Cray pointer/pointee can alias with anything.

Author: tblah

flang/include/flang/Optimizer/Analysis/TBAAForest.h

@@ -96,7 +96,7 @@ struct TBAATree {
   //   "any access"
   //   |
   //   |- "descriptor member"
-  //   |- "any data access"
+  //   |- "any data access" <--- Cray pointer/pointee accesses
   //      |
   //      |- "dummy arg data"
   //        |

flang/lib/Optimizer/Transforms/AddAliasTags.cpp

@@ -687,9 +687,16 @@ void AddAliasTagsPass::runOnAliasInterface(fir::FirAliasTagOpInterface op,
   }
 
   mlir::LLVM::TBAATagAttr tag;
-  // TBAA for dummy arguments
-  if (enableDummyArgs &&
-      source.kind == fir::AliasAnalysis::SourceKind::Argument) {
+  // Cray pointer/pointee is a special case. These might alias with any data.
+  if (source.isCrayPointerOrPointee()) {
+    LLVM_DEBUG(llvm::dbgs().indent(2)
+               << "Found reference to Cray pointer/pointee at " << *op << "\n");
+    mlir::LLVM::TBAATypeDescriptorAttr anyDataDesc =
+        state.getFuncTreeWithScope(func, scopeOp).anyDataTypeDesc;
+    tag = mlir::LLVM::TBAATagAttr::get(anyDataDesc, anyDataDesc, /*offset=*/0);
+    // TBAA for dummy arguments
+  } else if (enableDummyArgs &&
+             source.kind == fir::AliasAnalysis::SourceKind::Argument) {
     LLVM_DEBUG(llvm::dbgs().indent(2)
                << "Found reference to dummy argument at " << *op << "\n");
     std::string name = getFuncArgName(llvm::cast<mlir::Value>(source.origin.u));

flang/test/Transforms/tbaa-cray-pointer.fir

@@ -0,0 +1,43 @@
+// RUN: fir-opt --fir-add-alias-tags %s | FileCheck %s
+
+// Fortran source:
+// subroutine test()
+//   real :: a, b
+//   pointer(p, a)
+//   p = loc(b)
+//   b = 2
+// end subroutine
+
+// CHECK:      #[[TBAA_ROOT:.*]] = #llvm.tbaa_root<id = "Flang function root _QPtest">
+// CHECK-NEXT: #[[ANY_ACCESS:.*]] = #llvm.tbaa_type_desc<id = "any access", members = {<#[[TBAA_ROOT]], 0>}>
+// CHECK-NEXT: #[[ANY_DATA:.*]] = #llvm.tbaa_type_desc<id = "any data access", members = {<#[[ANY_ACCESS]], 0>}>
+// CHECK-NEXT: #[[ANY_DATA_TAG:.*]] = #llvm.tbaa_tag<base_type = #[[ANY_DATA]], access_type = #[[ANY_DATA]], offset = 0>
+// CHECK-NEXT: #[[ALLOCATED_DATA:.*]] = #llvm.tbaa_type_desc<id = "allocated data", members = {<#[[ANY_DATA]], 0>}>
+// CHECK-NEXT: #[[B:.*]] = #llvm.tbaa_type_desc<id = "allocated data/_QFtestEb", members = {<#[[ALLOCATED_DATA]], 0>}>
+// CHECK-NEXT: #[[B_TAG:.*]] = #llvm.tbaa_tag<base_type = #[[B]], access_type = #[[B]], offset = 0>
+
+module attributes {dlti.dl_spec = #dlti.dl_spec<!llvm.ptr<270> = dense<32> : vector<4xi64>, !llvm.ptr<271> = dense<32> : vector<4xi64>, !llvm.ptr<272> = dense<64> : vector<4xi64>, i8 = dense<[8, 32]> : vector<2xi64>, i16 = dense<[16, 32]> : vector<2xi64>, i64 = dense<64> : vector<2xi64>, i128 = dense<128> : vector<2xi64>, !llvm.ptr = dense<64> : vector<4xi64>, i1 = dense<8> : vector<2xi64>, i32 = dense<32> : vector<2xi64>, f16 = dense<16> : vector<2xi64>, f64 = dense<64> : vector<2xi64>, f128 = dense<128> : vector<2xi64>, "dlti.endianness" = "little", "dlti.mangling_mode" = "e", "dlti.legal_int_widths" = array<i32: 32, 64>, "dlti.stack_alignment" = 128 : i64, "dlti.function_pointer_alignment" = #dlti.function_pointer_alignment<32, function_dependent = true>>, fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", llvm.data_layout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32"} {
+// CHECK-LABEL: func.func @_QPtest()
+  func.func @_QPtest() {
+    %cst = arith.constant 2.000000e+00 : f32
+    %0 = fir.alloca !fir.box<!fir.ptr<f32>>
+    %1 = fir.dummy_scope : !fir.dscope
+    %2 = fir.alloca i64 {bindc_name = "p", uniq_name = "_QFtestEp"}
+    %3 = fir.declare %2 {fortran_attrs = #fir.var_attrs<cray_pointer>, uniq_name = "_QFtestEp"} : (!fir.ref<i64>) -> !fir.ref<i64>
+    %4 = fir.alloca f32 {bindc_name = "b", uniq_name = "_QFtestEb"}
+    %5 = fir.declare %4 {uniq_name = "_QFtestEb"} : (!fir.ref<f32>) -> !fir.ref<f32>
+    %6 = fir.declare %0 {fortran_attrs = #fir.var_attrs<pointer, cray_pointee>, uniq_name = "_QFtestEa"} : (!fir.ref<!fir.box<!fir.ptr<f32>>>) -> !fir.ref<!fir.box<!fir.ptr<f32>>>
+    %7 = fir.zero_bits !fir.ptr<f32>
+    %8 = fir.embox %7 : (!fir.ptr<f32>) -> !fir.box<!fir.ptr<f32>>
+    fir.store %8 to %6 : !fir.ref<!fir.box<!fir.ptr<f32>>>
+// Descriptor tagged in codegen
+// CHECK: fir.store %{{.*}} to %{{.*}} : !fir.ref<!fir.box<!fir.ptr<f32>>
+    %9 = fir.convert %5 : (!fir.ref<f32>) -> i64
+    fir.store %9 to %3 : !fir.ref<i64>
+// CHECK: fir.store {{.*}} to {{.*}} {tbaa = [#[[ANY_DATA_TAG]]]} : !fir.ref<i64>
+    fir.store %cst to %5 : !fir.ref<f32>
+// CHECK: fir.store {{.*}} to {{.*}} {tbaa = [#[[B_TAG]]]} : !fir.ref<f32>
+    return
+  }
+}
+