Fix case of allocatable arg

The address in it should be a `SourceKind::Direct` not a
`SourceKind::Argument`.  The fix is to set `SourceKind::Direct` in the
case of `!fir.heap` besides just pointers.

An effect is that the address *in* it cannot alias the address *of*
it.  flang/test/Analysis/AliasAnalysis/alias-analysis-8.fir expects
the same relationship in the case of allocatable globals.

Extend AddAliasTags to handle the case of `SourceKind::Direct` for an
arg, and update the occurrence in flang/test/Transforms/tbaa2.fir.

Author: jdenny-ornl

flang/lib/Optimizer/Analysis/AliasAnalysis.cpp

@@ -412,7 +412,7 @@ AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v) {
         attributes.set(Attribute::Target);
       if (Source::isPointerReference(ty))
         attributes.set(Attribute::Pointer);
-      if (followBoxAddr && attributes.test(Attribute::Pointer))
+      if (followBoxAddr && fir::isa_ref_type(ty))
         type = SourceKind::Direct;
       else
         type = SourceKind::Argument;

flang/lib/Optimizer/Transforms/AddAliasTags.cpp

@@ -171,10 +171,28 @@ void AddAliasTagsPass::runOnAliasInterface(fir::FirAliasTagOpInterface op,
                                         << " at " << *op << "\n");
       tag = state.getFuncTree(func).directDataTree.getTag(name);
     } else {
-      // SourceKind::Direct is likely to be extended to cases which are not a
-      // SymbolRefAttr in the future
-      LLVM_DEBUG(llvm::dbgs().indent(2) << "Can't get name for direct "
-                                        << source << " at " << *op << "\n");
+      bool sourceIsDummyArgument = false;
+      if (auto blockArg =
+              source.u.get<mlir::Value>().dyn_cast<mlir::BlockArgument>())
+        sourceIsDummyArgument = blockArg.getOwner()->isEntryBlock();
+      if (sourceIsDummyArgument) {
+        std::string name = getFuncArgName(source.u.get<mlir::Value>());
+        if (!name.empty()) {
+          LLVM_DEBUG(llvm::dbgs().indent(2)
+                     << "Found reference to direct from dummy argument " << name
+                     << " at " << *op << "\n");
+          tag = state.getFuncTree(func).directDataTree.getTag(name);
+        } else {
+          LLVM_DEBUG(llvm::dbgs().indent(2)
+                     << "WARN: for direct, couldn't find a name for dummy "
+                     << "argument " << *op << "\n");
+        }
+      } else {
+        // SourceKind::Direct is likely to be extended to more cases in the
+        // future
+        LLVM_DEBUG(llvm::dbgs().indent(2) << "Can't get name for direct "
+                                          << source << " at " << *op << "\n");
+      }
     }
 
     // TBAA for local allocations

flang/test/Analysis/AliasAnalysis/alias-analysis-box-addr-load/arg.fir

@@ -4,7 +4,7 @@
 // as well as its diagnostic output.
 // RUN: fir-opt %s \
 // RUN:   -pass-pipeline='builtin.module(func.func(test-fir-alias-analysis))' \
-// RUN:   --mlir-disable-threading 2>&1 | FileCheck %s
+// RUN:   --mlir-disable-threading 2>&1 | FileCheck -match-full-lines %s
 
 // subroutine test(p0, p1, arr, t_arr, alloc, t_alloc)
 //   real, pointer :: p0, p1
@@ -51,8 +51,12 @@
 // CHECK-DAG: p0.tgt_addr#0 <-> alloc.tgt_addr#0: NoAlias
 // CHECK-DAG: p0.tgt_addr#0 <-> t_alloc.tgt_addr#0: MayAlias
 
+// The address *in* an allocatable cannot alias the address *of* that
+// allocatable.
+// CHECK-DAG: alloc#0 <-> alloc.tgt_addr#0: NoAlias
+
 func.func @_QPtest(%arg0: !fir.ref<!fir.box<!fir.ptr<f32>>> {fir.bindc_name = "p0"}, %arg1: !fir.ref<!fir.box<!fir.ptr<f32>>> {fir.bindc_name = "p1"}, %arg2: !fir.box<!fir.array<?xf32>> {fir.bindc_name = "arr"}, %arg3: !fir.box<!fir.array<?xf32>> {fir.bindc_name = "t_arr", fir.target}, %arg4: !fir.ref<!fir.box<!fir.heap<f32>>> {fir.bindc_name = "alloc"}, %arg5: !fir.ref<!fir.box<!fir.heap<f32>>> {fir.bindc_name = "t_alloc", fir.target}) attributes {test.ptr="func"} {
-  %0:2 = hlfir.declare %arg4 {fortran_attrs = #fir.var_attrs<allocatable>, uniq_name = "_QFtestEalloc"} : (!fir.ref<!fir.box<!fir.heap<f32>>>) -> (!fir.ref<!fir.box<!fir.heap<f32>>>, !fir.ref<!fir.box<!fir.heap<f32>>>)
+  %0:2 = hlfir.declare %arg4 {fortran_attrs = #fir.var_attrs<allocatable>, uniq_name = "_QFtestEalloc", test.ptr="alloc"} : (!fir.ref<!fir.box<!fir.heap<f32>>>) -> (!fir.ref<!fir.box<!fir.heap<f32>>>, !fir.ref<!fir.box<!fir.heap<f32>>>)
   %1:2 = hlfir.declare %arg2 {uniq_name = "_QFtestEarr"} : (!fir.box<!fir.array<?xf32>>) -> (!fir.box<!fir.array<?xf32>>, !fir.box<!fir.array<?xf32>>)
   %2:2 = hlfir.declare %arg0 {fortran_attrs = #fir.var_attrs<pointer>, uniq_name = "_QFtestEp0"} : (!fir.ref<!fir.box<!fir.ptr<f32>>>) -> (!fir.ref<!fir.box<!fir.ptr<f32>>>, !fir.ref<!fir.box<!fir.ptr<f32>>>)
   %3:2 = hlfir.declare %arg1 {fortran_attrs = #fir.var_attrs<pointer>, uniq_name = "_QFtestEp1"} : (!fir.ref<!fir.box<!fir.ptr<f32>>>) -> (!fir.ref<!fir.box<!fir.ptr<f32>>>, !fir.ref<!fir.box<!fir.ptr<f32>>>)

flang/test/Transforms/tbaa2.fir

@@ -48,14 +48,14 @@
 // CHECK: #[[ANY_ACCESS:.+]] = #llvm.tbaa_type_desc<id = "any access", members = {<#[[ROOT]], 0>}>
 // CHECK: #[[ANY_DATA:.+]] = #llvm.tbaa_type_desc<id = "any data access", members = {<#[[ANY_ACCESS]], 0>}>
 // CHECK: #[[ANY_GLBL:.+]] = #llvm.tbaa_type_desc<id = "global data", members = {<#[[ANY_DATA]], 0>}>
-// CHECK: #[[ANY_ARG:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data", members = {<#[[ANY_DATA]], 0>}>
 // CHECK: #[[ANY_DIRECT:.+]] = #llvm.tbaa_type_desc<id = "direct data", members = {<#[[ANY_DATA]], 0>}>
+// CHECK: #[[ANY_ARG:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data", members = {<#[[ANY_DATA]], 0>}>
 // CHECK: #[[GLBL_ZSTART:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEzstart", members = {<#[[ANY_GLBL]], 0>}>
 // CHECK: #[[GLBL_ZSTOP:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEzstop", members = {<#[[ANY_GLBL]], 0>}>
 // CHECK: #[[GLBL_YSTART:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEystart", members = {<#[[ANY_GLBL]], 0>}>
 // CHECK: #[[GLBL_YSTOP:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodEystop", members = {<#[[ANY_GLBL]], 0>}>
 // CHECK: #[[GLBL_XSTART:.+]] = #llvm.tbaa_type_desc<id = "global data/_QMmodExstart", members = {<#[[ANY_GLBL]], 0>}>
-// CHECK: #[[ARG_LOW:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data/_QMmodFcalleeElow", members = {<#[[ANY_ARG]], 0>}>
+// CHECK: #[[ARG_LOW:.+]] = #llvm.tbaa_type_desc<id = "direct data/_QMmodFcalleeElow", members = {<#[[ANY_DIRECT]], 0>}>
 // CHECK: #[[DIRECT_A:.+]] = #llvm.tbaa_type_desc<id = "direct data/_QMmodEa", members = {<#[[ANY_DIRECT]], 0>}>
 // CHECK: #[[DIRECT_B:.+]] = #llvm.tbaa_type_desc<id = "direct data/_QMmodEb", members = {<#[[ANY_DIRECT]], 0>}>
 // CHECK: #[[ARG_Z:.+]] = #llvm.tbaa_type_desc<id = "dummy arg data/_QMmodFcalleeEz", members = {<#[[ANY_ARG]], 0>}>