On 4/25/07, Joerg Wunsch <[EMAIL PROTECTED]> wrote:
As Ian Lance Taylor wrote:
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31528
> The relevant code is in opts.c:
> if (optimize_size)
> {
> /* Inlining of very small functions usually reduces total size. */
> set_param_value ("max-inline-insns-single", 5);
> set_param_value ("max-inline-insns-auto", 5);
> flag_inline_functions = 1;
> Inlining has changed considerably since then, and it is possible
> that these parameter values are no longer appropriate. The reports
> at the time indicate space savings.
Thanks for telling me where to look for it, Ian! It's really
appreciated.
I made a first attempt on lowering max-inline-insns-auto from 5 to 3.
I did some initial testing (using the C program and shell script in
the attachment), on a recent GCC tree built for both, the AVR target
as well as my host's native i386 target. This appears to be at a
break-even to me:
I'd rather remove this "hack" and use the inliners code size estimator, like
that patch from early 2005 (attached)...
Richard.
2005-03-02 Richard Guenther <[EMAIL PROTECTED]>
* opts.c (decode_options): Do not fiddle with inlining
parameters in case of optimizing for size.
* cgraphunit.c (cgraph_check_inline_limits): If optimizing
for size make sure we do not grow the unit-size by inlining.
(cgraph_decide_recursive_inlining): Likewise.
2005-03-02 Richard Guenther <[EMAIL PROTECTED]>
* opts.c (decode_options): Do not fiddle with inlining
parameters in case of optimizing for size.
* cgraphunit.c (cgraph_check_inline_limits): If optimizing
for size make sure we do not grow the unit-size by inlining.
(cgraph_decide_recursive_inlining): Likewise.
Index: opts.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/opts.c,v
retrieving revision 1.94
diff -c -3 -p -r1.94 opts.c
*** opts.c 24 Feb 2005 09:24:13 -0000 1.94
--- opts.c 2 Mar 2005 13:10:58 -0000
*************** decode_options (unsigned int argc, const
*** 572,580 ****
if (optimize_size)
{
! /* Inlining of very small functions usually reduces total size. */
! set_param_value ("max-inline-insns-single", 5);
! set_param_value ("max-inline-insns-auto", 5);
flag_inline_functions = 1;
/* We want to crossjump as much as possible. */
--- 572,579 ----
if (optimize_size)
{
! /* Inlining of functions reducing size is a good idea regardless
! of them being declared inline. */
flag_inline_functions = 1;
/* We want to crossjump as much as possible. */
Index: cgraphunit.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cgraphunit.c,v
retrieving revision 1.93.2.1
diff -c -3 -p -r1.93.2.1 cgraphunit.c
*** cgraphunit.c 2 Mar 2005 10:10:30 -0000 1.93.2.1
--- cgraphunit.c 2 Mar 2005 13:10:58 -0000
*************** cgraph_check_inline_limits (struct cgrap
*** 1184,1189 ****
--- 1189,1201 ----
limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100;
newsize = cgraph_estimate_size_after_inlining (times, to, what);
+ if (optimize_size
+ && newsize > to->global.insns)
+ {
+ if (reason)
+ *reason = N_("optimizing for size");
+ return false;
+ }
if (newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS)
&& newsize > limit)
{
*************** cgraph_decide_recursive_inlining (struct
*** 1279,1284 ****
--- 1291,1297 ----
struct cgraph_node *master_clone;
int depth = 0;
int n = 0;
+ int newsize;
if (DECL_DECLARED_INLINE_P (node->decl))
{
*************** cgraph_decide_recursive_inlining (struct
*** 1287,1294 ****
}
/* Make sure that function is small enough to be considered for inlining. */
! if (!max_depth
! || cgraph_estimate_size_after_inlining (1, node, node) >= limit)
return;
lookup_recursive_calls (node, node, &first_call, &last_call);
if (!first_call)
--- 1300,1309 ----
}
/* Make sure that function is small enough to be considered for inlining. */
! newsize = cgraph_estimate_size_after_inlining (1, node, node);
! if (! max_depth
! || newsize >= limit
! || (optimize_size && newsize > node->global.insns))
return;
lookup_recursive_calls (node, node, &first_call, &last_call);
if (!first_call)
