[flang-commits] [flang] 4489ef8 - [flang] Fix LBOUND with assumed size array and non constant DIM
Valentin Clement via flang-commits
flang-commits at lists.llvm.org
Fri Jun 24 12:02:17 PDT 2022
Author: Valentin Clement
Date: 2022-06-24T21:02:07+02:00
New Revision: 4489ef8e34fefcbbf4fe44d1307b0cc41a12cfa8
URL: https://github.com/llvm/llvm-project/commit/4489ef8e34fefcbbf4fe44d1307b0cc41a12cfa8
DIFF: https://github.com/llvm/llvm-project/commit/4489ef8e34fefcbbf4fe44d1307b0cc41a12cfa8.diff
LOG: [flang] Fix LBOUND with assumed size array and non constant DIM
LBOUND with a non constant DIM argument use the runtime to allow runtime
verification of DIM <= RANK. The interface uses a descriptor. This caused
undefined behavior because the runtime believed it was seeing an explicit
shape arrays with zero extent and returned `1` (the runtime descriptor
does not allow making a difference between an explicit shape and an
assumed size. Assumed size are not meant to be described by runtime
descriptors).
Fix the issue by setting the last extent of assumed size to `1` when
creating the descriptor to inquire about the LBOUND with the runtime.
This patch is part of the upstreaming effort from fir-dev branch.
Reviewed By: PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D128509
Co-authored-by: Jean Perier <jperier at nvidia.com>
Added:
Modified:
flang/lib/Lower/IntrinsicCall.cpp
flang/test/Lower/Intrinsics/lbound.f90
Removed:
################################################################################
diff --git a/flang/lib/Lower/IntrinsicCall.cpp b/flang/lib/Lower/IntrinsicCall.cpp
index ba22c24ab93f..918d575c1bbc 100644
--- a/flang/lib/Lower/IntrinsicCall.cpp
+++ b/flang/lib/Lower/IntrinsicCall.cpp
@@ -2557,7 +2557,9 @@ void IntrinsicLibrary::genGetEnvironmentVariable(
mlir::Value IntrinsicLibrary::genIand(mlir::Type resultType,
llvm::ArrayRef<mlir::Value> args) {
assert(args.size() == 2);
- return builder.create<mlir::arith::AndIOp>(loc, args[0], args[1]);
+ auto arg0 = builder.createConvert(loc, resultType, args[0]);
+ auto arg1 = builder.createConvert(loc, resultType, args[1]);
+ return builder.create<mlir::arith::AndIOp>(loc, arg0, arg1);
}
// IBCLR
@@ -3456,6 +3458,56 @@ static mlir::Value computeLBOUND(fir::FirOpBuilder &builder, mlir::Location loc,
return builder.create<mlir::arith::SelectOp>(loc, dimIsEmpty, one, lb);
}
+/// Create a fir.box to be passed to the LBOUND runtime.
+/// This ensure that local lower bounds of assumed shape are propagated and that
+/// a fir.box with equivalent LBOUNDs but an explicit shape is created for
+/// assumed size arrays to avoid undefined behaviors in codegen or the runtime.
+static mlir::Value createBoxForLBOUND(mlir::Location loc,
+ fir::FirOpBuilder &builder,
+ const fir::ExtendedValue &array) {
+ if (!array.isAssumedSize())
+ return array.match(
+ [&](const fir::BoxValue &boxValue) -> mlir::Value {
+ // This entity is mapped to a fir.box that may not contain the local
+ // lower bound information if it is a dummy. Rebox it with the local
+ // shape information.
+ mlir::Value localShape = builder.createShape(loc, array);
+ mlir::Value oldBox = boxValue.getAddr();
+ return builder.create<fir::ReboxOp>(loc, oldBox.getType(), oldBox,
+ localShape,
+ /*slice=*/mlir::Value{});
+ },
+ [&](const auto &) -> mlir::Value {
+ // This a pointer/allocatable, or an entity not yet tracked with a
+ // fir.box. For pointer/allocatable, createBox will forward the
+ // descriptor that contains the correct lower bound information. For
+ // other entities, a new fir.box will be made with the local lower
+ // bounds.
+ return builder.createBox(loc, array);
+ });
+ // Assumed sized are not meant to be emboxed. This could cause the undefined
+ // extent cannot safely be understood by the runtime/codegen that will
+ // consider that the dimension is empty and that the related LBOUND value must
+ // be one. Pretend that the related extent is one to get the correct LBOUND
+ // value.
+ llvm::SmallVector<mlir::Value> shape =
+ fir::factory::getExtents(loc, builder, array);
+ assert(!shape.empty() && "assumed size must have at least one dimension");
+ shape.back() = builder.createIntegerConstant(loc, builder.getIndexType(), 1);
+ auto safeToEmbox = array.match(
+ [&](const fir::CharArrayBoxValue &x) -> fir::ExtendedValue {
+ return fir::CharArrayBoxValue{x.getAddr(), x.getLen(), shape,
+ x.getLBounds()};
+ },
+ [&](const fir::ArrayBoxValue &x) -> fir::ExtendedValue {
+ return fir::ArrayBoxValue{x.getAddr(), shape, x.getLBounds()};
+ },
+ [&](const auto &) -> fir::ExtendedValue {
+ fir::emitFatalError(loc, "not an assumed size array");
+ });
+ return builder.createBox(loc, safeToEmbox);
+}
+
// LBOUND
fir::ExtendedValue
IntrinsicLibrary::genLbound(mlir::Type resultType,
@@ -3506,25 +3558,7 @@ IntrinsicLibrary::genLbound(mlir::Type resultType,
return builder.createConvert(loc, resultType, lb);
}
- mlir::Value box = array.match(
- [&](const fir::BoxValue &boxValue) -> mlir::Value {
- // This entity is mapped to a fir.box that may not contain the local
- // lower bound information if it is a dummy. Rebox it with the local
- // shape information.
- mlir::Value localShape = builder.createShape(loc, array);
- mlir::Value oldBox = boxValue.getAddr();
- return builder.create<fir::ReboxOp>(
- loc, oldBox.getType(), oldBox, localShape, /*slice=*/mlir::Value{});
- },
- [&](const auto &) -> mlir::Value {
- // This a pointer/allocatable, or an entity not yet tracked with a
- // fir.box. For pointer/allocatable, createBox will forward the
- // descriptor that contains the correct lower bound information. For
- // other entities, a new fir.box will be made with the local lower
- // bounds.
- return builder.createBox(loc, array);
- });
-
+ fir::ExtendedValue box = createBoxForLBOUND(loc, builder, array);
return builder.createConvert(
loc, resultType,
fir::runtime::genLboundDim(builder, loc, fir::getBase(box), dim));
diff --git a/flang/test/Lower/Intrinsics/lbound.f90 b/flang/test/Lower/Intrinsics/lbound.f90
index 2a84d760c89f..3ea08800b0fc 100644
--- a/flang/test/Lower/Intrinsics/lbound.f90
+++ b/flang/test/Lower/Intrinsics/lbound.f90
@@ -37,11 +37,11 @@ subroutine lbound_test_2(a, dim, res)
res = lbound(a, dim, 8)
end subroutine
-! CHECK: %[[VAL_0:.*]] = fir.undefined index
subroutine lbound_test_3(a, dim, res)
real, dimension(2:10, 3:*) :: a
integer(8):: dim, res
! CHECK: %[[VAL_1:.*]] = fir.load %arg1 : !fir.ref<i64>
+! CHECK: %[[VAL_0:.*]] = arith.constant 1 : index
! CHECK: %[[VAL_2:.*]] = fir.shape_shift %{{.*}}, %{{.*}}, %{{.*}}, %[[VAL_0]] : (index, index, index, index) -> !fir.shapeshift<2>
! CHECK: %[[VAL_3:.*]] = fir.embox %arg0(%[[VAL_2]]) : (!fir.ref<!fir.array<9x?xf32>>, !fir.shapeshift<2>) -> !fir.box<!fir.array<9x?xf32>>
! CHECK: %[[VAL_4:.*]] = fir.address_of(
More information about the flang-commits
mailing list