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From: "amker.cheng at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/51867] GCC generates inconsistent code for same sources calling builtin calls, like sqrtf
Date: Mon, 16 Jan 2012 10:19:00 -0000	[thread overview]
Message-ID: <bug-51867-4-W37lnksODW@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-51867-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51867

--- Comment #1 from amker.cheng <amker.cheng at gmail dot com> 2012-01-16 10:15:59 UTC ---
The cause is in function expand_builtin, gcc checks following conditions:
----------------------------------------------
 /* When not optimizing, generate calls to library functions for a certain
    set of builtins.  */
 if (!optimize
     && !called_as_built_in (fndecl)
     && DECL_ASSEMBLER_NAME_SET_P (fndecl)
     && fcode != BUILT_IN_ALLOCA
     && fcode != BUILT_IN_ALLOCA_WITH_ALIGN
     && fcode != BUILT_IN_FREE)
   return expand_call (exp, target, ignore);

The control flow is:
1, DECL_ASSEMBLER_NAME_SET_P (fndecl) is false at the first time when compiling
a;
2, It is then set in following codes when expanding sqrtf call in function a;
3, When compiling function b, gcc checks DECL_ASSEMBLER_NAME_SET_P (fndecl)
    again and this time it's true;


  reply	other threads:[~2012-01-16 10:16 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-16 10:15 [Bug middle-end/51867] New: " amker.cheng at gmail dot com
2012-01-16 10:19 ` amker.cheng at gmail dot com [this message]
2012-01-16 14:45 ` [Bug middle-end/51867] " rguenth at gcc dot gnu.org
2012-01-17 10:43 ` amker.cheng at gmail dot com
2012-02-09  9:38 ` amker at gcc dot gnu.org
2012-06-18  2:03 ` amker.cheng at gmail dot com
2022-01-06  3:42 ` pinskia at gcc dot gnu.org

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