diff options
| -rw-r--r-- | gcc/fortran/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/fortran/frontend-passes.c | 80 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gfortran.dg/do_while_1.f90 | 10 |
4 files changed, 102 insertions, 0 deletions
diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog index 96af79e04f8..836967d7a4b 100644 --- a/gcc/fortran/ChangeLog +++ b/gcc/fortran/ChangeLog @@ -1,3 +1,10 @@ +2011-09-11 Thomas Koenig <tkoenig@gcc.gnu.org> + + PR fortran/50327 + * frontend-passes.c (dummy_expr_callback): New function. + (convert_do_while): New function. + (optimize_namespace): Call code walker to convert do while loops. + 2011-09-11 Janus Weil <janus@gcc.gnu.org> PR fortran/35831 diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c index ab8e9e0607b..16053e0742a 100644 --- a/gcc/fortran/frontend-passes.c +++ b/gcc/fortran/frontend-passes.c @@ -407,6 +407,85 @@ cfe_code (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED, return 0; } +/* Dummy function for expression call back, for use when we + really don't want to do any walking. */ + +static int +dummy_expr_callback (gfc_expr **e ATTRIBUTE_UNUSED, int *walk_subtrees, + void *data ATTRIBUTE_UNUSED) +{ + *walk_subtrees = 0; + return 0; +} + +/* Code callback function for converting + do while(a) + end do + into the equivalent + do + if (.not. a) exit + end do + This is because common function elimination would otherwise place the + temporary variables outside the loop. */ + +static int +convert_do_while (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + gfc_code *co = *c; + gfc_code *c_if1, *c_if2, *c_exit; + gfc_code *loopblock; + gfc_expr *e_not, *e_cond; + + if (co->op != EXEC_DO_WHILE) + return 0; + + if (co->expr1 == NULL || co->expr1->expr_type == EXPR_CONSTANT) + return 0; + + e_cond = co->expr1; + + /* Generate the condition of the if statement, which is .not. the original + statement. */ + e_not = gfc_get_expr (); + e_not->ts = e_cond->ts; + e_not->where = e_cond->where; + e_not->expr_type = EXPR_OP; + e_not->value.op.op = INTRINSIC_NOT; + e_not->value.op.op1 = e_cond; + + /* Generate the EXIT statement. */ + c_exit = XCNEW (gfc_code); + c_exit->op = EXEC_EXIT; + c_exit->ext.which_construct = co; + c_exit->loc = co->loc; + + /* Generate the IF statement. */ + c_if2 = XCNEW (gfc_code); + c_if2->op = EXEC_IF; + c_if2->expr1 = e_not; + c_if2->next = c_exit; + c_if2->loc = co->loc; + + /* ... plus the one to chain it to. */ + c_if1 = XCNEW (gfc_code); + c_if1->op = EXEC_IF; + c_if1->block = c_if2; + c_if1->loc = co->loc; + + /* Make the DO WHILE loop into a DO block by replacing the condition + with a true constant. */ + co->expr1 = gfc_get_logical_expr (gfc_default_integer_kind, &co->loc, true); + + /* Hang the generated if statement into the loop body. */ + + loopblock = co->block->next; + co->block->next = c_if1; + c_if1->next = loopblock; + + return 0; +} + /* Optimize a namespace, including all contained namespaces. */ static void @@ -415,6 +494,7 @@ optimize_namespace (gfc_namespace *ns) current_ns = ns; + gfc_code_walker (&ns->code, convert_do_while, dummy_expr_callback, NULL); gfc_code_walker (&ns->code, cfe_code, cfe_expr_0, NULL); gfc_code_walker (&ns->code, optimize_code, optimize_expr, NULL); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 2a5096970bc..f3cb48705ac 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2011-09-11 Thomas Koenig <tkoenig@gcc.gnu.org> + + PR fortran/50327 + * gfortran.dg/do_while_1.f90: New test. + 2011-09-11 Janus Weil <janus@gcc.gnu.org> PR fortran/35831 diff --git a/gcc/testsuite/gfortran.dg/do_while_1.f90 b/gcc/testsuite/gfortran.dg/do_while_1.f90 new file mode 100644 index 00000000000..0a22ff37cf0 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/do_while_1.f90 @@ -0,0 +1,10 @@ +! { dg-do run } +! PR 50327 - this used to cause an endless loop because +! of wrong fron-end optimization. +program main + real :: tmp + tmp = 0. + do while (abs(tmp) < 10. .and. abs(tmp) < 20.) + tmp = tmp + 1. + end do +end program main |