[flang][OpenMP] Ignore DECLARE_SIMD and warn about missing implementa… (#232712)

…tion Currently DECLARE_SIMD emits a "not yet implemented" error in the MLIR to LLVM IR translation. DECLARE_SIMD is a hint to the compiler and ignoring it is technically speaking a conforming implementation (although obviously not desirable). Do not abort compilation when DECLARE_SIMD is encountered, but emit a warning that it's currently ignored. (cherry picked from commit 5ca62fdee645ec253263e41a45fe626c6b66be22) Fixes: https://github.com/llvm/llvm-project/issues/234108
2026-10-23 06:48:25 +00:00
1 parent fde947fd58
commit 2cc5b8ca55
@@ -1928,6 +1928,11 @@ void OmpStructureChecker::Leave(const parser::OmpThreadprivateDirective &x) {
 void OmpStructureChecker::Enter(const parser::OmpDeclareSimdDirective &x) {
  const parser::OmpDirectiveName &dirName{x.v.DirName()};

+  unsigned version{context_.langOptions().OpenMPVersion};
+  context_.Say(dirName.source,
+      "%s directive is not implemented yet and will be ignored"_warn_en_US,
+      GetUpperName(dirName.v, version));
+
  const Scope &containingScope = context_.FindScope(dirName.source);
  const Scope &progUnitScope = GetProgramUnitContaining(containingScope);

@@ -4,6 +4,7 @@ subroutine test_cray_pointer_usage
  integer :: i
  real(8) :: var(*), pointee(2)
  pointer(ivar, var)
+  ! WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  ! ERROR: Cray Pointee 'var' may not appear in LINEAR clause
  ! ERROR: List item 'var' in LINEAR clause must be a scalar variable
  ! ERROR: The list item 'var' specified without the REF 'linear-modifier' must be of INTEGER type
@@ -21,6 +21,7 @@ end subroutine requires_2

 subroutine declare_simd_1(a, b)
  real(8), intent(inout) :: a, b
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !ERROR: 'a' in ALIGNED clause must be of type C_PTR, POINTER or ALLOCATABLE
  !$omp declare simd(declare_simd_1) aligned(a)
  a = 3.14 + b
@@ -38,6 +39,7 @@ end module m1
 subroutine declare_simd_2
  use m1
  procedure (sub) sub1
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !ERROR: INBRANCH and NOTINBRANCH clauses are mutually exclusive and may not appear on the same DECLARE SIMD directive
  !$omp declare simd(sub1) inbranch notinbranch
  procedure (sub), pointer::p
@@ -1,6 +1,7 @@
-! RUN: %python %S/../test_errors.py %s %flang -fopenmp
+! RUN: %python %S/../test_errors.py %s %flang -fopenmp -Werror -Wno-experimental-option
 ! Test the source code starting with omp syntax

+!WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
 !$omp declare simd
 integer :: x
 end
@@ -6,12 +6,14 @@

 interface
  subroutine add2(i)
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !WARNING: 'DECLARE SIMD' directive in an interface body has no effect [-Wopenmp-usage]
  !$omp declare simd(add2) linear(i:1)
    integer :: i
  end subroutine

  subroutine add3(i)
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !WARNING: 'DECLARE SIMD' directive in an interface body has no effect [-Wopenmp-usage]
  !$omp declare simd
    integer :: i
@@ -20,8 +22,10 @@ end interface

 contains

-! A DECLARE SIMD in an actual definition is fine and must not warn.
+! A DECLARE SIMD in an actual definition is fine and must not warn about
+! its effect.
 subroutine sub(i)
+!WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
 !$omp declare simd(sub) linear(i:1)
  integer :: i
  i = i + 1
@@ -3,6 +3,7 @@
 ! Test declare simd with uniform clause

 function add2(a,b,i,fact,alc) result(c)
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !$omp declare simd(add2) uniform(a,b,fact)
  integer :: i
  integer,pointer::alc
@@ -27,6 +28,7 @@ function bad_uniform(a,b,i) result(c)
  double precision :: a(*), b(*), c
  integer :: i
  double precision :: local
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !ERROR: Variable 'local' in UNIFORM clause must be a dummy argument of the enclosing procedure
  !$omp declare simd(bad_uniform) uniform(a,local)
  c = a(i) + b(i) + local
@@ -2,12 +2,15 @@

 module m

+!WARNING: DECLARE_SIMD directive is not implemented yet and will be ignored
 !ERROR: The name 'x' should refer to a procedure
 !$omp declare_simd(x)

+!WARNING: DECLARE_SIMD directive is not implemented yet and will be ignored
 !ERROR: DECLARE_SIMD directive should have at most one argument
 !$omp declare_simd(f00, f01)

+!WARNING: DECLARE_SIMD directive is not implemented yet and will be ignored
 !ERROR: The argument to the DECLARE_SIMD directive should be a procedure name
 !$omp declare_simd(v : integer)

@@ -20,7 +23,8 @@ subroutine f01
 end

 integer function f02
-!Ok, expect no diagnostics
+!Ok, expect no errors
+!WARNING: DECLARE_SIMD directive is not implemented yet and will be ignored
 !$omp declare_simd(f02)
 end

@@ -41,6 +41,7 @@ subroutine f02
 end

 subroutine f03
+!WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
 !WARNING: Directive spelling 'DECLARE_SIMD' is introduced in a later OpenMP version, try -fopenmp-version=60
  !$omp declare_simd
 end
@@ -19,16 +19,19 @@ end subroutine linear_clause_01
 subroutine linear_clause_02(arg_01, arg_02)
    !ERROR: The list item 'arg_01' specified without the REF 'linear-modifier' must be of INTEGER type
    !ERROR: List item 'arg_01' in LINEAR clause must be a scalar variable
+    !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
    !$omp declare simd linear(val(arg_01))
    real, intent(in) :: arg_01(:)

    !ERROR: If the `linear-modifier` is REF or UVAL, the list item 'arg_02' must be a dummy argument without the VALUE attribute
+    !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
    !$omp declare simd linear(uval(arg_02))
    integer, value, intent(in) :: arg_02

    !ERROR: If the `linear-modifier` is REF or UVAL, the list item 'var' must be a dummy argument without the VALUE attribute
    !ERROR: The list item `var` must be a dummy argument
    !ERROR: The list item `var` in a LINEAR clause must not be Cray Pointer or a variable with POINTER attribute
+    !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
    !$omp declare simd linear(uval(var))
    integer, pointer :: var
 end subroutine linear_clause_02
@@ -39,13 +42,16 @@ subroutine linear_clause_03(arg)
    !ERROR: The list item `arg` specified with the REF 'linear-modifier' must be polymorphic variable, assumed-shape array, or a variable with the `ALLOCATABLE` attribute
    !ERROR: List item 'arg' present at multiple LINEAR clauses
    !ERROR: 'arg' appears in more than one data-sharing clause on the same OpenMP directive
+    !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
    !$omp declare simd linear(ref(arg)) linear(arg)

    integer :: i
    common /cc/ i
+    !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
    !ERROR: The list item `i` must be a dummy argument
    !$omp declare simd linear(i)

+    !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
    !ERROR: 'cc' is a common block name and must not appear in a LINEAR clause
    !ERROR: The list item `i` must be a dummy argument
    !$omp declare simd linear(/cc/)
@@ -3,11 +3,13 @@
 subroutine f00(x)
  integer :: x
  !WARNING: The 'modifier(<list>)' syntax is deprecated in OpenMP v5.2, use '<list> : modifier' instead
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !$omp declare simd linear(uval(x))
 end

 subroutine f01(x)
  integer :: x
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !ERROR: An exclusive 'step-simple-modifier' modifier cannot be specified together with a modifier of a different type
  !$omp declare simd linear(uval(x) : 2)
 end
@@ -6,6 +6,7 @@ interface
  subroutine f(x, y)
    integer, allocatable :: x
    integer :: y
+    !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
    !WARNING: 'DECLARE SIMD' directive in an interface body has no effect [-Wopenmp-usage]
    !$omp declare simd(f) linear(ref(x) : 1) linear(uval(y))
  end
@@ -75,6 +75,7 @@ subroutine test_declare_simd_ref_array_valid(arr)
  implicit none
  integer, intent(in) :: arr(:)
  
+  !WARNING: DECLARE SIMD directive is not implemented yet and will be ignored
  !$omp declare simd linear(ref(arr))
  ! No error expected - REF modifier allows assumed-shape arrays
 end subroutine
@@ -9743,6 +9743,13 @@ LogicalResult OpenMPDialectLLVMIRTranslationInterface::convertOperation(
          .Case([&](omp::GroupprivateOp) {
            return convertOmpGroupprivate(*op, builder, moduleTranslation);
          })
+          .Case([&](omp::DeclareSimdOp) {
+            // TODO: Implement.
+            // DECLARE_SIMD can be ignored. There is warning emitted in
+            // semantic checks about the current situation, but not having an
+            // implementation should not prevent compilation.
+            return success();
+          })
          .Default([&](Operation *inst) {
            return inst->emitError()
                   << "not yet implemented: " << inst->getName();