public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r11-8961] Fortran - simplify length of substring with constant bounds
@ 2021-09-05 20:19 Harald Anlauf
0 siblings, 0 replies; only message in thread
From: Harald Anlauf @ 2021-09-05 20:19 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:c94755c7734c6aac9e114fb69ca23aed524e2450
commit r11-8961-gc94755c7734c6aac9e114fb69ca23aed524e2450
Author: Harald Anlauf <anlauf@gmx.de>
Date: Thu Aug 19 21:00:45 2021 +0200
Fortran - simplify length of substring with constant bounds
gcc/fortran/ChangeLog:
PR fortran/100950
* simplify.c (substring_has_constant_len): New.
(gfc_simplify_len): Handle case of substrings with constant
bounds.
gcc/testsuite/ChangeLog:
PR fortran/100950
* gfortran.dg/pr100950.f90: New test.
(cherry picked from commit d881460deb1f0bdfc3e8fa2d391a03a9763cbff4)
Diff:
---
gcc/fortran/simplify.c | 75 +++++++++++++++++++++++++++++++++-
gcc/testsuite/gfortran.dg/pr100950.f90 | 53 ++++++++++++++++++++++++
2 files changed, 127 insertions(+), 1 deletion(-)
diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index c27b47aa98f..492867e12cb 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -4512,6 +4512,78 @@ gfc_simplify_leadz (gfc_expr *e)
}
+/* Check for constant length of a substring. */
+
+static bool
+substring_has_constant_len (gfc_expr *e)
+{
+ gfc_ref *ref;
+ HOST_WIDE_INT istart, iend, length;
+ bool equal_length = false;
+
+ if (e->ts.type != BT_CHARACTER)
+ return false;
+
+ for (ref = e->ref; ref; ref = ref->next)
+ if (ref->type != REF_COMPONENT && ref->type != REF_ARRAY)
+ break;
+
+ if (!ref
+ || ref->type != REF_SUBSTRING
+ || !ref->u.ss.start
+ || ref->u.ss.start->expr_type != EXPR_CONSTANT
+ || !ref->u.ss.end
+ || ref->u.ss.end->expr_type != EXPR_CONSTANT
+ || !ref->u.ss.length)
+ return false;
+
+ /* For non-deferred strings the given length shall be constant. */
+ if (!e->ts.deferred
+ && (!ref->u.ss.length->length
+ || ref->u.ss.length->length->expr_type != EXPR_CONSTANT))
+ return false;
+
+ /* Basic checks on substring starting and ending indices. */
+ if (!gfc_resolve_substring (ref, &equal_length))
+ return false;
+
+ istart = gfc_mpz_get_hwi (ref->u.ss.start->value.integer);
+ iend = gfc_mpz_get_hwi (ref->u.ss.end->value.integer);
+
+ if (istart <= iend)
+ {
+ if (istart < 1)
+ {
+ gfc_error ("Substring start index (" HOST_WIDE_INT_PRINT_DEC
+ ") at %L below 1",
+ istart, &ref->u.ss.start->where);
+ return false;
+ }
+
+ /* For deferred strings use end index as proxy for length. */
+ if (e->ts.deferred)
+ length = iend;
+ else
+ length = gfc_mpz_get_hwi (ref->u.ss.length->length->value.integer);
+ if (iend > length)
+ {
+ gfc_error ("Substring end index (" HOST_WIDE_INT_PRINT_DEC
+ ") at %L exceeds string length",
+ iend, &ref->u.ss.end->where);
+ return false;
+ }
+ length = iend - istart + 1;
+ }
+ else
+ length = 0;
+
+ /* Fix substring length. */
+ e->value.character.length = length;
+
+ return true;
+}
+
+
gfc_expr *
gfc_simplify_len (gfc_expr *e, gfc_expr *kind)
{
@@ -4521,7 +4593,8 @@ gfc_simplify_len (gfc_expr *e, gfc_expr *kind)
if (k == -1)
return &gfc_bad_expr;
- if (e->expr_type == EXPR_CONSTANT)
+ if (e->expr_type == EXPR_CONSTANT
+ || substring_has_constant_len (e))
{
result = gfc_get_constant_expr (BT_INTEGER, k, &e->where);
mpz_set_si (result->value.integer, e->value.character.length);
diff --git a/gcc/testsuite/gfortran.dg/pr100950.f90 b/gcc/testsuite/gfortran.dg/pr100950.f90
new file mode 100644
index 00000000000..cb9d126bc18
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr100950.f90
@@ -0,0 +1,53 @@
+! { dg-do run }
+! { dg-additional-options "-fdump-tree-original" }
+! PR fortran/100950 - ICE in output_constructor_regular_field, at varasm.c:5514
+
+program p
+ character(8), parameter :: u = "123"
+ character(8) :: x = "", s
+ character(2) :: w(2) = [character(len(x(3:4))) :: 'a','b' ]
+ character(*), parameter :: y(*) = [character(len(u(3:4))) :: 'a','b' ]
+ character(*), parameter :: z(*) = [character(len(x(3:4))) :: 'a','b' ]
+ character(*), parameter :: t(*) = [character(len(x( :2))) :: 'a','b' ]
+ character(*), parameter :: v(*) = [character(len(x(7: ))) :: 'a','b' ]
+ type t_
+ character(len=5) :: s
+ character(len=8) :: t(4)
+ character(len=8), pointer :: u(:)
+ character(len=:), allocatable :: str
+ character(len=:), allocatable :: str2(:)
+ end type t_
+ type(t_) :: q, r(1)
+ integer, parameter :: lq = len (q%s(3:4)), lr = len (r%s(3:4))
+ integer, parameter :: l1 = len (q %t(1)(3:4))
+ integer, parameter :: l2 = len (q %t(:)(3:4))
+ integer, parameter :: l3 = len (q %str (3:4))
+ integer, parameter :: l4 = len (r(:)%t(1)(3:4))
+ integer, parameter :: l5 = len (r(1)%t(:)(3:4))
+ integer, parameter :: l6 = len (r(1)%str (3:4))
+ integer, parameter :: l7 = len (r(1)%str2(1)(3:4))
+ integer, parameter :: l8 = len (r(1)%str2(:)(3:4))
+
+ if (len (y) /= 2) stop 1
+ if (len (z) /= 2) stop 2
+ if (any (w /= y)) stop 3
+ if (len ([character(len(u(3:4))) :: 'a','b' ]) /= 2) stop 4
+ if (len ([character(len(x(3:4))) :: 'a','b' ]) /= 2) stop 5
+ if (any ([character(len(x(3:4))) :: 'a','b' ] /= y)) stop 6
+ write(s,*) [character(len(x(3:4))) :: 'a','b' ]
+ if (s /= " a b ") stop 7
+ if (len (t) /= 2) stop 8
+ if (len (v) /= 2) stop 9
+ if (lq /= 2 .or. lr /= 2) stop 10
+ if (l1 /= 2 .or. l2 /= 2 .or. l4 /= 2 .or. l5 /= 2) stop 11
+ if (l3 /= 2 .or. l6 /= 2 .or. l7 /= 2 .or. l8 /= 2) stop 12
+
+ block
+ integer, parameter :: l9 = len (r(1)%u(:)(3:4))
+ if (l9 /= 2) stop 13
+ end block
+end
+
+! { dg-final { scan-tree-dump-times "_gfortran_stop_numeric" 2 "original" } }
+! { dg-final { scan-tree-dump "_gfortran_stop_numeric \\(3, 0\\);" "original" } }
+! { dg-final { scan-tree-dump "_gfortran_stop_numeric \\(7, 0\\);" "original" } }
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2021-09-05 20:19 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-05 20:19 [gcc r11-8961] Fortran - simplify length of substring with constant bounds Harald Anlauf
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).