[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 anlauf at gcc dot gnu.org changed: What|Removed |Added Target Milestone|--- |10.5 Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #12 from anlauf at gcc dot gnu.org --- Fixed for all open branches. Closing. Thanks for the report!
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 --- Comment #11 from CVS Commits --- The releases/gcc-10 branch has been updated by Harald Anlauf : https://gcc.gnu.org/g:e6db08d9183b80b0ada5122fae79412544279f56 commit r10-10877-ge6db08d9183b80b0ada5122fae79412544279f56 Author: Harald Anlauf Date: Tue Jun 21 23:20:18 2022 +0200 Fortran: fix simplification of INDEX(str1,str2) [PR105691] gcc/fortran/ChangeLog: PR fortran/105691 * simplify.c (gfc_simplify_index): Replace old simplification code by the equivalent of the runtime library implementation. Use HOST_WIDE_INT instead of int for string index, length variables. gcc/testsuite/ChangeLog: PR fortran/105691 * gfortran.dg/index_6.f90: New test. (cherry picked from commit ff35dbc02092fbcd3d814fcd9fe8e871c3f741fd)
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 --- Comment #10 from CVS Commits --- The releases/gcc-11 branch has been updated by Harald Anlauf : https://gcc.gnu.org/g:614d9e76b71df6c5ad42f2b9c2a8156e8b3ebd35 commit r11-10102-g614d9e76b71df6c5ad42f2b9c2a8156e8b3ebd35 Author: Harald Anlauf Date: Tue Jun 21 23:20:18 2022 +0200 Fortran: fix simplification of INDEX(str1,str2) [PR105691] gcc/fortran/ChangeLog: PR fortran/105691 * simplify.c (gfc_simplify_index): Replace old simplification code by the equivalent of the runtime library implementation. Use HOST_WIDE_INT instead of int for string index, length variables. gcc/testsuite/ChangeLog: PR fortran/105691 * gfortran.dg/index_6.f90: New test. (cherry picked from commit ff35dbc02092fbcd3d814fcd9fe8e871c3f741fd)
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 --- Comment #9 from CVS Commits --- The releases/gcc-12 branch has been updated by Harald Anlauf : https://gcc.gnu.org/g:26ea506a1e8719f8b1f559e70bee9f5d3392eb37 commit r12-8530-g26ea506a1e8719f8b1f559e70bee9f5d3392eb37 Author: Harald Anlauf Date: Tue Jun 21 23:20:18 2022 +0200 Fortran: fix simplification of INDEX(str1,str2) [PR105691] gcc/fortran/ChangeLog: PR fortran/105691 * simplify.cc (gfc_simplify_index): Replace old simplification code by the equivalent of the runtime library implementation. Use HOST_WIDE_INT instead of int for string index, length variables. gcc/testsuite/ChangeLog: PR fortran/105691 * gfortran.dg/index_6.f90: New test. (cherry picked from commit ff35dbc02092fbcd3d814fcd9fe8e871c3f741fd)
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 --- Comment #8 from anlauf at gcc dot gnu.org --- Fixed on mainline so far.
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 --- Comment #7 from CVS Commits --- The master branch has been updated by Harald Anlauf : https://gcc.gnu.org/g:ff35dbc02092fbcd3d814fcd9fe8e871c3f741fd commit r13-1277-gff35dbc02092fbcd3d814fcd9fe8e871c3f741fd Author: Harald Anlauf Date: Tue Jun 21 23:20:18 2022 +0200 Fortran: fix simplification of INDEX(str1,str2) [PR105691] gcc/fortran/ChangeLog: PR fortran/105691 * simplify.cc (gfc_simplify_index): Replace old simplification code by the equivalent of the runtime library implementation. Use HOST_WIDE_INT instead of int for string index, length variables. gcc/testsuite/ChangeLog: PR fortran/105691 * gfortran.dg/index_6.f90: New test.
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 --- Comment #6 from Steve Kargl --- On Tue, Jun 21, 2022 at 09:28:27PM +, anlauf at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 > > --- Comment #5 from anlauf at gcc dot gnu.org --- > Submitted version: https://gcc.gnu.org/pipermail/fortran/2022-June/057940.html > Harald, looks like a straight forward translation of the library algorithm. OK to commit.
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 --- Comment #5 from anlauf at gcc dot gnu.org --- Submitted version: https://gcc.gnu.org/pipermail/fortran/2022-June/057940.html
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691 anlauf at gcc dot gnu.org changed: What|Removed |Added Status|NEW |ASSIGNED CC||anlauf at gcc dot gnu.org Assignee|unassigned at gcc dot gnu.org |anlauf at gcc dot gnu.org --- Comment #4 from anlauf at gcc dot gnu.org --- (In reply to kargl from comment #3) > There is no need to special case the substring length of 1 case with my > suggested patch. Here's an update to eliminate the special case. Frankly speaking, gfc_simplify_index is a mess. The library code is a relief. I'd take that as reference. Thus taking.
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691
--- Comment #3 from kargl at gcc dot gnu.org ---
There is no need to special case the substring length of 1 case with my
suggested patch. Here's an update to eliminate the special case.
diff --git a/gcc/fortran/simplify.cc b/gcc/fortran/simplify.cc
index 233cc42137f..fa9938d6a1e 100644
--- a/gcc/fortran/simplify.cc
+++ b/gcc/fortran/simplify.cc
@@ -3589,49 +3589,31 @@ gfc_simplify_index (gfc_expr *x, gfc_expr *y, gfc_expr
*b, gfc_expr *kind)
mpz_set_si (result->value.integer, len + 1);
return result;
}
- else if (lensub == 1)
+ else
{
- for (i = 0; i < len; i++)
+ /* Start at the tail of the string, offset by the length of the
+substring, and search for a match moving towards the head of
+string. */
+ for (i = len - lensub; i >= 0; i--)
{
- for (j = 0; j < lensub; j++)
+ /* If the first character does not match, then the rest of the
+string cannot match. */
+ if (x->value.character.string[i]
+ == y->value.character.string[0])
{
- if (y->value.character.string[j]
- == x->value.character.string[len - i])
+
+ /* Compare substring to starting location in string. */
+ for (j = 0, count = 0; j < lensub; j++, count++)
{
- index = len - i + 1;
- goto done;
+ if (x->value.character.string[i + j]
+ != y->value.character.string[j])
+ break;
}
- }
- }
- }
- else
- {
- for (i = 0; i < len; i++)
- {
- for (j = 0; j < lensub; j++)
- {
- if (y->value.character.string[j]
- == x->value.character.string[len - i])
+
+ if (count == lensub)
{
- start = len - i;
- if (start <= len - lensub)
- {
- count = 0;
- for (k = 0; k < lensub; k++)
- if (y->value.character.string[k]
- == x->value.character.string[k + start])
- count++;
-
- if (count == lensub)
- {
- index = start + 1;
- goto done;
- }
- }
- else
- {
- continue;
- }
+ index = i + 1;
+ goto done;
}
}
}
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691
kargl at gcc dot gnu.org changed:
What|Removed |Added
Last reconfirmed||2022-05-22
CC||kargl at gcc dot gnu.org
Ever confirmed|0 |1
Priority|P3 |P4
Status|UNCONFIRMED |NEW
--- Comment #2 from kargl at gcc dot gnu.org ---
There is some torched logic looking for the substring, which can never find it.
diff --git a/gcc/fortran/simplify.cc b/gcc/fortran/simplify.cc
index 233cc42137f..16b231f5707 100644
--- a/gcc/fortran/simplify.cc
+++ b/gcc/fortran/simplify.cc
@@ -3606,32 +3606,29 @@ gfc_simplify_index (gfc_expr *x, gfc_expr *y, gfc_expr
*b, gfc_expr *kind)
}
else
{
- for (i = 0; i < len; i++)
+ /* Start at the tail of the string, offset by the length of the
+substring, and search for a match moving towards the head of
+string. */
+ for (i = len - lensub; i >= 0; i--)
{
- for (j = 0; j < lensub; j++)
+ /* If the first character does not match, then the rest of the
+string cannot match. */
+ if (x->value.character.string[i]
+ == y->value.character.string[0])
{
- if (y->value.character.string[j]
- == x->value.character.string[len - i])
+
+ /* Compare substring to starting location in string. */
+ for (j = 0, count = 0; j < lensub; j++, count++)
{
- start = len - i;
- if (start <= len - lensub)
- {
- count = 0;
- for (k = 0; k < lensub; k++)
- if (y->value.character.string[k]
- == x->value.character.string[k + start])
- count++;
-
- if (count == lensub)
- {
- index = start + 1;
- goto done;
- }
- }
- else
- {
- continue;
- }
+ if (x->value.character.string[i + j]
+ != y->value.character.string[j])
+ break;
+ }
+
+ if (count == lensub)
+ {
+ index = i + 1;
+ goto done;
}
}
}
[Bug fortran/105691] Incorrect calculation of INDEX(str1,str2) at compile time
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105691
--- Comment #1 from mecej4 ---
When a program contains an expression that involves the INDEX intrinsic
function, and it is possible to calculate its result value at compile time, the
computed value is sometimes incorrect.
program main
i = index("fortran.f90", "fortran", back=.true.) ! It should get '1'
call prnt(i)
contains
subroutine prnt(i)
integer i
print *,'i = ',i
end subroutine
end program
The program prints '0' instead of '1'. Looking at the assembly code generated
shows that the argument value in the argument I passed to PRNT() is zero.
