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re PR fortran/90577 (FAIL: gfortran.dg/lrshift_1.f90 with -O(2|3) and -flto)

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2019-06-14  Harald Anlauf  <anlauf@gmx.de>

	PR fortran/90577
	PR fortran/90578
	* trans-intrinsic.c (gfc_conv_intrinsic_shift): Properly
	distinguish logical/arithmetic shifts.
	* intrinsic.texi: Update documentation for SHIFTR/SHIFTL/SHIFTA
	(Fortran 2008) and LSHIFT/RSHIFT (GNU extensions).

	PR fortran/90577
	PR fortran/90578
	* gfortran.dg/lrshift_1.f90: Adjust testcase.
	* gfortran.dg/shiftalr_3.f90: New testcase.

From-SVN: r272309
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Harald Anlauf 2019-06-14 18:41:20 +00:00 committed by Harald Anlauf
parent a8566e938c
commit d0442491d5
6 changed files with 97 additions and 24 deletions
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9
gcc/fortran/ChangeLog
View File

@ -1,3 +1,12 @@
2019-06-14 Harald Anlauf <anlauf@gmx.de>
PR fortran/90577
PR fortran/90578
* trans-intrinsic.c (gfc_conv_intrinsic_shift): Properly
distinguish logical/arithmetic shifts.
* intrinsic.texi: Update documentation for SHIFTR/SHIFTL/SHIFTA
(Fortran 2008) and LSHIFT/RSHIFT (GNU extensions).
2019-06-14 Steven G. Kargl <kargl@gcc.gnu.org>
PR fortran/89646

46
gcc/fortran/intrinsic.texi
View File

@ -9689,10 +9689,10 @@ The return value is a @code{INTEGER(4)} variable.
@table @asis
@item @emph{Description}:
@code{LSHIFT} returns a value corresponding to @var{I} with all of the
bits shifted left by @var{SHIFT} places. If the absolute value of
@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
Bits shifted out from the left end are lost; zeros are shifted in from
the opposite end.
bits shifted left by @var{SHIFT} places. @var{SHIFT} shall be
nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
the result value is undefined. Bits shifted out from the left end are
lost; zeros are shifted in from the opposite end.
This function has been superseded by the @code{ISHFT} intrinsic, which
is standard in Fortran 95 and later, and the @code{SHIFTL} intrinsic,
@ -12244,11 +12244,12 @@ The value returned is equal to
@table @asis
@item @emph{Description}:
@code{RSHIFT} returns a value corresponding to @var{I} with all of the
bits shifted right by @var{SHIFT} places. If the absolute value of
@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
Bits shifted out from the right end are lost. The fill is arithmetic: the
bits shifted in from the left end are equal to the leftmost bit, which in
two's complement representation is the sign bit.
bits shifted right by @var{SHIFT} places. @var{SHIFT} shall be
nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
the result value is undefined. Bits shifted out from the right end
are lost. The fill is arithmetic: the bits shifted in from the left
end are equal to the leftmost bit, which in two's complement
representation is the sign bit.
This function has been superseded by the @code{SHIFTA} intrinsic, which
is standard in Fortran 2008 and later.
@ -12783,11 +12784,12 @@ END PROGRAM
@table @asis
@item @emph{Description}:
@code{SHIFTA} returns a value corresponding to @var{I} with all of the
bits shifted right by @var{SHIFT} places. If the absolute value of
@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
Bits shifted out from the right end are lost. The fill is arithmetic: the
bits shifted in from the left end are equal to the leftmost bit, which in
two's complement representation is the sign bit.
bits shifted right by @var{SHIFT} places. @var{SHIFT} that be
nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
the result value is undefined. Bits shifted out from the right end
are lost. The fill is arithmetic: the bits shifted in from the left
end are equal to the leftmost bit, which in two's complement
representation is the sign bit.
@item @emph{Standard}:
Fortran 2008 and later
@ -12823,10 +12825,10 @@ The return value is of type @code{INTEGER} and of the same kind as
@table @asis
@item @emph{Description}:
@code{SHIFTL} returns a value corresponding to @var{I} with all of the
bits shifted left by @var{SHIFT} places. If the absolute value of
@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
Bits shifted out from the left end are lost, and bits shifted in from
the right end are set to 0.
bits shifted left by @var{SHIFT} places. @var{SHIFT} shall be
nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
the result value is undefined. Bits shifted out from the left end are
lost, and bits shifted in from the right end are set to 0.
@item @emph{Standard}:
Fortran 2008 and later
@ -12862,10 +12864,10 @@ The return value is of type @code{INTEGER} and of the same kind as
@table @asis
@item @emph{Description}:
@code{SHIFTR} returns a value corresponding to @var{I} with all of the
bits shifted right by @var{SHIFT} places. If the absolute value of
@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
Bits shifted out from the right end are lost, and bits shifted in from
the left end are set to 0.
bits shifted right by @var{SHIFT} places. @var{SHIFT} shall be
nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
the result value is undefined. Bits shifted out from the right end
are lost, and bits shifted in from the left end are set to 0.
@item @emph{Standard}:
Fortran 2008 and later

15
gcc/fortran/trans-intrinsic.c
View File

@ -6346,6 +6346,7 @@ gfc_conv_intrinsic_shift (gfc_se * se, gfc_expr * expr, bool right_shift,
bool arithmetic)
{
tree args[2], type, num_bits, cond;
tree bigshift;
gfc_conv_intrinsic_function_args (se, expr, args, 2);
@ -6365,6 +6366,18 @@ gfc_conv_intrinsic_shift (gfc_se * se, gfc_expr * expr, bool right_shift,
if (!arithmetic)
se->expr = fold_convert (type, se->expr);
if (!arithmetic)
bigshift = build_int_cst (type, 0);
else
{
tree nonneg = fold_build2_loc (input_location, GE_EXPR,
logical_type_node, args[0],
build_int_cst (TREE_TYPE (args[0]), 0));
bigshift = fold_build3_loc (input_location, COND_EXPR, type, nonneg,
build_int_cst (type, 0),
build_int_cst (type, -1));
}
/* The Fortran standard allows shift widths <= BIT_SIZE(I), whereas
gcc requires a shift width < BIT_SIZE(I), so we have to catch this
special case. */
@ -6373,7 +6386,7 @@ gfc_conv_intrinsic_shift (gfc_se * se, gfc_expr * expr, bool right_shift,
args[1], num_bits);
se->expr = fold_build3_loc (input_location, COND_EXPR, type, cond,
build_int_cst (type, 0), se->expr);
bigshift, se->expr);
}
/* ISHFT (I, SHIFT) = (abs (shift) >= BIT_SIZE (i))

7
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,10 @@
2019-06-14 Harald Anlauf <anlauf@gmx.de>
PR fortran/90577
PR fortran/90578
* gfortran.dg/lrshift_1.f90: Adjust testcase.
* gfortran.dg/shiftalr_3.f90: New testcase.
2019-06-14 Steven G. Kargl <kargl@gcc.gnu.org>
PR fortran/89646

2
gcc/testsuite/gfortran.dg/lrshift_1.f90
View File

@ -10,7 +10,7 @@ program test_rshift_lshift
1, 2, 127, 128, 129, huge(i)/2, huge(i) /)
do n = 1, size(i)
do j = -30, 30
do j = 0, 31
if (lshift(i(n),j) /= c_lshift(i(n),j)) STOP 1
if (rshift(i(n),j) /= c_rshift(i(n),j)) STOP 2
end do

42
gcc/testsuite/gfortran.dg/shiftalr_3.f90 Normal file
View File

@ -0,0 +1,42 @@
! { dg-do run }
!
! Test shift intrinsics when the SHIFT argument equals BIT_SIZE(arg1).
program test
implicit none
! Test compile-time simplifications
if (ishft (-1, 32) /= 0) stop 1 ! 0 -> simplify_shift OK
if (ishft (-1,-32) /= 0) stop 2 ! 0 -> simplify_shift OK
if (shiftl (-1, 32) /= 0) stop 3 ! 0 -> simplify_shift OK
if (shiftr (-1, 32) /= 0) stop 4 ! 0 -> simplify_shift OK
if (shifta (-1, 32) /= -1) stop 5 ! -1 -> simplify_shift OK
if (rshift (-1, 32) /= -1) stop 6 ! -1 -> simplify_shift OK
if (lshift (-1, 32) /= 0) stop 7 ! 0 -> simplify_shift OK
! Test run-time
call foo (-1)
contains
subroutine foo (n)
integer(4) :: i, j, k, n
integer, parameter :: bb = bit_size (n)
! Test code generated by gfc_conv_intrinsic_ishft
i = ishft (n, bb) ! Logical (left) shift (Fortran 2008)
j = ishft (n,-bb) ! Logical (right) shift (Fortran 2008)
if (i /= 0) stop 11
if (j /= 0) stop 12
! Test code generated by gfc_conv_intrinsic_shift:
i = shiftl (n, bb) ! Logical left shift (Fortran 2008)
j = shiftr (n, bb) ! Logical right shift (Fortran 2008)
k = shifta (n, bb) ! Arithmetic right shift (Fortran 2008)
if (i /= 0) stop 13
if (j /= 0) stop 14
if (k /= -1) stop 15
i = lshift (n, bb) ! Logical left shift (GNU extension)
j = rshift (n, bb) ! Arithmetic right shift (GNU extension)
if (i /= 0) stop 16
if (j /= -1) stop 17
do i = bb-1,bb
if (shifta (n, i) /= -1) stop 18
if (rshift (n, i) /= -1) stop 19
end do
end subroutine foo
end program test