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Re: [Gfortran, Patch] PR12456 - Optimize single character.
- From: Feng Wang <wf_cs at yahoo dot com>
- To: Andrew Pinski <pinskia at physics dot uc dot edu>, Paul Brook <paul at codesourcery dot com>
- Cc: fortran at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Date: Sat, 7 Jan 2006 19:02:51 +0800 (CST)
- Subject: Re: [Gfortran, Patch] PR12456 - Optimize single character.
This is the revised path. Bootstrap and regtested on i686-pc-linux-gnu.
OK for trunk and gcc 4.1?
fortran ChangeLog entry:
2006-01-07 Feng Wang <fengwang@nudt.edu.cn>
PR fortran/12456
* trans-expr.c (gfc_to_single_character): New function that converts
string to single character if its length is 1.
(gfc_build_compare_string):New function that compare string and handle
single character specially.
(gfc_conv_expr_op): Use gfc_build_compare_string.
(gfc_trans_string_copy): Use gfc_to_single_character.
* trans-intrinsic.c (gfc_conv_intrinsic_strcmp): Use
gfc_build_compare_string.
* trans.h (gfc_build_compare_string): Add prototype.
testsuite ChangeLog entry:
2006-01-07 Feng Wang <fengwang@nudt.edu.cn>
PR fortran/12456
* gfortran.dg/pr12456.f90: New test.
--- Feng Wang <wf_cs@yahoo.com> wrote:
> --- Andrew Pinski <pinskia@physics.uc.edu> wrote:
> >
> > On Jan 3, 2006, at 11:40 PM, Feng Wang wrote:
> >
Best Regards,
Feng Wang
--
Creative Compiler Research Group,
National University of Defense Technology, China.
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雅虎1G免费邮箱百分百防垃圾信
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! { dg-do run }
! { dg-options "-fdump-tree-original" }
! PR12456 - Optimize string(k:k) as single character.
Program pr12456
character a
character b
character (len=5) :: c
integer i
b = 'a'
a = b
if (a .ne. 'a') call abort()
if (a .ne. b) call abort()
c (3:3) = 'a'
if (c (3:3) .ne. b) call abort ()
if (c (3:3) .ne. 'a') call abort ()
if (LGT (a, c (3:3))) call abort ()
if (LGT (a, 'a')) call abort ()
i = 3
c (i:i) = 'a'
if (c (i:i) .ne. b) call abort ()
if (c (i:i) .ne. 'a') call abort ()
if (LGT (a, c (i:i))) call abort ()
if (a .gt. char (255)) call abort ()
end
! There should not be _gfortran_compare_string and _gfortran_copy_string in
! the dumped file.
! { dg-final { scan-tree-dump-times "_gfortran_compare_string" 0 "original" } }
! { dg-final { scan-tree-dump-times "_gfortran_copy_string" 0 "original" } }
! { dg-final { cleanup-tree-dump "original" } }
Index: trans.h
===================================================================
--- trans.h (revision 109308)
+++ trans.h (working copy)
@@ -268,6 +268,9 @@ void gfc_make_safe_expr (gfc_se * se);
/* Makes sure se is suitable for passing as a function string parameter. */
void gfc_conv_string_parameter (gfc_se * se);
+/* Compare two strings. */
+tree gfc_build_compare_string (tree, tree, tree, tree);
+
/* Add an item to the end of TREE_LIST. */
tree gfc_chainon_list (tree, tree);
Index: trans-intrinsic.c
===================================================================
--- trans-intrinsic.c (revision 109308)
+++ trans-intrinsic.c (working copy)
@@ -2267,13 +2267,17 @@ gfc_conv_intrinsic_strcmp (gfc_se * se,
{
tree type;
tree args;
+ tree arg2;
args = gfc_conv_intrinsic_function_args (se, expr);
- /* Build a call for the comparison. */
- se->expr = build_function_call_expr (gfor_fndecl_compare_string, args);
+ arg2 = TREE_CHAIN (TREE_CHAIN (args));
+
+ se->expr = gfc_build_compare_string (TREE_VALUE (args),
+ TREE_VALUE (TREE_CHAIN (args)), TREE_VALUE (arg2),
+ TREE_VALUE (TREE_CHAIN (arg2)));
type = gfc_typenode_for_spec (&expr->ts);
- se->expr = build2 (op, type, se->expr,
+ se->expr = fold_build2 (op, type, se->expr,
build_int_cst (TREE_TYPE (se->expr), 0));
}
Index: trans-expr.c
===================================================================
--- trans-expr.c (revision 109308)
+++ trans-expr.c (working copy)
@@ -901,7 +901,6 @@ gfc_conv_concat_op (gfc_se * se, gfc_exp
se->string_length = len;
}
-
/* Translates an op expression. Common (binary) cases are handled by this
function, others are passed on. Recursion is used in either case.
We use the fact that (op1.ts == op2.ts) (except for the power
@@ -1043,23 +1042,15 @@ gfc_conv_expr_op (gfc_se * se, gfc_expr
gfc_conv_expr (&rse, expr->value.op.op2);
gfc_add_block_to_block (&se->pre, &rse.pre);
- /* For string comparisons we generate a library call, and compare the return
- value with 0. */
if (checkstring)
{
gfc_conv_string_parameter (&lse);
gfc_conv_string_parameter (&rse);
- tmp = NULL_TREE;
- tmp = gfc_chainon_list (tmp, lse.string_length);
- tmp = gfc_chainon_list (tmp, lse.expr);
- tmp = gfc_chainon_list (tmp, rse.string_length);
- tmp = gfc_chainon_list (tmp, rse.expr);
-
- /* Build a call for the comparison. */
- lse.expr = build_function_call_expr (gfor_fndecl_compare_string, tmp);
- gfc_add_block_to_block (&lse.post, &rse.post);
+ lse.expr = gfc_build_compare_string (lse.string_length, lse.expr,
+ rse.string_length, rse.expr);
rse.expr = integer_zero_node;
+ gfc_add_block_to_block (&lse.post, &rse.post);
}
type = gfc_typenode_for_spec (&expr->ts);
@@ -1078,6 +1069,63 @@ gfc_conv_expr_op (gfc_se * se, gfc_expr
gfc_add_block_to_block (&se->post, &lse.post);
}
+/* If a string's length is one, we convert it to a single character. */
+
+static tree
+gfc_to_single_character (tree len, tree str)
+{
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (str)));
+
+ if (INTEGER_CST_P (len) && TREE_INT_CST_LOW (len) == 1
+ && TREE_INT_CST_HIGH (len) == 0)
+ {
+ str = fold_convert (pchar_type_node, str);
+ return build_fold_indirect_ref (str);
+ }
+
+ return NULL_TREE;
+}
+
+/* Compare two strings. If they are all single characters, the result is the
+ subtraction of them. Otherwise, we build a library call. */
+
+tree
+gfc_build_compare_string (tree len1, tree str1, tree len2, tree str2)
+{
+ tree sc1;
+ tree sc2;
+ tree type;
+ tree tmp;
+
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (str1)));
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (str2)));
+
+ type = gfc_get_int_type (gfc_default_integer_kind);
+
+ sc1 = gfc_to_single_character (len1, str1);
+ sc2 = gfc_to_single_character (len2, str2);
+
+ /* Deal with single character specially. */
+ if (sc1 != NULL_TREE && sc2 != NULL_TREE)
+ {
+ sc1 = fold_convert (type, sc1);
+ sc2 = fold_convert (type, sc2);
+ tmp = fold_build2 (MINUS_EXPR, type, sc1, sc2);
+ }
+ else
+ {
+ tmp = NULL_TREE;
+ tmp = gfc_chainon_list (tmp, len1);
+ tmp = gfc_chainon_list (tmp, str1);
+ tmp = gfc_chainon_list (tmp, len2);
+ tmp = gfc_chainon_list (tmp, str2);
+
+ /* Build a call for the comparison. */
+ tmp = build_function_call_expr (gfor_fndecl_compare_string, tmp);
+ }
+
+ return tmp;
+}
static void
gfc_conv_function_val (gfc_se * se, gfc_symbol * sym)
@@ -1818,6 +1866,17 @@ gfc_trans_string_copy (stmtblock_t * blo
tree slen, tree src)
{
tree tmp;
+ tree dsc;
+ tree ssc;
+
+ /* Deal with single character specially. */
+ dsc = gfc_to_single_character (dlen, dest);
+ ssc = gfc_to_single_character (slen, src);
+ if (dsc != NULL_TREE && ssc != NULL_TREE)
+ {
+ gfc_add_modify_expr (block, dsc, ssc);
+ return;
+ }
tmp = NULL_TREE;
tmp = gfc_chainon_list (tmp, dlen);