[Bug ipa/111672] Inappropriate function splitting during pass_split_functions

["hkzhang455 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111672

--- Comment #2 from Hanke Zhang <hkzhang455 at gmail dot com> ---
(In reply to Andrew Pinski from comment #1)
> I cannot reproduce this on the trunk (or even in 12.3.0):
> 
> Split point at BB 3
>   header time: 1393.311190 header size: 33
>   split time: 2.226400 split size: 2
>   bbs: 3
>   SSA names to pass:
>   Refused: split size is smaller than call overhead
> found articulation at bb 7
> Split point at BB 7
>   header time: 1395.537590 header size: 35
>   split time: 0.000000 split size: 0
>   bbs: 7
>   SSA names to pass:
>   Refused: split size is smaller than call overhead

It's still the same bug in my place, and I'm trying to compile on another
computer, and the same happens. Note that, my host is x86_64-linux-gnu. Here is
part of my output infomation about function splitting optimization.

  gcc -O3 -flto -fdumo-tree-fnsplit test.c
  cat a-test.c.050t.fnsplit

;; Function printf (printf, funcdef_no=15, decl_uid=964, cgraph_uid=16,
symbol_order=15)

Not splitting: disregarding inline limits.
__attribute__((artificial, gnu_inline, always_inline))
__attribute__((nonnull (1), format (printf, 1, 2)))
int printf (const char * restrict __fmt)
{
  int _4;

  <bb 2> [local count: 1073741824]:
  _4 = __printf_chk (1, __fmt_2(D), __builtin_va_arg_pack ());
  return _4;

}



;; Function test_split_write (test_split_write, funcdef_no=39, decl_uid=3184,
cgraph_uid=40, symbol_order=43)



Splitting function at:
Split point at BB 3
  header time: 1393.311190 header size: 33
  split time: 2.428800 split size: 3
  bbs: 3
  SSA names to pass:
;; 1 loops found
;;
;; Loop 0
;;  header 0, latch 1
;;  depth 0, outer -1
;;  nodes: 0 1
Introduced new external node (puts/53).

Symbols to be put in SSA form
{ D.3222 }
Incremental SSA update started at block: 0
Number of blocks in CFG: 5
Number of blocks to update: 4 ( 80%)


;; 1 loops found
;;
;; Loop 0
;;  header 0, latch 1
;;  depth 0, outer -1
;;  nodes: 0 1 4 2 3
;; 4 succs { 2 }
;; 2 succs { 3 }
;; 3 succs { 1 }
int test_split_write.part.0 ()