test_known_nonnull_at_callsite_without_noundef(ptr %src) {
+; CHECK-LABEL: @test_known_nonnull_at_callsite_without_noundef(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void @callee(ptr nonnull [[SRC:%.*]])
+; CHECK-NEXT:    [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
+; CHECK-NEXT:    ret i1 [[NONNULL]]
+;
+entry:
+  call void @callee(ptr nonnull %src)
+  %nonnull = icmp eq ptr %src, null
+  ret i1 %nonnull
+}
+
+define i1 @test_known_nonnull_at_callsite_dereferenceable_null_is_defined(ptr %src) #0 {
+; CHECK-LABEL: @test_known_nonnull_at_callsite_dereferenceable_null_is_defined(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void @callee(ptr dereferenceable(1) [[SRC:%.*]])
+; CHECK-NEXT:    [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
+; CHECK-NEXT:    ret i1 [[NONNULL]]
+;
+entry:
+  call void @callee(ptr dereferenceable(1) %src)
+  %nonnull = icmp eq ptr %src, null
+  ret i1 %nonnull
+}
+
+define i1 @test_known_nonnull_at_callsite_gep_without_inbounds(ptr %src, i64 %x) {
+; CHECK-LABEL: @test_known_nonnull_at_callsite_gep_without_inbounds(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i8, ptr [[SRC:%.*]], i64 [[X:%.*]]
+; CHECK-NEXT:    call void @callee(ptr noundef nonnull [[GEP]])
+; CHECK-NEXT:    [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
+; CHECK-NEXT:    ret i1 [[NONNULL]]
+;
+entry:
+  %gep = getelementptr i8, ptr %src, i64 %x
+  call void @callee(ptr noundef nonnull %gep)
+  %nonnull = icmp eq ptr %src, null
+  ret i1 %nonnull
+}
+
+declare void @callee(ptr)
+declare void @callee2(ptr noundef)
+
 attributes #0 = { null_pointer_is_valid }