[Attributor] Look at base values for align, nonnull, and deref

Stripping bitcasts and 0-geps helps normalization and minimizes the
impact of a follow up change.

Author: jdoerfert

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -2365,7 +2365,7 @@ struct AANonNullImpl : AANonNull {
 
   /// See AbstractAttribute::initialize(...).
   void initialize(Attributor &A) override {
-    Value &V = getAssociatedValue();
+    Value &V = *getAssociatedValue().stripPointerCasts();
     if (!NullIsDefined &&
         hasAttr({Attribute::NonNull, Attribute::Dereferenceable},
                 /* IgnoreSubsumingPositions */ false, &A)) {
@@ -2389,7 +2389,7 @@ struct AANonNullImpl : AANonNull {
       }
     }
 
-    if (isa<GlobalValue>(&getAssociatedValue())) {
+    if (isa<GlobalValue>(V)) {
       indicatePessimisticFixpoint();
       return;
     }
@@ -4217,6 +4217,7 @@ struct AADereferenceableImpl : AADereferenceable {
 
   /// See AbstractAttribute::initialize(...).
   void initialize(Attributor &A) override {
+    Value &V = *getAssociatedValue().stripPointerCasts();
     SmallVector<Attribute, 4> Attrs;
     getAttrs({Attribute::Dereferenceable, Attribute::DereferenceableOrNull},
              Attrs, /* IgnoreSubsumingPositions */ false, &A);
@@ -4227,9 +4228,8 @@ struct AADereferenceableImpl : AADereferenceable {
     NonNullAA = &A.getAAFor<AANonNull>(*this, IRP, DepClassTy::NONE);
 
     bool CanBeNull, CanBeFreed;
-    takeKnownDerefBytesMaximum(
-        IRP.getAssociatedValue().getPointerDereferenceableBytes(
-            A.getDataLayout(), CanBeNull, CanBeFreed));
+    takeKnownDerefBytesMaximum(V.getPointerDereferenceableBytes(
+        A.getDataLayout(), CanBeNull, CanBeFreed));
 
     bool IsFnInterface = IRP.isFnInterfaceKind();
     Function *FnScope = IRP.getAnchorScope();
@@ -4520,7 +4520,7 @@ struct AAAlignImpl : AAAlign {
     for (const Attribute &Attr : Attrs)
       takeKnownMaximum(Attr.getValueAsInt());
 
-    Value &V = getAssociatedValue();
+    Value &V = *getAssociatedValue().stripPointerCasts();
     takeKnownMaximum(V.getPointerAlignment(A.getDataLayout()).value());
 
     if (getIRPosition().isFnInterfaceKind() &&

llvm/test/Transforms/Attributor/value-simplify-pointer-info.ll

@@ -608,7 +608,7 @@ define void @local_alloca_simplifiable_2() {
 ; IS__CGSCC_OPM-NEXT:    br label [[FOR_COND28]], !llvm.loop [[LOOP23:![0-9]+]]
 ; IS__CGSCC_OPM:       for.end38:
 ; IS__CGSCC_OPM-NEXT:    [[I24:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 0
-; IS__CGSCC_OPM-NEXT:    call void @llvm.lifetime.end.p0i8(i64 noundef 1024, i8* nofree noundef nonnull [[I24]])
+; IS__CGSCC_OPM-NEXT:    call void @llvm.lifetime.end.p0i8(i64 noundef 1024, i8* nofree noundef nonnull align 16 dereferenceable(1024) [[I24]])
 ; IS__CGSCC_OPM-NEXT:    ret void
 ;
 ; IS__CGSCC_NPM-LABEL: define {{[^@]+}}@local_alloca_simplifiable_2() {
@@ -691,7 +691,7 @@ define void @local_alloca_simplifiable_2() {
 ; IS__CGSCC_NPM-NEXT:    br label [[FOR_COND28]], !llvm.loop [[LOOP23:![0-9]+]]
 ; IS__CGSCC_NPM:       for.end38:
 ; IS__CGSCC_NPM-NEXT:    [[I24:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 0
-; IS__CGSCC_NPM-NEXT:    call void @llvm.lifetime.end.p0i8(i64 noundef 1024, i8* nofree noundef nonnull [[I24]])
+; IS__CGSCC_NPM-NEXT:    call void @llvm.lifetime.end.p0i8(i64 noundef 1024, i8* nofree noundef nonnull align 16 dereferenceable(1024) [[I24]])
 ; IS__CGSCC_NPM-NEXT:    ret void
 ;
 entry: