From 6ed825558ec5df100d84c284c52618ec397456a5 Mon Sep 17 00:00:00 2001 From: Thomas Koenig Date: Tue, 19 Jul 2016 21:25:33 +0000 Subject: [PATCH] re PR fortran/71902 (Unneeded temporary on reallocatable character assignment) 2016-07-19 Thomas Koenig PR fortran/71902 * dependency.c (gfc_check_dependency): Use dep_ref. Handle case if identical is true and two array element references differ. (gfc_dep_resovler): Move most of the code to dep_ref. (dep_ref): New function. * frontend-passes.c (realloc_string_callback): Name temporary variable "realloc_string". 2016-07-19 Thomas Koenig PR fortran/71902 * gfortran.dg/dependency_47.f90: New test. From-SVN: r238497 --- gcc/fortran/ChangeLog | 10 +++ gcc/fortran/dependency.c | 79 +++++++++++++++++---- gcc/fortran/frontend-passes.c | 2 +- gcc/testsuite/ChangeLog | 5 ++ gcc/testsuite/gfortran.dg/dependency_47.f90 | 15 ++++ 5 files changed, 96 insertions(+), 15 deletions(-) create mode 100644 gcc/testsuite/gfortran.dg/dependency_47.f90 diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog index 04335d92726..2912fcb125e 100644 --- a/gcc/fortran/ChangeLog +++ b/gcc/fortran/ChangeLog @@ -1,3 +1,13 @@ +2016-07-19 Thomas Koenig + + PR fortran/71902 + * dependency.c (gfc_check_dependency): Use dep_ref. Handle case + if identical is true and two array element references differ. + (gfc_dep_resovler): Move most of the code to dep_ref. + (dep_ref): New function. + * frontend-passes.c (realloc_string_callback): Name temporary + variable "realloc_string". + 2016-07-17 Fritz Reese PR fortran/71523 diff --git a/gcc/fortran/dependency.c b/gcc/fortran/dependency.c index f117de03640..a873dbe933c 100644 --- a/gcc/fortran/dependency.c +++ b/gcc/fortran/dependency.c @@ -54,6 +54,8 @@ enum gfc_dependency static gfc_dependency check_section_vs_section (gfc_array_ref *, gfc_array_ref *, int); +static gfc_dependency dep_ref (gfc_ref *, gfc_ref *, gfc_reverse *); + /* Returns 1 if the expr is an integer constant value 1, 0 if it is not or def if the value could not be determined. */ @@ -1316,13 +1318,33 @@ gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical) return 0; } - if (identical) - return 1; - /* Identical and disjoint ranges return 0, overlapping ranges return 1. */ if (expr1->ref && expr2->ref) - return gfc_dep_resolver (expr1->ref, expr2->ref, NULL); + { + gfc_dependency dep; + dep = dep_ref (expr1->ref, expr2->ref, NULL); + switch (dep) + { + case GFC_DEP_EQUAL: + return identical; + + case GFC_DEP_FORWARD: + return 0; + + case GFC_DEP_BACKWARD: + return 1; + + case GFC_DEP_OVERLAP: + return 1; + + case GFC_DEP_NODEP: + return 0; + + default: + gcc_unreachable(); + } + } return 1; @@ -2052,10 +2074,38 @@ ref_same_as_full_array (gfc_ref *full_ref, gfc_ref *ref) 2 : array references are overlapping but reversal of one or more dimensions will clear the dependency. 1 : array references are overlapping. - 0 : array references are identical or not overlapping. */ + 0 : array references are identical or can be handled in a forward loop. */ int gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) +{ + enum gfc_dependency dep; + dep = dep_ref (lref, rref, reverse); + switch (dep) + { + case GFC_DEP_EQUAL: + return 0; + + case GFC_DEP_FORWARD: + return 0; + + case GFC_DEP_BACKWARD: + return 2; + + case GFC_DEP_OVERLAP: + return 1; + + case GFC_DEP_NODEP: + return 0; + + default: + gcc_unreachable(); + } +} + + +static gfc_dependency +dep_ref (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) { int n; int m; @@ -2079,21 +2129,22 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) /* The two ranges can't overlap if they are from different components. */ if (lref->u.c.component != rref->u.c.component) - return 0; + return GFC_DEP_NODEP; break; case REF_SUBSTRING: /* Substring overlaps are handled by the string assignment code if there is not an underlying dependency. */ - return (fin_dep == GFC_DEP_OVERLAP) ? 1 : 0; + + return fin_dep == GFC_DEP_ERROR ? GFC_DEP_NODEP : fin_dep; case REF_ARRAY: if (ref_same_as_full_array (lref, rref)) - return 0; + return GFC_DEP_EQUAL; if (ref_same_as_full_array (rref, lref)) - return 0; + return GFC_DEP_EQUAL; if (lref->u.ar.dimen != rref->u.ar.dimen) { @@ -2104,7 +2155,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) fin_dep = gfc_full_array_ref_p (lref, NULL) ? GFC_DEP_EQUAL : GFC_DEP_OVERLAP; else - return 1; + return GFC_DEP_OVERLAP; break; } @@ -2148,7 +2199,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) /* If any dimension doesn't overlap, we have no dependency. */ if (this_dep == GFC_DEP_NODEP) - return 0; + return GFC_DEP_NODEP; /* Now deal with the loop reversal logic: This only works on ranges and is activated by setting @@ -2215,7 +2266,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) /* Exactly matching and forward overlapping ranges don't cause a dependency. */ if (fin_dep < GFC_DEP_BACKWARD) - return 0; + return fin_dep == GFC_DEP_ERROR ? GFC_DEP_NODEP : fin_dep; /* Keep checking. We only have a dependency if subsequent references also overlap. */ @@ -2233,7 +2284,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) /* Assume the worst if we nest to different depths. */ if (lref || rref) - return 1; + return GFC_DEP_OVERLAP; - return fin_dep == GFC_DEP_OVERLAP; + return fin_dep; } diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c index 9ae3421da05..d4dee47ab75 100644 --- a/gcc/fortran/frontend-passes.c +++ b/gcc/fortran/frontend-passes.c @@ -185,7 +185,7 @@ realloc_string_callback (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED, current_code = c; inserted_block = NULL; changed_statement = NULL; - n = create_var (expr2, "trim"); + n = create_var (expr2, "realloc_string"); co->expr2 = n; return 0; } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ceae017ce8f..47ca5262864 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-07-19 Thomas Koenig + + PR fortran/71902 + * gfortran.dg/dependency_47.f90: New test. + 2016-07-19 Jakub Jelinek PR rtl-optimization/71916 diff --git a/gcc/testsuite/gfortran.dg/dependency_47.f90 b/gcc/testsuite/gfortran.dg/dependency_47.f90 new file mode 100644 index 00000000000..eebc910766d --- /dev/null +++ b/gcc/testsuite/gfortran.dg/dependency_47.f90 @@ -0,0 +1,15 @@ +! { dg-do compile } +! Make sure there is only one instance of a temporary variable here. +! { dg-options "-fdump-tree-original" } + +SUBROUTINE prtdata(ilen) + INTEGER :: ilen + character(len=ilen), allocatable :: cline(:) + allocate(cline(2)) + cline(1) = 'a' + cline(1)(2:3) = cline(1)(1:2) + cline(2) = cline(1) + print *,c +END SUBROUTINE prtdata +! { dg-final { scan-tree-dump-not "__var_2" "original" } } +! { dg-final { scan-tree-dump-times "__var_1" 3 "original" } }