[flang-commits] [flang] bacbf26 - [flang] allow assumed-rank box in fir.alloca (#95947)

[via flang-commits]

Author: jeanPerier
Date: 2024-06-19T09:56:36+02:00
New Revision: bacbf26b4cb64dbf77819ff5a2b0f4c26d111c66

URL: https://github.com/llvm/llvm-project/commit/bacbf26b4cb64dbf77819ff5a2b0f4c26d111c66
DIFF: https://github.com/llvm/llvm-project/commit/bacbf26b4cb64dbf77819ff5a2b0f4c26d111c66.diff

LOG: [flang] allow assumed-rank box in fir.alloca (#95947)

The alloca can be maximized with the maximum number or ranks, which is
reasonable (15 currently as per the standard). Introducing a rank based
dynamic allocation would complexify alloca hoisting and stack size
analysis (this can be revisited if the standard changes to allow more
ranks).

No change is needed since this is already reflected in how the fir.box
type is translated to LLVM.

Added: 
    

Modified: 
    flang/lib/Optimizer/Dialect/FIROps.cpp
    flang/test/Fir/convert-to-llvm.fir

Removed: 
    


################################################################################
diff  --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
index ea8a9752eeeee..6cf0dd23fe456 100644
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -272,8 +272,6 @@ mlir::LogicalResult fir::AllocaOp::verify() {
   mlir::Type outType = getType();
   if (!mlir::isa<fir::ReferenceType>(outType))
     return emitOpError("must be a !fir.ref type");
-  if (fir::isa_unknown_size_box(fir::dyn_cast_ptrEleTy(outType)))
-    return emitOpError("cannot allocate !fir.box of unknown rank or type");
   return mlir::success();
 }
 

diff  --git a/flang/test/Fir/convert-to-llvm.fir b/flang/test/Fir/convert-to-llvm.fir
index d7059671d3a88..857d5b2ff303c 100644
--- a/flang/test/Fir/convert-to-llvm.fir
+++ b/flang/test/Fir/convert-to-llvm.fir
@@ -1277,6 +1277,20 @@ func.func @alloca_array_with_holes(%0 : index, %1 : index) -> !fir.ref<!fir.arra
 
 // -----
 
+// Test alloca of assumed-rank box
+
+func.func @alloca_assumed_rank_box() -> !fir.ref<!fir.box<!fir.array<*:f32>>> {
+  %a = fir.alloca !fir.box<!fir.array<*:f32>>
+  return %a : !fir.ref<!fir.box<!fir.array<*:f32>>>
+}
+// CHECK-LABEL: llvm.func @alloca_assumed_rank_box
+// CHECK: %[[ONE:.*]] = llvm.mlir.constant(1 : i64) : i64
+// GENERIC: llvm.alloca %[[ONE]] x !llvm.struct<(ptr, i64, i32, i8, i8, i8, i8, array<15 x array<3 x i64>>)> : (i64) -> !llvm.ptr
+// AMDGPU: %[[AA:.*]] = llvm.alloca %[[ONE]] x !llvm.struct<(ptr, i64, i32, i8, i8, i8, i8, array<15 x array<3 x i64>>)> : (i64) -> !llvm.ptr<5>
+// AMDGPU: llvm.addrspacecast %[[AA]] : !llvm.ptr<5> to !llvm.ptr
+
+// -----
+
 // Test `fir.select_case` operation conversion with INTEGER.
 
 func.func @select_case_integer(%arg0: !fir.ref<i32>) -> i32 {