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[flang] Control flow with empty select case blocks
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Authored by vdonaldson on Sep 7 2022, 9:36 PM.

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Details

Reviewers

jeanPerier
clementval

Summary

Fix control flow for empty select case blocks such as:

select case (2)
  case (1)
    print*, '1'
  case (2)
  ! print*, '2'
  case default
    print*, 'default'
end select

Diff Detail

Event Timeline

vdonaldson created this revision.Sep 7 2022, 9:36 PM

Herald added a project: Restricted Project. · View Herald TranscriptSep 7 2022, 9:36 PM

Herald added subscribers: mehdi_amini, jdoerfert. · View Herald Transcript

vdonaldson requested review of this revision.Sep 7 2022, 9:36 PM

vdonaldson added reviewers: jeanPerier, clementval.

Harbormaster completed remote builds in B185558: Diff 458638.Sep 7 2022, 10:00 PM

Looks good

This revision is now accepted and ready to land.Sep 8 2022, 12:41 AM

LGTM

https://reviews.llvm.org/D133470

Revision Contents

Path

Size

flang/

lib/

Lower/

Bridge.cpp

4 lines

test/

Lower/

select-case-statement.f90

59 lines

Diff 458638

flang/lib/Lower/Bridge.cpp

Show First 20 Lines • Show All 2,674 Lines • ▼ Show 20 Lines	if (unstructuredContext && blockIsUnterminated()) {
// Exit from an unstructured IF or SELECT construct block.		// Exit from an unstructured IF or SELECT construct block.
Fortran::lower::pft::Evaluation *successor{};		Fortran::lower::pft::Evaluation *successor{};
if (eval.isActionStmt())		if (eval.isActionStmt())
successor = eval.controlSuccessor;		successor = eval.controlSuccessor;
else if (eval.isConstruct() &&		else if (eval.isConstruct() &&
eval.getLastNestedEvaluation()		eval.getLastNestedEvaluation()
.lexicalSuccessor->isIntermediateConstructStmt())		.lexicalSuccessor->isIntermediateConstructStmt())
successor = eval.constructExit;		successor = eval.constructExit;
		else if (eval.isConstructStmt() &&
		eval.lexicalSuccessor == eval.controlSuccessor)
		// empty construct block
		successor = eval.parentConstruct->constructExit;
if (successor && successor->block)		if (successor && successor->block)
genFIRBranch(successor->block);		genFIRBranch(successor->block);
}		}
}		}

void mapCPtrArgByValue(const Fortran::semantics::Symbol &sym,		void mapCPtrArgByValue(const Fortran::semantics::Symbol &sym,
mlir::Value val) {		mlir::Value val) {
mlir::Type symTy = Fortran::lower::translateSymbolToFIRType(*this, sym);		mlir::Type symTy = Fortran::lower::translateSymbolToFIRType(*this, sym);
▲ Show 20 Lines • Show All 681 Lines • Show Last 20 Lines

flang/test/Lower/select-case-statement.f90

Show First 20 Lines • Show All 279 Lines • ▼ Show 20 Lines	subroutine scharacter2(s)
! CHECK: br ^bb3		! CHECK: br ^bb3
! CHECK: ^bb3: // pred: ^bb2		! CHECK: ^bb3: // pred: ^bb2
n = -2		n = -2
select case(trim(s))		select case(trim(s))
end select		end select
print*, n		print*, n
end subroutine		end subroutine

		! CHECK-LABEL: func @_QPsempty
		! empty select case blocks
		subroutine sempty(n)
		! CHECK: %[[selectI1:[0-9]+]] = fir.load %arg0 : !fir.ref<i32>
		! CHECK: fir.select_case %[[selectI1]] : i32 [#fir.point, %c1{{.}}, ^bb1, #fir.point, %c2{{.}}, ^bb2, unit, ^bb3]
		! CHECK: ^bb1: // pred: ^bb0
		! CHECK: fir.call @_FortranAioBeginExternalListOutput
		! CHECK: br ^bb4
		! CHECK: ^bb2: // pred: ^bb0
		! CHECK: br ^bb4
		! CHECK: ^bb3: // pred: ^bb0
		! CHECK: fir.call @_FortranAioBeginExternalListOutput
		! CHECK: br ^bb4
		select case (n)
		case (1)
		print*, n, 'i:case 1'
		case (2)
		! print*, n, 'i:case 2'
		case default
		print*, n, 'i:case default'
		end select
		! CHECK: ^bb4: // 3 preds: ^bb1, ^bb2, ^bb3
		! CHECK: %[[cmpC1:[0-9]+]] = fir.call @_FortranACharacterCompareScalar1
		! CHECK: %[[selectC1:[0-9]+]] = arith.cmpi eq, %[[cmpC1]], %c0{{.*}} : i32
		! CHECK: cond_br %[[selectC1]], ^bb6, ^bb5
		! CHECK: ^bb5: // pred: ^bb4
		! CHECK: %[[cmpC2:[0-9]+]] = fir.call @_FortranACharacterCompareScalar1
		! CHECK: %[[selectC2:[0-9]+]] = arith.cmpi eq, %[[cmpC2]], %c0{{.*}} : i32
		! CHECK: cond_br %[[selectC2]], ^bb8, ^bb7
		! CHECK: ^bb6: // pred: ^bb4
		! CHECK: fir.call @_FortranAioBeginExternalListOutput
		! print*, n, 'c:case 2'
		! CHECK: br ^bb10
		! CHECK: ^bb7: // pred: ^bb5
		! CHECK: br ^bb9
		! CHECK: ^bb8: // pred: ^bb5
		! CHECK: br ^bb10
		! CHECK: ^bb9: // pred: ^bb7
		! CHECK: fir.call @_FortranAioBeginExternalListOutput
		! CHECK: br ^bb10
		! CHECK: ^bb10: // 3 preds: ^bb6, ^bb8, ^bb9
		select case (char(ichar('0')+n))
		case ('1')
		print*, n, 'c:case 1'
		case ('2')
		! print*, n, 'c:case 2'
		case default
		print*, n, 'c:case default'
		end select
		! CHECK: return
		end subroutine


! CHECK-LABEL: func @_QPswhere		! CHECK-LABEL: func @_QPswhere
subroutine swhere(num)		subroutine swhere(num)
implicit none		implicit none

integer, intent(in) :: num		integer, intent(in) :: num
real, dimension(1) :: array		real, dimension(1) :: array

array = 0.0		array = 0.0
▲ Show 20 Lines • Show All 93 Lines • ▼ Show 20 Lines	program p

print*		print*
call scharacter2('99 ') ! expected output: 9 -2		call scharacter2('99 ') ! expected output: 9 -2
call scharacter2('22 ') ! expected output: 9 -2		call scharacter2('22 ') ! expected output: 9 -2
call scharacter2('. ') ! expected output: 9 -2		call scharacter2('. ') ! expected output: 9 -2
call scharacter2(' ') ! expected output: 9 -2		call scharacter2(' ') ! expected output: 9 -2

print*		print*
		call sempty(0) ! expected output: 0 i:case default 0; c:case default
		call sempty(1) ! expected output: 1 i:case 1; 1 c:case 1
		call sempty(2) ! no output
		call sempty(3) ! expected output: 3 i:case default; 3 c:case default

		print*
call swhere(1) ! expected output: 42.		call swhere(1) ! expected output: 42.
call sforall(1) ! expected output: 42.		call sforall(1) ! expected output: 42.
end		end