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* [Bug fortran/25714] New: concat of strings create an extra temporary variable @ 2006-01-08 3:12 pinskia at gcc dot gnu dot org 2006-01-08 3:12 ` [Bug fortran/25714] " pinskia at gcc dot gnu dot org ` (3 more replies) 0 siblings, 4 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2006-01-08 3:12 UTC (permalink / raw) To: gcc-bugs Take: character(2) :: c character(1) :: a character(1) :: b c = a//b end ---- We get: _gfortran_concat_string (2, str.1, 1, &a, 1, &b); _gfortran_copy_string (2, &c, 2, str.1); We should be able to get: _gfortran_concat_string (2, &c, 1, &a, 1, &b); Instead and get rid of the tempory variable of str.1. -- Summary: concat of strings create an extra temporary variable Product: gcc Version: 4.2.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pinskia at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug fortran/25714] concat of strings create an extra temporary variable 2006-01-08 3:12 [Bug fortran/25714] New: concat of strings create an extra temporary variable pinskia at gcc dot gnu dot org @ 2006-01-08 3:12 ` pinskia at gcc dot gnu dot org 2006-01-29 21:06 ` pinskia at gcc dot gnu dot org ` (2 subsequent siblings) 3 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2006-01-08 3:12 UTC (permalink / raw) To: gcc-bugs -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Severity|normal |enhancement http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug fortran/25714] concat of strings create an extra temporary variable 2006-01-08 3:12 [Bug fortran/25714] New: concat of strings create an extra temporary variable pinskia at gcc dot gnu dot org 2006-01-08 3:12 ` [Bug fortran/25714] " pinskia at gcc dot gnu dot org @ 2006-01-29 21:06 ` pinskia at gcc dot gnu dot org 2007-02-07 0:21 ` fxcoudert at gcc dot gnu dot org 2007-03-03 12:14 ` fxcoudert at gcc dot gnu dot org 3 siblings, 0 replies; 9+ messages in thread From: pinskia at gcc dot gnu dot org @ 2006-01-29 21:06 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from pinskia at gcc dot gnu dot org 2006-01-29 21:06 ------- Confirmed. -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|0000-00-00 00:00:00 |2006-01-29 21:06:06 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug fortran/25714] concat of strings create an extra temporary variable 2006-01-08 3:12 [Bug fortran/25714] New: concat of strings create an extra temporary variable pinskia at gcc dot gnu dot org 2006-01-08 3:12 ` [Bug fortran/25714] " pinskia at gcc dot gnu dot org 2006-01-29 21:06 ` pinskia at gcc dot gnu dot org @ 2007-02-07 0:21 ` fxcoudert at gcc dot gnu dot org 2007-03-03 12:14 ` fxcoudert at gcc dot gnu dot org 3 siblings, 0 replies; 9+ messages in thread From: fxcoudert at gcc dot gnu dot org @ 2007-02-07 0:21 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from fxcoudert at gcc dot gnu dot org 2007-02-07 00:21 ------- Here's another patch for concat, to have the front-end generate the code itself instead of calling a library function. It still generates the extra temporary, but can optimize other things. Index: trans-expr.c =================================================================== --- trans-expr.c (revision 121506) +++ trans-expr.c (working copy) @@ -934,6 +934,36 @@ } +/* Helper for gfc_trans_array_copy, gfc_trans_array_constructor_copy + and gfc_conv_concat_op that constructs the call to __builtin_memcpy. */ + +static tree +gfc_build_memcpy_call (tree dst, tree src, tree len) +{ + tree tmp, args; + + /* Convert arguments to the correct types. */ + if (!POINTER_TYPE_P (TREE_TYPE (dst))) + dst = gfc_build_addr_expr (pvoid_type_node, dst); + else + dst = fold_convert (pvoid_type_node, dst); + + if (!POINTER_TYPE_P (TREE_TYPE (src))) + src = gfc_build_addr_expr (pvoid_type_node, src); + else + src = fold_convert (pvoid_type_node, src); + + len = fold_convert (size_type_node, len); + + /* Construct call to __builtin_memcpy. */ + args = build_tree_list (NULL_TREE, len); + args = tree_cons (NULL_TREE, src, args); + args = tree_cons (NULL_TREE, dst, args); + tmp = build_function_call_expr (built_in_decls[BUILT_IN_MEMCPY], args); + return fold_convert (void_type_node, tmp); +} + + /* Handle a string concatenation operation. A temporary will be allocated to hold the result. */ @@ -942,11 +972,15 @@ { gfc_se lse; gfc_se rse; - tree len; + tree destlen; tree type; - tree var; + tree dest; tree args; tree tmp; + tree d; + tree dlen; + tree cond1, cond2, action1, action2, expr_block1, expr_block2; + stmtblock_t block1, block2; gcc_assert (expr->value.op.op1->ts.type == BT_CHARACTER && expr->value.op.op2->ts.type == BT_CHARACTER); @@ -962,34 +996,92 @@ gfc_add_block_to_block (&se->pre, &rse.pre); type = gfc_get_character_type (expr->ts.kind, expr->ts.cl); - len = TYPE_MAX_VALUE (TYPE_DOMAIN (type)); - if (len == NULL_TREE) - { - len = fold_build2 (PLUS_EXPR, TREE_TYPE (lse.string_length), - lse.string_length, rse.string_length); - } + destlen = TYPE_MAX_VALUE (TYPE_DOMAIN (type)); + if (destlen == NULL_TREE) + destlen = fold_build2 (PLUS_EXPR, TREE_TYPE (lse.string_length), + lse.string_length, rse.string_length); type = build_pointer_type (type); - var = gfc_conv_string_tmp (se, type, len); + dest = gfc_conv_string_tmp (se, type, destlen); - /* Do the actual concatenation. */ - args = NULL_TREE; - args = gfc_chainon_list (args, len); - args = gfc_chainon_list (args, var); - args = gfc_chainon_list (args, lse.string_length); - args = gfc_chainon_list (args, lse.expr); - args = gfc_chainon_list (args, rse.string_length); - args = gfc_chainon_list (args, rse.expr); - tmp = build_function_call_expr (gfor_fndecl_concat_string, args); + /* Do the actual concatenation. The original code in libgfortran was: + + void + concat_string (GFC_INTEGER_4 destlen, char * dest, + GFC_INTEGER_4 len1, const char * s1, + GFC_INTEGER_4 len2, const char * s2) + { + if (len1 >= destlen) + { + memcpy (dest, s1, destlen); + return; + } + memcpy (dest, s1, len1); + dest += len1; + destlen -= len1; + + if (len2 >= destlen) + { + memcpy (dest, s2, destlen); + } + else + { + memcpy (dest, s2, len2); + memset (&dest[len2], ' ', destlen - len2); + } + } + + And that's exactly what we do here. + */ + + cond1 = fold_build2 (GE_EXPR, boolean_type_node, lse.string_length, destlen + action1 = gfc_build_memcpy_call (dest, lse.expr, destlen); + + gfc_start_block (&block1); + tmp = gfc_build_memcpy_call (dest, lse.expr, lse.string_length); + gfc_add_expr_to_block (&block1, tmp); + dlen = gfc_create_var (TREE_TYPE (destlen), "dlen"); + d = gfc_create_var (pchar_type_node, "d"); + tmp = fold_build2 (MINUS_EXPR, TREE_TYPE (dlen), destlen, lse.string_length + gfc_add_modify_expr (&block1, dlen, tmp); + tmp = fold_build2 (PLUS_EXPR, pchar_type_node, dest, + fold_convert (pchar_type_node, lse.string_length)); + gfc_add_modify_expr (&block1, d, tmp); + + gfc_init_block (&block2); + tmp = gfc_build_memcpy_call (d, rse.expr, rse.string_length); + gfc_add_expr_to_block (&block2, tmp); + + /* Call to memset. */ + args = fold_build2 (PLUS_EXPR, pchar_type_node, d, + fold_convert (pchar_type_node, rse.string_length)); + args = gfc_chainon_list (NULL_TREE, args); + args = gfc_chainon_list (args, build_int_cst + (gfc_get_int_type (gfc_c_int_kind), + lang_hooks.to_target_charset (' '))); + args = gfc_chainon_list (args, fold_build2 (MINUS_EXPR, TREE_TYPE(dlen), + dlen, rse.string_length)); + tmp = build_function_call_expr (built_in_decls[BUILT_IN_MEMSET], args); + + gfc_add_expr_to_block (&block2, tmp); + expr_block2 = gfc_finish_block (&block2); + + cond2 = fold_build2 (GE_EXPR, boolean_type_node, rse.string_length, dlen); + action2 = gfc_build_memcpy_call (d, rse.expr, dlen); + tmp = fold_build3 (COND_EXPR, void_type_node, cond2, action2, expr_block2); + gfc_add_expr_to_block (&block1, tmp); + expr_block1 = gfc_finish_block (&block1); + + tmp = fold_build3 (COND_EXPR, void_type_node, cond1, action1, expr_block1); gfc_add_expr_to_block (&se->pre, tmp); /* Add the cleanup for the operands. */ gfc_add_block_to_block (&se->pre, &rse.post); gfc_add_block_to_block (&se->pre, &lse.post); - se->expr = var; - se->string_length = len; + se->expr = dest; + se->string_length = destlen; } /* Translates an op expression. Common (binary) cases are handled by this @@ -3622,36 +3713,6 @@ } -/* Helper for gfc_trans_array_copy and gfc_trans_array_constructor_copy - that constructs the call to __builtin_memcpy. */ - -static tree -gfc_build_memcpy_call (tree dst, tree src, tree len) -{ - tree tmp, args; - - /* Convert arguments to the correct types. */ - if (!POINTER_TYPE_P (TREE_TYPE (dst))) - dst = gfc_build_addr_expr (pvoid_type_node, dst); - else - dst = fold_convert (pvoid_type_node, dst); - - if (!POINTER_TYPE_P (TREE_TYPE (src))) - src = gfc_build_addr_expr (pvoid_type_node, src); - else - src = fold_convert (pvoid_type_node, src); - - len = fold_convert (size_type_node, len); - - /* Construct call to __builtin_memcpy. */ - args = build_tree_list (NULL_TREE, len); - args = tree_cons (NULL_TREE, src, args); - args = tree_cons (NULL_TREE, dst, args); - tmp = build_function_call_expr (built_in_decls[BUILT_IN_MEMCPY], args); - return fold_convert (void_type_node, tmp); -} - - /* Try to efficiently translate dst(:) = src(:). Return NULL if this can't be done. EXPR1 is the destination/lhs and EXPR2 is the source/rhs, both are gfc_full_array_ref_p which have been checked for -- fxcoudert at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |fxcoudert at gcc dot gnu dot | |org Last reconfirmed|2006-08-21 06:16:16 |2007-02-07 00:21:21 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug fortran/25714] concat of strings create an extra temporary variable 2006-01-08 3:12 [Bug fortran/25714] New: concat of strings create an extra temporary variable pinskia at gcc dot gnu dot org ` (2 preceding siblings ...) 2007-02-07 0:21 ` fxcoudert at gcc dot gnu dot org @ 2007-03-03 12:14 ` fxcoudert at gcc dot gnu dot org 3 siblings, 0 replies; 9+ messages in thread From: fxcoudert at gcc dot gnu dot org @ 2007-03-03 12:14 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from fxcoudert at gcc dot gnu dot org 2007-03-03 12:14 ------- Created an attachment (id=13136) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13136&action=view) Updated version of the patch in comment 2 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 ^ permalink raw reply [flat|nested] 9+ messages in thread
[parent not found: <bug-25714-4@http.gcc.gnu.org/bugzilla/>]
* [Bug fortran/25714] concat of strings create an extra temporary variable [not found] <bug-25714-4@http.gcc.gnu.org/bugzilla/> @ 2010-12-26 0:42 ` tkoenig at gcc dot gnu.org 2014-12-07 10:24 ` dominiq at lps dot ens.fr ` (2 subsequent siblings) 3 siblings, 0 replies; 9+ messages in thread From: tkoenig at gcc dot gnu.org @ 2010-12-26 0:42 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 Thomas Koenig <tkoenig at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED AssignedTo|unassigned at gcc dot |tkoenig at gcc dot gnu.org |gnu.org | --- Comment #4 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2010-12-26 00:42:35 UTC --- The test case from comment#1 could be done as c(1:1) = a c(2:2) = b in the front end optimization pass. I'll give it a shot. ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug fortran/25714] concat of strings create an extra temporary variable [not found] <bug-25714-4@http.gcc.gnu.org/bugzilla/> 2010-12-26 0:42 ` tkoenig at gcc dot gnu.org @ 2014-12-07 10:24 ` dominiq at lps dot ens.fr 2015-05-16 6:07 ` tkoenig at gcc dot gnu.org 2021-06-29 2:52 ` tobi at gcc dot gnu.org 3 siblings, 0 replies; 9+ messages in thread From: dominiq at lps dot ens.fr @ 2014-12-07 10:24 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 Dominique d'Humieres <dominiq at lps dot ens.fr> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |fxcoudert at gcc dot gnu.org --- Comment #5 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- Still present at r218462. ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug fortran/25714] concat of strings create an extra temporary variable [not found] <bug-25714-4@http.gcc.gnu.org/bugzilla/> 2010-12-26 0:42 ` tkoenig at gcc dot gnu.org 2014-12-07 10:24 ` dominiq at lps dot ens.fr @ 2015-05-16 6:07 ` tkoenig at gcc dot gnu.org 2021-06-29 2:52 ` tobi at gcc dot gnu.org 3 siblings, 0 replies; 9+ messages in thread From: tkoenig at gcc dot gnu.org @ 2015-05-16 6:07 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 Thomas Koenig <tkoenig at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |NEW Assignee|tkoenig at gcc dot gnu.org |unassigned at gcc dot gnu.org --- Comment #6 from Thomas Koenig <tkoenig at gcc dot gnu.org> --- Working on other stuff, unassigning for now. ^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug fortran/25714] concat of strings create an extra temporary variable [not found] <bug-25714-4@http.gcc.gnu.org/bugzilla/> ` (2 preceding siblings ...) 2015-05-16 6:07 ` tkoenig at gcc dot gnu.org @ 2021-06-29 2:52 ` tobi at gcc dot gnu.org 3 siblings, 0 replies; 9+ messages in thread From: tobi at gcc dot gnu.org @ 2021-06-29 2:52 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25714 --- Comment #8 from Tobias Schlüter <tobi at gcc dot gnu.org> --- No more temporary FAICT https://godbolt.org/z/o8fYE1nej If written as a proper function: function c(a, b) character(2) :: c character(1) :: a character(1) :: b c = a//b end we get: c_: push rbx mov r9, rcx mov rbx, rdi mov rcx, rdx mov r8d, 1 mov edx, 1 mov edi, 2 sub rsp, 16 lea rsi, [rsp+14] call _gfortran_concat_string movzx eax, WORD PTR [rsp+14] mov WORD PTR [rbx], ax add rsp, 16 pop rbx ret ... and likewise for the original testcase. ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2021-06-29 2:52 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2006-01-08 3:12 [Bug fortran/25714] New: concat of strings create an extra temporary variable pinskia at gcc dot gnu dot org 2006-01-08 3:12 ` [Bug fortran/25714] " pinskia at gcc dot gnu dot org 2006-01-29 21:06 ` pinskia at gcc dot gnu dot org 2007-02-07 0:21 ` fxcoudert at gcc dot gnu dot org 2007-03-03 12:14 ` fxcoudert at gcc dot gnu dot org [not found] <bug-25714-4@http.gcc.gnu.org/bugzilla/> 2010-12-26 0:42 ` tkoenig at gcc dot gnu.org 2014-12-07 10:24 ` dominiq at lps dot ens.fr 2015-05-16 6:07 ` tkoenig at gcc dot gnu.org 2021-06-29 2:52 ` tobi at gcc dot gnu.org
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