8 Commits

Author SHA1 Message Date
Tom Eccles
4cc9437a7e [flang] Set default to -ffpcontract=fast
Following RFC at
https://discourse.llvm.org/t/rfc-ffp-contract-default-value/66301

This adds the `fastmath<contract>` attribute to `fir.call` and some
floating point arithmetic operations (hence the many test changes).
Instead of testing for this specific attribute, I am using a regular
expression to match any attributes.
2022-11-17 15:49:51 +00:00
Slava Zakharin
73026a4fbf [flang] Changed lowering for allocatable assignment to make array-value-copy correct.
Array-value-copy fails to generate a temporary array for case like this:
subroutine bug(b)
  real, allocatable :: b(:)
  b = b(2:1:-1)
end subroutine

Since LHS may need to be reallocated, lowering produces the following FIR:
%rhs_load = fir.array_load %b %slice

%lhs_mem = fir.if %b_is_allocated_with_right_shape {
   fir.result %b
} else {
   %new_storage = fir.allocmem %rhs_shape
   fir.result %new_storage
}

%lhs = fir.array_load %lhs_mem
%loop = fir.do_loop {
 ....
}
fir.array_merge_store %lhs, %loop to %lhs_mem
// deallocate old storage if reallocation occured,
// and update b descriptor if needed.

Since %b in array_load and %lhs_mem in array_merge_store are not the same SSA
values, array-value-copy does not detect the conflict and does not produce
a temporary array. This causes incorrect result in runtime.

The suggested change in lowering is to generate this:
%rhs_load = fir.array_load %b %slice
%lhs_mem = fir.if %b_is_allocated_with_right_shape {
   %lhs = fir.array_load %b
   %loop = fir.do_loop {
      ....
   }
   fir.array_merge_store %lhs, %loop to %b
   fir.result %b
} else {
   %new_storage = fir.allocmem %rhs_shape
   %lhs = fir.array_load %new_storage
   %loop = fir.do_loop {
      ....
   }
   fir.array_merge_store %lhs, %loop to %new_storage
   fir.result %new_storage
}
// deallocate old storage if reallocation occured,
// and update b descriptor if needed.

Note that there are actually 3 branches in FIR, so the assignment loops
are currently produced in three copies, which is a code-size issue.
It is possible to generate just two branches with two copies of the loops,
but it is not addressed in this change-set.

Differential Revision: https://reviews.llvm.org/D129314
2022-07-08 09:41:34 -07:00
Eric Schweitz
68cfb6a8e5
Fixes assertion that arose from bad FIR being constructed.
* Fix assertion strings.

* Fixes assertion that arose from bad FIR being constructed.

With the default member-wise component assignment, the LHS and RHS may
be compatible but distinct types. This change to lowering manages both
the LHS and RHS independently rather than assume the two types are
identical. This avoids creating bogus FIR and asserting/crashing in
codegen.

Update the tests with the member-wise copy code.

This patch is part of the upstreaming effort from fir-dev branch.

Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D127297
2022-06-10 08:11:43 +02:00
Nikita Popov
f09b0c8422 [flang] Update memcpy intrinsic mangling for opaque pointers
Flang is manually mangling names for memset/memcpy/memmove
intrinsics, so we need to update the mangling to use the opaque
pointer format (p0 instead of p0i8).
2022-06-02 12:11:13 +02:00
Valentin Clement
fe252f8ed6
[flang] Lower boxed procedure
In FIR, we want to wrap function pointers in a special box known as a
boxproc value. Fortran has a limited form of dynamic scoping
[https://tinyurl.com/2p8v2hw7] between "host procedures" and "internal
procedures". There are a number of implementations possible.

Boxproc typed values abstract away the implementation details of when a
function pointer can be passed directly (as a raw address) and when a
function pointer has to account for the presence of a dynamic scope.
When lowering Fortran syntax to FIR, all function pointers are emboxed
as boxproc values.

When creating LLVM IR, we must strip away the abstraction and produce
low-level LLVM "assembly" code. This patch implements that
transformation as converting the boxproc values to either raw function
pointers or executable trampolines on the stack as needed. The
trampoline then captures the dynamic scope context within an executable
thunk that can be passed instead of the function's raw address.

Some extra handling is required for Fortran functions that return a
character value to deal with LEN values here.

Some of the code in Bridge.cpp and ConvertExpr.cpp and be re-arranged to
faciliate the upstreaming effort.

This patch is part of the upstreaming effort from fir-dev branch.

Reviewed By: jeanPerier, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D122223

Co-authored-by: mleair <leairmark@gmail.com>
Co-authored-by: Jean Perier <jperier@nvidia.com>
Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Co-authored-by: V Donaldson <vdonaldson@nvidia.com>
Co-authored-by: Kiran Chandramohan <kiran.chandramohan@arm.com>
2022-03-22 15:41:11 +01:00
Valentin Clement
859d4a18b5
[flang] Lower more cases of assignments on allocatable variables
This patch enables the lowering of various allocatable assignements
for character type and numeric types.

This patch is part of the upstreaming effort from fir-dev branch.

Depends on D120819

Reviewed By: PeteSteinfeld, schweitz

Differential Revision: https://reviews.llvm.org/D120820

Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Co-authored-by: Jean Perier <jperier@nvidia.com>
2022-03-02 20:05:23 +01:00
Valentin Clement
17d71347b2
[flang] Handle module in lowering pass
This patch enables the lowering of basic modules and functions/subroutines
in modules.

This patch is part of the upstreaming effort from fir-dev branch.

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D120819

Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Co-authored-by: Jean Perier <jperier@nvidia.com>
2022-03-02 18:26:43 +01:00
Valentin Clement
2a59ead118
[flang] Lower allocatable assignment for scalar
Add lowering for simple assignement on allocatable
scalars.

This patch is part of the upstreaming effort from fir-dev branch.

Depends on D120483

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D120488

Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Co-authored-by: Jean Perier <jperier@nvidia.com>
2022-02-24 18:13:18 +01:00