c-semantics.c (genrtl_while_stmt): Improve initial RTL generation when loop condition is known true, i.e.

* c-semantics.c (genrtl_while_stmt):  Improve initial RTL generation
	when loop condition is known true, i.e.  "while (1) { ... }".
	(genrtl_for_stmt): Similarly for "for" statements.

From-SVN: r61338
This commit is contained in:
Roger Sayle 2003-01-15 17:44:37 +00:00 committed by Roger Sayle
parent 03cd8aba32
commit 8cadeff16d
2 changed files with 24 additions and 12 deletions

View File

@ -1,3 +1,9 @@
2003-01-15 Roger Sayle <roger@eyesopen.com>
* c-semantics.c (genrtl_while_stmt): Improve initial RTL generation
when loop condition is known true, i.e. "while (1) { ... }".
(genrtl_for_stmt): Similarly for "for" statements.
2003-01-15 Roger Sayle <roger@eyesopen.com>
* real.c (real_sqrt): Return a bool result indicating whether

View File

@ -1,7 +1,7 @@
/* This file contains the definitions and documentation for the common
tree codes used in the GNU C and C++ compilers (see c-common.def
for the standard codes).
Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
Written by Benjamin Chelf (chelf@codesourcery.com).
This file is part of GCC.
@ -424,16 +424,20 @@ void
genrtl_while_stmt (t)
tree t;
{
tree cond;
tree cond = WHILE_COND (t);
emit_nop ();
emit_line_note (input_filename, lineno);
expand_start_loop (1);
genrtl_do_pushlevel ();
cond = expand_cond (WHILE_COND (t));
emit_line_note (input_filename, lineno);
expand_exit_loop_top_cond (0, cond);
genrtl_do_pushlevel ();
if (cond && !integer_nonzerop (cond))
{
cond = expand_cond (cond);
emit_line_note (input_filename, lineno);
expand_exit_loop_top_cond (0, cond);
genrtl_do_pushlevel ();
}
expand_stmt (WHILE_BODY (t));
@ -522,7 +526,7 @@ void
genrtl_for_stmt (t)
tree t;
{
tree cond;
tree cond = FOR_COND (t);
const char *saved_filename;
int saved_lineno;
@ -539,7 +543,6 @@ genrtl_for_stmt (t)
else
expand_start_loop (1);
genrtl_do_pushlevel ();
cond = expand_cond (FOR_COND (t));
/* Save the filename and line number so that we expand the FOR_EXPR
we can reset them back to the saved values. */
@ -547,12 +550,15 @@ genrtl_for_stmt (t)
saved_lineno = lineno;
/* Expand the condition. */
emit_line_note (input_filename, lineno);
if (cond)
expand_exit_loop_top_cond (0, cond);
if (cond && !integer_nonzerop (cond))
{
cond = expand_cond (cond);
emit_line_note (input_filename, lineno);
expand_exit_loop_top_cond (0, cond);
genrtl_do_pushlevel ();
}
/* Expand the body. */
genrtl_do_pushlevel ();
expand_stmt (FOR_BODY (t));
/* Expand the increment expression. */