On Thu, 9 Jul 2015, Bernhard Reutner-Fischer wrote: > gcc/ChangeLog > > 2015-07-09 Bernhard Reutner-Fischer <al...@gcc.gnu.org> > > * builtins.c (fold_builtin_tolower, fold_builtin_toupper): New > static functions. > (fold_builtin_1): Handle BUILT_IN_TOLOWER, BUILT_IN_TOUPPER.
As I read it you fold tolower (X) to (X) >= target_char_set ('A') && (X) <= target_char_set ('Z') ? (X) - target_char_set ('A') + target_char_set ('a'); I don't think this can be correct for all locales which need not have a lower-case character for all upper-case ones nor do all letters having one need to be in the range of 'A' to 'Z'. Joseph will surely correct me if I am wrong. What works would eventually be constant folding. Richard. > Signed-off-by: Bernhard Reutner-Fischer <rep.dot....@gmail.com> > --- > gcc/builtins.c | 99 > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 99 insertions(+) > > Using the three testcases attached to PR66741 where the -1.c one is using > builtins > $ for i in 0 1 2;do gcc -o tolower_strcpy-$i tolower_strcpy-$i.c -Ofast -W > -Wall -Wextra -pedantic -DMAIN -msse4.2;done > > pristine (trunk@225368): > # tolower_strcpy-0 > > real 0m6.068s > user 0m3.204s > sys 0m2.840s > # tolower_strcpy-1 > > real 0m8.097s > user 0m5.548s > sys 0m2.528s > # tolower_strcpy-2 > > real 0m3.568s > user 0m0.804s > sys 0m2.748s > > trunk@225368 + fold tolower/toupper below > > # tolower_strcpy-0 > > real 0m6.055s > user 0m3.212s > sys 0m2.832s > # tolower_strcpy-1 > > real 0m5.383s > user 0m2.464s > sys 0m2.900s > # tolower_strcpy-2 > > real 0m3.605s > user 0m0.668s > sys 0m2.924s > > The tolower loop now ends up as > .L5: > movsbl (%rbx), %edx > leal 32(%rdx), %ecx > movl %edx, %eax > subl $65, %edx > cmpl $25, %edx > cmovbe %ecx, %eax > addq $1, %rbx > movb %al, -1(%rbx) > cmpq %rsi, %rbx > jne .L5 > > instead of the former call > > .L5: > movsbl (%rbx), %edi > addq $1, %rbx > call tolower > movb %al, -1(%rbx) > cmpq %rbp, %rbx > jne .L5 > > Would something like attached be ok for trunk after proper testing? > Advise on the questions inline WRT caching lang_hooks intermediate > results? > Hints on further steps towards fixing the PR? > > I think the next step would be to try to teach graphite to fuse the two > loops in tolower_strcpy-0.c. Need to look at graphite.. > Then see how to classify builtins that could be expanded early and what > breaks if doing so. This sounds like a potential disaster, fun. > Next, see why the vectorizer (or something else) does not pave the way > to use SSE instruction as the tolower_strcpy-2.c does. > > thanks, > > diff --git a/gcc/builtins.c b/gcc/builtins.c > index 5f53342..421c908 100644 > --- a/gcc/builtins.c > +++ b/gcc/builtins.c > @@ -204,6 +204,9 @@ static tree fold_builtin_strrchr (location_t, tree, tree, > tree); > static tree fold_builtin_strspn (location_t, tree, tree); > static tree fold_builtin_strcspn (location_t, tree, tree); > > +static tree fold_builtin_tolower (location_t, tree); > +static tree fold_builtin_toupper (location_t, tree); > + > static rtx expand_builtin_object_size (tree); > static rtx expand_builtin_memory_chk (tree, rtx, machine_mode, > enum built_in_function); > @@ -10285,6 +10288,12 @@ fold_builtin_1 (location_t loc, tree fndecl, tree > arg0) > case BUILT_IN_ISDIGIT: > return fold_builtin_isdigit (loc, arg0); > > + case BUILT_IN_TOLOWER: > + return fold_builtin_tolower (loc, arg0); > + > + case BUILT_IN_TOUPPER: > + return fold_builtin_toupper (loc, arg0); > + > CASE_FLT_FN (BUILT_IN_FINITE): > case BUILT_IN_FINITED32: > case BUILT_IN_FINITED64: > @@ -11208,6 +11217,96 @@ fold_builtin_strcspn (location_t loc, tree s1, tree > s2) > } > } > > + > +/* Simplify a call to the tolower builtin. ARG is the argument to the call. > + > + Return NULL_TREE if no simplification was possible, otherwise return the > + simplified form of the call as a tree. */ > + > +static tree > +fold_builtin_tolower (location_t loc, tree arg) > +{ > + if (!validate_arg (arg, INTEGER_TYPE)) > + return NULL_TREE; > + > + /* Transform tolower(c) -> (unsigned)(c) | 0x20. > + > + More specifically: > + unsigned tem = arg - 'A'; > + if (tem <= ('Z' - 'A')) > + arg += 'a' - 'A'; > + return arg; > + */ > + unsigned HOST_WIDE_INT target_A = lang_hooks.to_target_charset ('A'); > + unsigned HOST_WIDE_INT target_Z = lang_hooks.to_target_charset ('Z'); > + unsigned HOST_WIDE_INT target_a = lang_hooks.to_target_charset ('a'); > + if (target_A == 0 > + || target_Z == 0 > + || target_a == 0) > + return NULL_TREE; > + > + arg = fold_convert_loc (loc, unsigned_type_node, arg); > + tree tem = fold_build2 (MINUS_EXPR, unsigned_type_node, arg, > + build_int_cst (unsigned_type_node, target_A)); > + /* ??? x19 and x20 would better live in static storage; Think: > + * static struct static_fold_tolower {uHWI x19, x20; unsigned probe_done}; > + */ > + unsigned HOST_WIDE_INT x19 = target_Z - target_A; > + unsigned HOST_WIDE_INT x20 = target_a - target_A; > + tem = fold_build2_loc (loc, LE_EXPR, integer_type_node, tem, > + build_int_cst (unsigned_type_node, x19)); > + tem = fold_build3_loc (loc, COND_EXPR, unsigned_type_node, tem, > + fold_build2 (PLUS_EXPR, unsigned_type_node, arg, > + build_int_cst (unsigned_type_node, x20)), > + arg); > + return fold_convert_loc (loc, integer_type_node, tem); > +} > + > +/* Simplify a call to the toupper builtin. ARG is the argument to the call. > + > + Return NULL_TREE if no simplification was possible, otherwise return the > + simplified form of the call as a tree. */ > + > +static tree > +fold_builtin_toupper (location_t loc, tree arg) > +{ > + if (!validate_arg (arg, INTEGER_TYPE)) > + return NULL_TREE; > + > + /* Transform toupper(c) -> (unsigned)(c) ^ 0x20. > + > + More specifically: > + unsigned tem = arg - 'a'; > + if (tem <= ('z' - 'a')) > + arg -= 'a' - 'A'; > + return arg; > + */ > + unsigned HOST_WIDE_INT target_A = lang_hooks.to_target_charset ('A'); > + unsigned HOST_WIDE_INT target_z = lang_hooks.to_target_charset ('z'); > + unsigned HOST_WIDE_INT target_a = lang_hooks.to_target_charset ('a'); > + if (target_A == 0 > + || target_z == 0 > + || target_a == 0) > + return NULL_TREE; > + > + arg = fold_convert_loc (loc, unsigned_type_node, arg); > + tree tem = fold_build2 (MINUS_EXPR, unsigned_type_node, arg, > + build_int_cst (unsigned_type_node, target_a)); > + /* ??? x19 and x20 would better live in static storage; Think: > + * static struct static_fold_tolower {uHWI x19, x20; unsigned probe_done}; > + */ > + unsigned HOST_WIDE_INT x19 = target_z - target_a; > + unsigned HOST_WIDE_INT x20 = target_a - target_A; > + tem = fold_build2_loc (loc, LE_EXPR, integer_type_node, tem, > + build_int_cst (unsigned_type_node, x19)); > + tem = fold_build3_loc (loc, COND_EXPR, unsigned_type_node, tem, > + fold_build2 (MINUS_EXPR, unsigned_type_node, arg, > + build_int_cst (unsigned_type_node, x20)), > + arg); > + return fold_convert_loc (loc, integer_type_node, tem); > +} > + > + > /* Fold the next_arg or va_start call EXP. Returns true if there was an error > produced. False otherwise. This is done so that we don't output the > error > or warning twice or three times. */ > -- Richard Biener <rguent...@suse.de> SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nuernberg)