[flang] support (hl)fir.declare in alias analysis

[Renaud-K]

flang/test/Analysis/AliasAnalysis/alias-analysis-2.fir

257

Thank you for doing this.
I am not sure its a good idea to do more testing on box_addr when it is not something that we follow. I know I am guilty of adding a few tests with it but some have FIXMEs. It looks like we are going to have a lot more to fix and review when we do follow it. A fir.convert, instead of %6 and %13, should be good enough to cover the change.

[tblah]

Thanks for taking a look. I've updated the patch not to use fir.box_addr.

[tblah]

adding missing dependency on HLFIRDialect

flang/lib/Optimizer/Analysis/AliasAnalysis.cpp

 //===- AliasAnalysis.cpp - Alias Analysis for FIR  ------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "flang/Optimizer/Analysis/AliasAnalysis.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIROpsSupport.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
+#include "flang/Optimizer/HLFIR/HLFIROps.h"
 #include "mlir/Analysis/AliasAnalysis.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/Value.h"
 #include "mlir/Interfaces/SideEffectInterfaces.h"
 #include "llvm/ADT/TypeSwitch.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Debug.h"
 
llvm::TypeSwitch<Operation *>(defOp)
                                         fir::GlobalOp::getTargetAttrNameStr()))
             attributes.set(Attribute::Target);
 
           if (Source::isPointerReference(ty))
             attributes.set(Attribute::Pointer);
           global = llvm::cast<fir::AddrOfOp>(op).getSymbol();
           breakFromLoop = true;
         })
+        .Case<hlfir::DeclareOp, fir::DeclareOp>([&](auto op) {
+          // Track further through the operand
+          v = op.getMemref();
+          defOp = v.getDefiningOp();
+        })
         .Default([&](auto op) {
           defOp = nullptr;
           breakFromLoop = true;
         });
   }
   if (!defOp && type == SourceKind::Unknown)
     // Check if the memory source is coming through a dummy argument.
     if (isDummyArgument(v)) {

flang/lib/Optimizer/Analysis/CMakeLists.txt

 add_flang_library(FIRAnalysis
   AliasAnalysis.cpp
 
   DEPENDS
   FIRDialect
   MLIRIR
 
   LINK_LIBS
   FIRBuilder
   FIRDialect
+  HLFIRDialect
   MLIRFuncDialect
   MLIRLLVMDialect
   MLIRMathTransforms
   FIRSupport
 )

flang/test/Analysis/AliasAnalysis/alias-analysis-2.fir

 
 func.func @_QFPtest3(%arg0: !fir.ref<!fir.box<!fir.ptr<f32>>> {fir.bindc_name = "p1"}, %arg1: !fir.ref<f32>) attributes {test.ptr = "func"} {
   %4 = fir.address_of(@_QFEvar2) {test.ptr = "var2"} : !fir.ref<f32>
   %5 = fir.address_of(@_QMpointersEp) {test.ptr = "p"} : !fir.ref<!fir.box<!fir.ptr<f32>>>
   %6 = fir.embox %4 : (!fir.ref<f32>) -> !fir.box<!fir.ptr<f32>>
   %13 = fir.box_addr %6 {test.ptr = "box.addr"} : (!fir.box<!fir.ptr<f32>>) -> !fir.ptr<f32>
   return
 }
+
+// -----
+
+// CHECK-LABEL: Testing : "_QFPtest4"
+
+// Same as test3 but check that the alias analysis can follow (hl)fir.declare
+// operations
+
+// CHECK-DAG: p#0 <-> func.region0#0: MayAlias
+// CHECK-DAG: p_fir#0 <-> func.region0#0: MayAlias
+// CHECK-DAG: p_hlfir#0 <-> func.region0#0: MayAlias
+// CHECK-DAG: p_hlfir#1 <-> func.region0#0: MayAlias
+
+// CHECK-DAG: p#0 <-> func.region0#1: NoAlias
+// CHECK-DAG: p_fir#0 <-> func.region0#1: NoAlias
+// CHECK-DAG: p_hlfir#0 <-> func.region0#1: NoAlias
+// CHECK-DAG: p_hlfir#1 <-> func.region0#1: NoAlias
+
+// CHECK-DAG: var2#0 <-> p#0: NoAlias
+// CHECK-DAG: var2#0 <-> p_fir#0: NoAlias
+// CHECK-DAG: var2#0 <-> p_hlfir#0: NoAlias
+// CHECK-DAG: var2#0 <-> p_hlfir#1: NoAlias
+// CHECK-DAG: var2_fir#0 <-> p#0: NoAlias
+// CHECK-DAG: var2_fir#0 <-> p_fir#0: NoAlias
+// CHECK-DAG: var2_fir#0 <-> p_hlfir#0: NoAlias
+// CHECK-DAG: var2_fir#0 <-> p_hlfir#1: NoAlias
+// CHECK-DAG: var2_hlfir#0 <-> p#0: NoAlias
+// CHECK-DAG: var2_hlfir#0 <-> p_fir#0: NoAlias
+// CHECK-DAG: var2_hlfir#0 <-> p_hlfir#0: NoAlias
+// CHECK-DAG: var2_hlfir#0 <-> p_hlfir#1: NoAlias
+// CHECK-DAG: var2_hlfir#1 <-> p#0: NoAlias
+// CHECK-DAG: var2_hlfir#1 <-> p_fir#0: NoAlias
+// CHECK-DAG: var2_hlfir#1 <-> p_hlfir#0: NoAlias
+// CHECK-DAG: var2_hlfir#1 <-> p_hlfir#1: NoAlias
+
+// CHECK-DAG: var2#0 <-> func.region0#0: MayAlias
+// CHECK-DAG: var2_fir#0 <-> func.region0#0: MayAlias
+// CHECK-DAG: var2_hlfir#0 <-> func.region0#0: MayAlias
+// CHECK-DAG: var2_hlfir#1 <-> func.region0#0: MayAlias
+
+// CHECK-DAG: var2#0 <-> box.addr#0: MustAlias
+// CHECK-DAG: var2#0 <-> box.addr_fir#0: MustAlias
+// CHECK-DAG: var2#0 <-> box.addr_hlfir#0: MustAlias
+// CHECK-DAG: var2#0 <-> box.addr_hlfir#1: MustAlias
+// CHECK-DAG: var2_fir#0 <-> box.addr#0: MustAlias
+// CHECK-DAG: var2_fir#0 <-> box.addr_fir#0: MustAlias
+// CHECK-DAG: var2_fir#0 <-> box.addr_hlfir#0: MustAlias
+// CHECK-DAG: var2_fir#0 <-> box.addr_hlfir#1: MustAlias
+// CHECK-DAG: var2_hlfir#0 <-> box.addr#0: MustAlias
+// CHECK-DAG: var2_hlfir#0 <-> box.addr_fir#0: MustAlias
+// CHECK-DAG: var2_hlfir#0 <-> box.addr_hlfir#0: MustAlias
+// CHECK-DAG: var2_hlfir#0 <-> box.addr_hlfir#1: MustAlias
+// CHECK-DAG: var2_hlfir#1 <-> box.addr#0: MustAlias
+// CHECK-DAG: var2_hlfir#1 <-> box.addr_fir#0: MustAlias
+// CHECK-DAG: var2_hlfir#1 <-> box.addr_hlfir#0: MustAlias
+// CHECK-DAG: var2_hlfir#1 <-> box.addr_hlfir#1: MustAlias
+
+// CHECK-DAG: var2#0 <-> func.region0#1: NoAlias
+// CHECK-DAG: var2_fir#0 <-> func.region0#1: NoAlias
+// CHECK-DAG: var2_hlfir#0 <-> func.region0#1: NoAlias
+// CHECK-DAG: var2_hlfir#1 <-> func.region0#1: NoAlias
+
+// CHECK-DAG: func.region0#0 <-> func.region0#1: NoAlias
+
+fir.global @_QMpointersEp : !fir.box<!fir.ptr<f32>> {
+  %0 = fir.zero_bits !fir.ptr<f32>
+  %1 = fir.embox %0 : (!fir.ptr<f32>) -> !fir.box<!fir.ptr<f32>>
+  fir.has_value %1 : !fir.box<!fir.ptr<f32>>
+}
+
+fir.global internal @_QFEvar2 target : f32 {
+  %cst = arith.constant 2.000000e+00 : f32
+  fir.has_value %cst : f32
+}
+
+func.func @_QFPtest4(%arg0: !fir.ref<!fir.box<!fir.ptr<f32>>> {fir.bindc_name = "p1"}, %arg1: !fir.ref<f32>) attributes {test.ptr = "func"} {
+  %4 = fir.address_of(@_QFEvar2) {test.ptr = "var2"} : !fir.ref<f32>
+  %fir_decl_var2 = fir.declare %4 {uniq_name = "var2_fir", test.ptr = "var2_fir"}: (!fir.ref<f32>) -> !fir.ref<f32>
+  %hlfir_decl_var2:2 = hlfir.declare %4 {uniq_name = "var2_hlfir", test.ptr = "var2_hlfir"}: (!fir.ref<f32>) -> (!fir.ref<f32>, !fir.ref<f32>)
+  %5 = fir.address_of(@_QMpointersEp) {test.ptr = "p"} : !fir.ref<!fir.box<!fir.ptr<f32>>>
+  %fir_decl_p = fir.declare %5 {uniq_name = "p_fir", test.ptr = "p_fir"}: (!fir.ref<!fir.box<!fir.ptr<f32>>>) -> !fir.ref<!fir.box<!fir.ptr<f32>>>
+  %hlfir_decl_p:2 = hlfir.declare %5 {uniq_name = "p_hlfir", test.ptr = "p_hlfir"}: (!fir.ref<!fir.box<!fir.ptr<f32>>>) -> (!fir.ref<!fir.box<!fir.ptr<f32>>>, !fir.ref<!fir.box<!fir.ptr<f32>>>)
+  %13 = fir.convert %4 {test.ptr = "box.addr"} : (!fir.ref<f32>) -> !fir.ptr<f32>
+  %fir_decl_convert = fir.declare %13 {uniq_name = "box_addr_fir", test.ptr = "box.addr_fir"}: (!fir.ptr<f32>) -> !fir.ptr<f32>
+  %hlfir_decl_convert:2 = hlfir.declare %13 {uniq_name = "box_addr_hlfir", test.ptr = "box.addr_hlfir"}: (!fir.ptr<f32>) -> (!fir.ptr<f32>, !fir.ptr<f32>)
+  return
+}