From patchwork Mon Mar 25 15:43:22 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: *ping* [patch, fortran, 4.9] Dependency and string length calculation improvements From: Thomas Koenig X-Patchwork-Id: 230750 Message-Id: <5150709A.6030201@netcologne.de> To: "fortran@gcc.gnu.org" , gcc-patches Date: Mon, 25 Mar 2013 16:43:22 +0100 *ping* Slightly updated patch below, with a better test case as suggested by Dominique. OK for trunk? 2013-03-16 Thomas Koenig PR fortran/45159 * gfortran.h (gfc_dep_difference): Add prototype. * dependency.c (discard_nops): New function. (gfc_dep_difference): New function. (check_section_vs_section): Use gfc_dep_difference to calculate the difference of starting indices. * trans-expr.c (gfc_conv_substring): Use gfc_dep_difference to calculate the length of substrings where possible. 2013-03-16 Thomas Koenig PR fortran/45159 * gfortran.dg/string_length_2.f90: New test. * gfortran.dg/dependency_41.f90: New test. Index: gfortran.h =================================================================== --- gfortran.h (Revision 196574) +++ gfortran.h (Arbeitskopie) @@ -2959,6 +2959,7 @@ gfc_namespace* gfc_build_block_ns (gfc_namespace * /* dependency.c */ int gfc_dep_compare_functions (gfc_expr *, gfc_expr *, bool); int gfc_dep_compare_expr (gfc_expr *, gfc_expr *); +bool gfc_dep_difference (gfc_expr *, gfc_expr *, mpz_t *); /* check.c */ gfc_try gfc_check_same_strlen (const gfc_expr*, const gfc_expr*, const char*); Index: dependency.c =================================================================== --- dependency.c (Revision 196574) +++ dependency.c (Arbeitskopie) @@ -500,7 +500,270 @@ gfc_dep_compare_expr (gfc_expr *e1, gfc_expr *e2) } } +/* Helper function to look through parens and unary plus. */ +static gfc_expr* +discard_nops (gfc_expr *e) +{ + + while (e && e->expr_type == EXPR_OP + && (e->value.op.op == INTRINSIC_UPLUS + || e->value.op.op == INTRINSIC_PARENTHESES)) + e = e->value.op.op1; + + return e; +} +/* Return the difference between two expressions. Integer expressions of + the form + + X + constant, X - constant and constant + X + + are handled. Return true on success, false on failure. result is assumed + to be uninitialized on entry, and will be initialized on success. +*/ + +bool +gfc_dep_difference (gfc_expr *e1, gfc_expr *e2, mpz_t *result) +{ + gfc_expr *e1_op1, *e1_op2, *e2_op1, *e2_op2; + + if (e1 == NULL || e2 == NULL) + return false; + + if (e1->ts.type != BT_INTEGER || e2->ts.type != BT_INTEGER) + return false; + + e1 = discard_nops (e1); + e2 = discard_nops (e2); + + /* Inizialize tentatively, clear if we don't return anything. */ + mpz_init (*result); + + /* Case 1: c1 - c2 = c1 - c2, trivially. */ + + if (e1->expr_type == EXPR_CONSTANT && e2->expr_type == EXPR_CONSTANT) + { + mpz_sub (*result, e1->value.integer, e2->value.integer); + return true; + } + + if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_PLUS) + { + e1_op1 = discard_nops (e1->value.op.op1); + e1_op2 = discard_nops (e1->value.op.op2); + + /* Case 2: (X + c1) - X = c1. */ + if (e1_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op1, e2) == 0) + { + mpz_set (*result, e1_op2->value.integer); + return true; + } + + /* Case 3: (c1 + X) - X = c1. */ + if (e1_op1->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op2, e2) == 0) + { + mpz_set (*result, e1_op1->value.integer); + return true; + } + + if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) + { + e2_op1 = discard_nops (e2->value.op.op1); + e2_op2 = discard_nops (e2->value.op.op2); + + if (e1_op2->expr_type == EXPR_CONSTANT) + { + /* Case 4: X + c1 - (X + c2) = c1 - c2. */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) + { + mpz_sub (*result, e1_op2->value.integer, + e2_op2->value.integer); + return true; + } + /* Case 5: X + c1 - (c2 + X) = c1 - c2. */ + if (e2_op1->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op1, e2_op2) == 0) + { + mpz_sub (*result, e1_op2->value.integer, + e2_op1->value.integer); + return true; + } + } + else if (e1_op1->expr_type == EXPR_CONSTANT) + { + /* Case 6: c1 + X - (X + c2) = c1 - c2. */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op2, e2_op1) == 0) + { + mpz_sub (*result, e1_op1->value.integer, + e2_op2->value.integer); + return true; + } + /* Case 7: c1 + X - (c2 + X) = c1 - c2. */ + if (e2_op1->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op2, e2_op2) == 0) + { + mpz_sub (*result, e1_op1->value.integer, + e2_op1->value.integer); + return true; + } + } + } + + if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) + { + e2_op1 = discard_nops (e2->value.op.op1); + e2_op2 = discard_nops (e2->value.op.op2); + + if (e1_op2->expr_type == EXPR_CONSTANT) + { + /* Case 8: X + c1 - (X - c2) = c1 + c2. */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) + { + mpz_add (*result, e1_op2->value.integer, + e2_op2->value.integer); + return true; + } + } + if (e1_op1->expr_type == EXPR_CONSTANT) + { + /* Case 9: c1 + X - (X - c2) = c1 + c2. */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op2, e2_op1) == 0) + { + mpz_add (*result, e1_op1->value.integer, + e2_op2->value.integer); + return true; + } + } + } + } + + if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_MINUS) + { + e1_op1 = discard_nops (e1->value.op.op1); + e1_op2 = discard_nops (e1->value.op.op2); + + if (e1_op2->expr_type == EXPR_CONSTANT) + { + /* Case 10: (X - c1) - X = -c1 */ + + if (gfc_dep_compare_expr (e1_op1, e2) == 0) + { + mpz_neg (*result, e1_op2->value.integer); + return true; + } + + if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) + { + e2_op1 = discard_nops (e2->value.op.op1); + e2_op2 = discard_nops (e2->value.op.op2); + + /* Case 11: (X - c1) - (X + c2) = -( c1 + c2). */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) + { + mpz_add (*result, e1_op2->value.integer, + e2_op2->value.integer); + mpz_neg (*result, *result); + return true; + } + + /* Case 12: X - c1 - (c2 + X) = - (c1 + c2). */ + if (e2_op1->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op1, e2_op2) == 0) + { + mpz_add (*result, e1_op2->value.integer, + e2_op1->value.integer); + mpz_neg (*result, *result); + return true; + } + } + + if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) + { + e2_op1 = discard_nops (e2->value.op.op1); + e2_op2 = discard_nops (e2->value.op.op2); + + /* Case 13: (X - c1) - (X - c2) = c2 - c1. */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) + { + mpz_sub (*result, e2_op2->value.integer, + e1_op2->value.integer); + return true; + } + } + } + if (e1_op1->expr_type == EXPR_CONSTANT) + { + if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) + { + e2_op1 = discard_nops (e2->value.op.op1); + e2_op2 = discard_nops (e2->value.op.op2); + + /* Case 14: (c1 - X) - (c2 - X) == c1 - c2. */ + if (gfc_dep_compare_expr (e1_op2, e2_op2) == 0) + { + mpz_sub (*result, e1_op1->value.integer, + e2_op1->value.integer); + return true; + } + } + + } + } + + if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) + { + e2_op1 = discard_nops (e2->value.op.op1); + e2_op2 = discard_nops (e2->value.op.op2); + + /* Case 15: X - (X + c2) = -c2. */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1, e2_op1) == 0) + { + mpz_neg (*result, e2_op2->value.integer); + return true; + } + /* Case 16: X - (c2 + X) = -c2. */ + if (e2_op1->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1, e2_op2) == 0) + { + mpz_neg (*result, e2_op1->value.integer); + return true; + } + } + + if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) + { + e2_op1 = discard_nops (e2->value.op.op1); + e2_op2 = discard_nops (e2->value.op.op2); + + /* Case 17: X - (X - c2) = c2. */ + if (e2_op2->expr_type == EXPR_CONSTANT + && gfc_dep_compare_expr (e1, e2_op1) == 0) + { + mpz_set (*result, e2_op2->value.integer); + return true; + } + } + + if (gfc_dep_compare_expr(e1, e2) == 0) + { + /* Case 18: X - X = 0. */ + mpz_set_si (*result, 0); + return true; + } + + mpz_clear (*result); + return false; +} + /* Returns 1 if the two ranges are the same and 0 if they are not (or if the results are indeterminate). 'n' is the dimension to compare. */ @@ -1140,6 +1403,7 @@ check_section_vs_section (gfc_array_ref *l_ar, gfc int r_dir; int stride_comparison; int start_comparison; + mpz_t tmp; /* If they are the same range, return without more ado. */ if (is_same_range (l_ar, r_ar, n)) @@ -1282,23 +1546,20 @@ check_section_vs_section (gfc_array_ref *l_ar, gfc #define IS_CONSTANT_INTEGER(a) ((a) && ((a)->expr_type == EXPR_CONSTANT) \ && (a)->ts.type == BT_INTEGER) - if (IS_CONSTANT_INTEGER(l_start) && IS_CONSTANT_INTEGER(r_start) - && IS_CONSTANT_INTEGER(l_stride) && IS_CONSTANT_INTEGER(r_stride)) + if (IS_CONSTANT_INTEGER(l_stride) && IS_CONSTANT_INTEGER(r_stride) + && gfc_dep_difference (l_start, r_start, &tmp)) { - mpz_t gcd, tmp; + mpz_t gcd; int result; mpz_init (gcd); - mpz_init (tmp); - mpz_gcd (gcd, l_stride->value.integer, r_stride->value.integer); - mpz_sub (tmp, l_start->value.integer, r_start->value.integer); mpz_fdiv_r (tmp, tmp, gcd); result = mpz_cmp_si (tmp, 0L); mpz_clear (gcd); - mpz_clear (tmp); + mpz_clear (tmp); /* gfc_dep_difference returned true, so tmp was initialized. */ if (result != 0) return GFC_DEP_NODEP; Index: trans-expr.c =================================================================== --- trans-expr.c (Revision 196574) +++ trans-expr.c (Arbeitskopie) @@ -1437,6 +1437,7 @@ gfc_conv_substring (gfc_se * se, gfc_ref * ref, in gfc_se start; gfc_se end; char *msg; + mpz_t length; type = gfc_get_character_type (kind, ref->u.ss.length); type = build_pointer_type (type); @@ -1520,10 +1521,19 @@ gfc_conv_substring (gfc_se * se, gfc_ref * ref, in free (msg); } - /* If the start and end expressions are equal, the length is one. */ + /* Try to calculate the length from the start and end expressions. */ if (ref->u.ss.end - && gfc_dep_compare_expr (ref->u.ss.start, ref->u.ss.end) == 0) - tmp = build_int_cst (gfc_charlen_type_node, 1); + && gfc_dep_difference (ref->u.ss.end, ref->u.ss.start, &length)) + { + int i_len; + + i_len = mpz_get_si (length) + 1; + if (i_len < 0) + i_len = 0; + + tmp = build_int_cst (gfc_charlen_type_node, i_len); + mpz_clear (length); /* Was initialized by gfc_dep_difference. */ + } else { tmp = fold_build2_loc (input_location, MINUS_EXPR, gfc_charlen_type_node,