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| author | Harald Anlauf <anlauf@gmx.de> | 2023-02-27 21:37:11 +0100 |
|---|---|---|
| committer | Harald Anlauf <anlauf@gmx.de> | 2023-02-27 22:30:29 +0100 |
| commit | 6cce953ebec274f1468d5d3a0697cf05bb43b8f6 (patch) | |
| tree | 0cb73689f4ede61e1c284024071ead1e17d0e6c6 /gcc | |
| parent | 8020c9c42349f51f75239b9d35a2be41848a97bd (diff) | |
| download | gcc-6cce953ebec274f1468d5d3a0697cf05bb43b8f6.zip gcc-6cce953ebec274f1468d5d3a0697cf05bb43b8f6.tar.gz gcc-6cce953ebec274f1468d5d3a0697cf05bb43b8f6.tar.bz2 | |
Fortran: fix corner case of IBITS intrinsic [PR108937]
gcc/fortran/ChangeLog:
PR fortran/108937
* trans-intrinsic.cc (gfc_conv_intrinsic_ibits): Handle corner case
LEN argument of IBITS equal to BITSIZE(I).
gcc/testsuite/ChangeLog:
PR fortran/108937
* gfortran.dg/ibits_2.f90: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/fortran/trans-intrinsic.cc | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gfortran.dg/ibits_2.f90 | 32 |
2 files changed, 42 insertions, 0 deletions
diff --git a/gcc/fortran/trans-intrinsic.cc b/gcc/fortran/trans-intrinsic.cc index 21eeb12..3cce9c0 100644 --- a/gcc/fortran/trans-intrinsic.cc +++ b/gcc/fortran/trans-intrinsic.cc @@ -6638,6 +6638,7 @@ gfc_conv_intrinsic_ibits (gfc_se * se, gfc_expr * expr) tree type; tree tmp; tree mask; + tree num_bits, cond; gfc_conv_intrinsic_function_args (se, expr, args, 3); type = TREE_TYPE (args[0]); @@ -6678,8 +6679,17 @@ gfc_conv_intrinsic_ibits (gfc_se * se, gfc_expr * expr) "in intrinsic IBITS", tmp1, tmp2, nbits); } + /* The Fortran standard allows (shift width) LEN <= BIT_SIZE(I), whereas + gcc requires a shift width < BIT_SIZE(I), so we have to catch this + special case. See also gfc_conv_intrinsic_ishft (). */ + num_bits = build_int_cst (TREE_TYPE (args[2]), TYPE_PRECISION (type)); + mask = build_int_cst (type, -1); mask = fold_build2_loc (input_location, LSHIFT_EXPR, type, mask, args[2]); + cond = fold_build2_loc (input_location, GE_EXPR, logical_type_node, args[2], + num_bits); + mask = fold_build3_loc (input_location, COND_EXPR, type, cond, + build_int_cst (type, 0), mask); mask = fold_build1_loc (input_location, BIT_NOT_EXPR, type, mask); tmp = fold_build2_loc (input_location, RSHIFT_EXPR, type, args[0], args[1]); diff --git a/gcc/testsuite/gfortran.dg/ibits_2.f90 b/gcc/testsuite/gfortran.dg/ibits_2.f90 new file mode 100644 index 0000000..2af5542 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/ibits_2.f90 @@ -0,0 +1,32 @@ +! { dg-do run } +! { dg-additional-options "-fcheck=bits" } +! PR fortran/108937 - Intrinsic IBITS(I,POS,LEN) fails when LEN equals +! to BIT_SIZE(I) +! Contributed by saitofuyuki@jamstec.go.jp + +program test_bits + implicit none + integer, parameter :: KT = kind (1) + integer, parameter :: lbits = bit_size (0_KT) + integer(kind=KT) :: x, y0, y1 + integer(kind=KT) :: p, l + + x = -1 + p = 0 + do l = 0, lbits + y0 = ibits (x, p, l) + y1 = ibits_1(x, p, l) + if (y0 /= y1) then + print *, l, y0, y1 + stop 1+l + end if + end do +contains + elemental integer(kind=KT) function ibits_1(I, POS, LEN) result(n) + !! IBITS(I, POS, LEN) = (I >> POS) & ~((~0) << LEN) + implicit none + integer(kind=KT),intent(in) :: I + integer, intent(in) :: POS, LEN + n = IAND (ISHFT(I, - POS), NOT(ISHFT(-1_KT, LEN))) + end function ibits_1 +end program test_bits |