[flang][NFC] use hlfir.declare first result when both results are raw pointers (llvm#132261)

Currently, the helpers to get fir::ExtendedValue out of hlfir::Entity
use hlfir.declare second result (`#1`) in most cases. This is because
this result is the same as the input and matches what FIR was getting
before lowering to HLFIR.

But this creates odd situations when both hlfir.declare are raw pointers
and either result ends-up being used in the IR depending on whether the
code was generated by a helper using fir::ExtendedValue, or via "pure
HLFIR" helpers using the first result.

This will typically prevent simple CSE and easy identification that two
operation (e.g load/store) are touching the exact same memory location
without using alias analysis or "manual detection" (looking for common
hlfir.declare defining op).

Hence, when hlfir.declare results are both raw pointers, use `#0` when
producing `fir::ExtendedValue`.
When `#0` is a fir.box, keep using `#1` because these are not the same. 
The only code change is in HLFIRTools.cpp and is pretty small, but there
is a big test fallout of `#1` to `#0`.

Author: jeanPerier

flang/lib/Optimizer/Builder/HLFIRTools.cpp

@@ -186,14 +186,24 @@ static fir::CharBoxValue genUnboxChar(mlir::Location loc,
   return {addr, len};
 }
 
+// To maximize chances of identifying usage of a same variables in the IR,
+// always return the hlfirBase result of declare/associate if it is a raw
+// pointer.
+static mlir::Value getFirBaseHelper(mlir::Value hlfirBase,
+                                    mlir::Value firBase) {
+  if (fir::isa_ref_type(hlfirBase.getType()))
+    return hlfirBase;
+  return firBase;
+}
+
 mlir::Value hlfir::Entity::getFirBase() const {
   if (fir::FortranVariableOpInterface variable = getIfVariableInterface()) {
     if (auto declareOp =
             mlir::dyn_cast<hlfir::DeclareOp>(variable.getOperation()))
-      return declareOp.getOriginalBase();
+      return getFirBaseHelper(declareOp.getBase(), declareOp.getOriginalBase());
     if (auto associateOp =
             mlir::dyn_cast<hlfir::AssociateOp>(variable.getOperation()))
-      return associateOp.getFirBase();
+      return getFirBaseHelper(associateOp.getBase(), associateOp.getFirBase());
   }
   return getBase();
 }

flang/test/HLFIR/all-lowering.fir

@@ -90,7 +90,7 @@ func.func @_QPall3(%arg0: !fir.ref<!fir.array<2x!fir.logical<4>>> {fir.bindc_nam
 
 // CHECK-DAG:     %[[MASK_ADDR:.*]] = fir.address_of
 // CHECK-DAG:     %[[MASK_VAR:.*]]:2 = hlfir.declare %[[MASK_ADDR]](%[[MASK_SHAPE:.*]])
-// CHECK-DAG:     %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#1(%[[MASK_SHAPE:.*]])
+// CHECK-DAG:     %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#0(%[[MASK_SHAPE:.*]])
 
 // CHECK-DAG:     %[[DIM:.*]] = arith.constant 1 : i32
 

flang/test/HLFIR/any-lowering.fir

@@ -93,7 +93,7 @@ func.func @_QPany3(%arg0: !fir.ref<!fir.array<2x!fir.logical<4>>> {fir.bindc_nam
 
 // CHECK-DAG:     %[[MASK_ADDR:.*]] = fir.address_of
 // CHECK-DAG:     %[[MASK_VAR:.*]]:2 = hlfir.declare %[[MASK_ADDR]](%[[MASK_SHAPE:.*]])
-// CHECK-DAG:     %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#1(%[[MASK_SHAPE:.*]])
+// CHECK-DAG:     %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#0(%[[MASK_SHAPE:.*]])
 
 // CHECK-DAG:     %[[DIM:.*]] = arith.constant 1 : i32
 

flang/test/HLFIR/associate-codegen.fir

@@ -88,7 +88,7 @@ func.func @associate_char(%arg0: !fir.boxchar<1> ) {
 // CHECK:           %[[VAL_16:.*]] = arith.subi %[[VAL_7]], %[[VAL_15]] : index
 // CHECK:           fir.do_loop %[[VAL_17:.*]] = %[[VAL_2]]#1 to %[[VAL_16]] step %[[VAL_15]] {
 // CHECK:             %[[VAL_18:.*]] = arith.subi %[[VAL_17]], %[[VAL_2]]#1 : index
-// CHECK:             %[[VAL_19:.*]] = fir.convert %[[VAL_6]]#1 : (!fir.ref<!fir.char<1>>) -> !fir.ref<!fir.array<1x!fir.char<1>>>
+// CHECK:             %[[VAL_19:.*]] = fir.convert %[[VAL_6]]#0 : (!fir.ref<!fir.char<1>>) -> !fir.ref<!fir.array<1x!fir.char<1>>>
 // CHECK:             %[[VAL_20:.*]] = fir.coordinate_of %[[VAL_19]], %[[VAL_18]] : (!fir.ref<!fir.array<1x!fir.char<1>>>, index) -> !fir.ref<!fir.char<1>>
 // CHECK:             %[[VAL_21:.*]] = fir.load %[[VAL_20]] : !fir.ref<!fir.char<1>>
 // CHECK:             %[[VAL_22:.*]] = fir.convert %[[VAL_8]] : (!fir.ref<!fir.char<1,?>>) -> !fir.ref<!fir.array<?x!fir.char<1>>>
@@ -233,7 +233,7 @@ func.func @test_shape_of(%arg0: !fir.ref<!fir.array<4x3xi32>>) {
 // CHECK:           %[[VAL_14:.*]] = fir.insert_value %[[VAL_13]], %[[VAL_6]], [1 : index] : (tuple<!fir.heap<!fir.array<3x4xi32>>, i1>, i1) -> tuple<!fir.heap<!fir.array<3x4xi32>>, i1>
 // CHECK:           %[[VAL_15:.*]] = fir.insert_value %[[VAL_14]], %[[VAL_5]]#0, [0 : index] : (tuple<!fir.heap<!fir.array<3x4xi32>>, i1>, !fir.heap<!fir.array<3x4xi32>>) -> tuple<!fir.heap<!fir.array<3x4xi32>>, i1>
 // CHECK:           %[[VAL_16:.*]] = fir.convert %[[VAL_5]]#0 : (!fir.heap<!fir.array<3x4xi32>>) -> !fir.ref<!fir.array<3x4xi32>>
-// CHECK:           %[[VAL_17:.*]] = fir.convert %[[VAL_5]]#1 : (!fir.heap<!fir.array<3x4xi32>>) -> !fir.ref<!fir.array<3x4xi32>>
+// CHECK:           %[[VAL_17:.*]] = fir.convert %[[VAL_5]]#0 : (!fir.heap<!fir.array<3x4xi32>>) -> !fir.ref<!fir.array<3x4xi32>>
 // CHECK:           %[[VAL_18:.*]] = fir.convert %[[VAL_17]] : (!fir.ref<!fir.array<3x4xi32>>) -> !fir.heap<!fir.array<3x4xi32>>
 // CHECK:           fir.freemem %[[VAL_18]] : !fir.heap<!fir.array<3x4xi32>>
 // CHECK:           return
@@ -266,7 +266,7 @@ func.func @test_multiple_associations(%arg0: !hlfir.expr<1x2xi32>) {
 // CHECK:           %[[VAL_11:.*]] = fir.insert_value %[[VAL_10]], %[[VAL_8]], [1 : index] : (tuple<!fir.heap<!fir.array<1x2xi32>>, i1>, i1) -> tuple<!fir.heap<!fir.array<1x2xi32>>, i1>
 // CHECK:           %[[VAL_12:.*]] = fir.insert_value %[[VAL_11]], %[[VAL_9]]#0, [0 : index] : (tuple<!fir.heap<!fir.array<1x2xi32>>, i1>, !fir.heap<!fir.array<1x2xi32>>) -> tuple<!fir.heap<!fir.array<1x2xi32>>, i1>
 // CHECK:           %[[VAL_13:.*]] = fir.convert %[[VAL_9]]#0 : (!fir.heap<!fir.array<1x2xi32>>) -> !fir.ref<!fir.array<1x2xi32>>
-// CHECK:           %[[VAL_14:.*]] = fir.convert %[[VAL_9]]#1 : (!fir.heap<!fir.array<1x2xi32>>) -> !fir.ref<!fir.array<1x2xi32>>
+// CHECK:           %[[VAL_14:.*]] = fir.convert %[[VAL_9]]#0 : (!fir.heap<!fir.array<1x2xi32>>) -> !fir.ref<!fir.array<1x2xi32>>
 // associate 1:
 // CHECK:           %[[VAL_15:.*]] = hlfir.shape_of %[[VAL_0]] : (!hlfir.expr<1x2xi32>) -> !fir.shape<2>
 // CHECK:           %[[VAL_16:.*]] = arith.constant 1 : index
@@ -279,7 +279,7 @@ func.func @test_multiple_associations(%arg0: !hlfir.expr<1x2xi32>) {
 // CHECK:           %[[VAL_22:.*]] = fir.insert_value %[[VAL_21]], %[[VAL_19]], [1 : index] : (tuple<!fir.heap<!fir.array<1x2xi32>>, i1>, i1) -> tuple<!fir.heap<!fir.array<1x2xi32>>, i1>
 // CHECK:           %[[VAL_23:.*]] = fir.insert_value %[[VAL_22]], %[[VAL_20]]#0, [0 : index] : (tuple<!fir.heap<!fir.array<1x2xi32>>, i1>, !fir.heap<!fir.array<1x2xi32>>) -> tuple<!fir.heap<!fir.array<1x2xi32>>, i1>
 // CHECK:           %[[VAL_24:.*]] = fir.convert %[[VAL_20]]#0 : (!fir.heap<!fir.array<1x2xi32>>) -> !fir.ref<!fir.array<1x2xi32>>
-// CHECK:           %[[VAL_25:.*]] = fir.convert %[[VAL_20]]#1 : (!fir.heap<!fir.array<1x2xi32>>) -> !fir.ref<!fir.array<1x2xi32>>
+// CHECK:           %[[VAL_25:.*]] = fir.convert %[[VAL_20]]#0 : (!fir.heap<!fir.array<1x2xi32>>) -> !fir.ref<!fir.array<1x2xi32>>
 // end associate 0:
 // CHECK:           %[[VAL_26:.*]] = fir.convert %[[VAL_14]] : (!fir.ref<!fir.array<1x2xi32>>) -> !fir.heap<!fir.array<1x2xi32>>
 // CHECK:           fir.freemem %[[VAL_26]] : !fir.heap<!fir.array<1x2xi32>>
@@ -414,7 +414,7 @@ func.func @_QPtest_multitple_associates_for_same_expr() {
 // CHECK:           %[[VAL_17:.*]] = fir.insert_value %[[VAL_16]], %[[VAL_14]], [1 : index] : (tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>, i1) -> tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>
 // CHECK:           %[[VAL_18:.*]] = fir.insert_value %[[VAL_17]], %[[VAL_15]]#0, [0 : index] : (tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>, !fir.heap<!fir.array<10x!fir.char<1>>>) -> tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>
 // CHECK:           %[[VAL_19:.*]] = fir.convert %[[VAL_15]]#0 : (!fir.heap<!fir.array<10x!fir.char<1>>>) -> !fir.ref<!fir.array<10x!fir.char<1>>>
-// CHECK:           %[[VAL_20:.*]] = fir.convert %[[VAL_15]]#1 : (!fir.heap<!fir.array<10x!fir.char<1>>>) -> !fir.ref<!fir.array<10x!fir.char<1>>>
+// CHECK:           %[[VAL_20:.*]] = fir.convert %[[VAL_15]]#0 : (!fir.heap<!fir.array<10x!fir.char<1>>>) -> !fir.ref<!fir.array<10x!fir.char<1>>>
 // CHECK:           %[[VAL_21:.*]] = fir.convert %[[VAL_20]] : (!fir.ref<!fir.array<10x!fir.char<1>>>) -> !fir.heap<!fir.array<10x!fir.char<1>>>
 // CHECK:           fir.freemem %[[VAL_21]] : !fir.heap<!fir.array<10x!fir.char<1>>>
 // CHECK:           %[[VAL_22:.*]] = fir.allocmem !fir.array<10x!fir.char<1>> {bindc_name = ".tmp", uniq_name = ""}
@@ -425,7 +425,7 @@ func.func @_QPtest_multitple_associates_for_same_expr() {
 // CHECK:           %[[VAL_26:.*]] = fir.insert_value %[[VAL_25]], %[[VAL_23]], [1 : index] : (tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>, i1) -> tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>
 // CHECK:           %[[VAL_27:.*]] = fir.insert_value %[[VAL_26]], %[[VAL_24]]#0, [0 : index] : (tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>, !fir.heap<!fir.array<10x!fir.char<1>>>) -> tuple<!fir.heap<!fir.array<10x!fir.char<1>>>, i1>
 // CHECK:           %[[VAL_28:.*]] = fir.convert %[[VAL_24]]#0 : (!fir.heap<!fir.array<10x!fir.char<1>>>) -> !fir.ref<!fir.array<10x!fir.char<1>>>
-// CHECK:           %[[VAL_29:.*]] = fir.convert %[[VAL_24]]#1 : (!fir.heap<!fir.array<10x!fir.char<1>>>) -> !fir.ref<!fir.array<10x!fir.char<1>>>
+// CHECK:           %[[VAL_29:.*]] = fir.convert %[[VAL_24]]#0 : (!fir.heap<!fir.array<10x!fir.char<1>>>) -> !fir.ref<!fir.array<10x!fir.char<1>>>
 // CHECK:           %[[VAL_30:.*]] = fir.convert %[[VAL_29]] : (!fir.ref<!fir.array<10x!fir.char<1>>>) -> !fir.heap<!fir.array<10x!fir.char<1>>>
 // CHECK:           fir.freemem %[[VAL_30]] : !fir.heap<!fir.array<10x!fir.char<1>>>
 // CHECK:           fir.freemem %[[VAL_4]]#0 : !fir.heap<!fir.array<10x!fir.char<1>>>

flang/test/HLFIR/assumed-type-actual-args.f90

@@ -106,7 +106,7 @@ subroutine s5b(x)
 ! CHECK-SAME:                        %[[VAL_0:.*]]: !fir.ref<none> {fir.bindc_name = "x"}) {
 ! CHECK:           %[[DSCOPE:.*]] = fir.dummy_scope : !fir.dscope
 ! CHECK:           %[[VAL_1:.*]]:2 = hlfir.declare %[[VAL_0]] dummy_scope %[[DSCOPE]] {uniq_name = "_QFtest1Ex"} : (!fir.ref<none>, !fir.dscope) -> (!fir.ref<none>, !fir.ref<none>)
-! CHECK:           fir.call @_QPs1(%[[VAL_1]]#1) fastmath<contract> : (!fir.ref<none>) -> ()
+! CHECK:           fir.call @_QPs1(%[[VAL_1]]#0) fastmath<contract> : (!fir.ref<none>) -> ()
 ! CHECK:           return
 ! CHECK:         }
 

flang/test/HLFIR/boxchar_emboxing.f90

@@ -18,7 +18,7 @@
 ! CHECK:           %[[VAL_9:.*]] = fir.address_of(@_QQclX4641494C) : !fir.ref<!fir.char<1,4>>
 ! CHECK:           %[[VAL_10:.*]] = arith.constant 4 : index
 ! CHECK:           %[[VAL_11:.*]]:2 = hlfir.declare %[[VAL_9]] typeparams %[[VAL_10]] {fortran_attrs = #fir.var_attrs<parameter>, uniq_name = "_QQclX4641494C"} : (!fir.ref<!fir.char<1,4>>, index) -> (!fir.ref<!fir.char<1,4>>, !fir.ref<!fir.char<1,4>>)
-! CHECK:           %[[VAL_12:.*]] = fir.convert %[[VAL_11]]#1 : (!fir.ref<!fir.char<1,4>>) -> !fir.ref<i8>
+! CHECK:           %[[VAL_12:.*]] = fir.convert %[[VAL_11]]#0 : (!fir.ref<!fir.char<1,4>>) -> !fir.ref<i8>
 ! CHECK:           %[[VAL_13:.*]] = fir.convert %[[VAL_10]] : (index) -> i64
 ! CHECK:           %[[VAL_14:.*]] = arith.constant false
 ! CHECK:           %[[VAL_15:.*]] = arith.constant false
@@ -62,7 +62,7 @@ end subroutine test1
 ! CHECK:           %[[VAL_11:.*]] = fir.address_of(@_QQclX4641494C) : !fir.ref<!fir.char<1,4>>
 ! CHECK:           %[[VAL_12:.*]] = arith.constant 4 : index
 ! CHECK:           %[[VAL_13:.*]]:2 = hlfir.declare %[[VAL_11]] typeparams %[[VAL_12]] {fortran_attrs = #fir.var_attrs<parameter>, uniq_name = "_QQclX4641494C"} : (!fir.ref<!fir.char<1,4>>, index) -> (!fir.ref<!fir.char<1,4>>, !fir.ref<!fir.char<1,4>>)
-! CHECK:           %[[VAL_14:.*]] = fir.convert %[[VAL_13]]#1 : (!fir.ref<!fir.char<1,4>>) -> !fir.ref<i8>
+! CHECK:           %[[VAL_14:.*]] = fir.convert %[[VAL_13]]#0 : (!fir.ref<!fir.char<1,4>>) -> !fir.ref<i8>
 ! CHECK:           %[[VAL_15:.*]] = fir.convert %[[VAL_12]] : (index) -> i64
 ! CHECK:           %[[VAL_16:.*]] = arith.constant false
 ! CHECK:           %[[VAL_17:.*]] = arith.constant false

flang/test/HLFIR/count-lowering.fir

@@ -92,7 +92,7 @@ func.func @_QPcount3(%arg0: !fir.ref<!fir.array<2xi32>> {fir.bindc_name = "s"})
 
 // CHECK-DAG:     %[[MASK_ADDR:.*]] = fir.address_of
 // CHECK-DAG:     %[[MASK_VAR:.*]]:2 = hlfir.declare %[[MASK_ADDR]](%[[MASK_SHAPE:.*]])
-// CHECK-DAG:     %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#1(%[[MASK_SHAPE:.*]])
+// CHECK-DAG:     %[[MASK_BOX:.*]] = fir.embox %[[MASK_VAR]]#0(%[[MASK_SHAPE:.*]])
 
 // CHECK-DAG:     %[[DIM:.*]] = arith.constant 1 : i32
 

flang/test/HLFIR/cshift-lowering.fir

@@ -21,7 +21,7 @@ func.func @cshift1(%arg0: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "a"}, %a
 // CHECK:           %[[VAL_9:.*]] = fir.shape %[[VAL_4]] : (index) -> !fir.shape<1>
 // CHECK:           %[[VAL_10:.*]] = fir.embox %[[VAL_8]](%[[VAL_9]]) : (!fir.heap<!fir.array<?xi32>>, !fir.shape<1>) -> !fir.box<!fir.heap<!fir.array<?xi32>>>
 // CHECK:           fir.store %[[VAL_10]] to %[[VAL_5]] : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
-// CHECK:           %[[VAL_11:.*]] = fir.load %[[VAL_7]]#1 : !fir.ref<i32>
+// CHECK:           %[[VAL_11:.*]] = fir.load %[[VAL_7]]#0 : !fir.ref<i32>
 // CHECK:           %[[VAL_13:.*]] = fir.convert %[[VAL_5]] : (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>) -> !fir.ref<!fir.box<none>>
 // CHECK:           %[[VAL_14:.*]] = fir.convert %[[VAL_6]]#1 : (!fir.box<!fir.array<?xi32>>) -> !fir.box<none>
 // CHECK:           %[[VAL_15:.*]] = fir.convert %[[VAL_11]] : (i32) -> i64

flang/test/HLFIR/dot_product-lowering.fir

@@ -70,8 +70,8 @@ func.func @_QPdot_product2(%arg0: !fir.box<!fir.array<?x!fir.logical<4>>> {fir.b
 // CHECK-DAG:     %[[RHS_VAR:.*]]:2 = hlfir.declare %[[ARG1]]
 // CHECK-DAG:     %[[RES_VAR:.*]]:2 = hlfir.declare %[[ARG2]]
 
-// CHECK-DAG:     %[[LHS_BOX:.*]] = fir.embox %[[LHS_VAR]]#1
-// CHECK-DAG:     %[[RHS_BOX:.*]] = fir.embox %[[RHS_VAR]]#1
+// CHECK-DAG:     %[[LHS_BOX:.*]] = fir.embox %[[LHS_VAR]]#0
+// CHECK-DAG:     %[[RHS_BOX:.*]] = fir.embox %[[RHS_VAR]]#0
 // CHECK-DAG:     %[[LHS_ARG:.*]] = fir.convert %[[LHS_BOX]] : (!fir.box<!fir.array<5xi32>>) -> !fir.box<none>
 // CHECK-DAG:     %[[RHS_ARG:.*]] = fir.convert %[[RHS_BOX]] : (!fir.box<!fir.array<5xi32>>) -> !fir.box<none>
 

flang/test/HLFIR/elemental-codegen-nested.fir

@@ -34,7 +34,7 @@
 // CHECK:             %[[VAL_27:.*]] = fir.insert_value %[[VAL_26]], %[[VAL_21]], [1 : index] : (tuple<!fir.heap<!fir.array<2xf32>>, i1>, i1) -> tuple<!fir.heap<!fir.array<2xf32>>, i1>
 // CHECK:             %[[VAL_28:.*]] = fir.insert_value %[[VAL_27]], %[[VAL_20]]#0, [0 : index] : (tuple<!fir.heap<!fir.array<2xf32>>, i1>, !fir.heap<!fir.array<2xf32>>) -> tuple<!fir.heap<!fir.array<2xf32>>, i1>
 // CHECK:             %[[VAL_29:.*]] = fir.convert %[[VAL_20]]#0 : (!fir.heap<!fir.array<2xf32>>) -> !fir.ref<!fir.array<2xf32>>
-// CHECK:             %[[VAL_30:.*]] = fir.convert %[[VAL_20]]#1 : (!fir.heap<!fir.array<2xf32>>) -> !fir.ref<!fir.array<2xf32>>
+// CHECK:             %[[VAL_30:.*]] = fir.convert %[[VAL_20]]#0 : (!fir.heap<!fir.array<2xf32>>) -> !fir.ref<!fir.array<2xf32>>
 // CHECK:             %[[VAL_31:.*]] = fir.embox %[[VAL_29]](%[[VAL_18]]) : (!fir.ref<!fir.array<2xf32>>, !fir.shape<1>) -> !fir.box<!fir.array<2xf32>>
 // CHECK:             %[[VAL_32:.*]] = fir.convert %[[VAL_31]] : (!fir.box<!fir.array<2xf32>>) -> !fir.box<!fir.array<?xf32>>
 // CHECK:             %[[VAL_33:.*]] = fir.call @_QPfoo(%[[VAL_32]]) fastmath<contract> : (!fir.box<!fir.array<?xf32>>) -> f32