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From: "aph at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/50773] float values are printed with greater precision than the float data type has when given as an argument to printf() Date: Tue, 18 Oct 2011 10:21:00 -0000 [thread overview] Message-ID: <bug-50773-4-v7TdmQbHoQ@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-50773-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50773 Andrew Haley <aph at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |aph at gcc dot gnu.org --- Comment #2 from Andrew Haley <aph at gcc dot gnu.org> 2011-10-18 10:20:40 UTC --- This is definitely a C front-end bug. If you look at the gimple dump, you can see that the literal 268517138.f isn't being correctly truncated, but instead the constant 2.68517138e+8 is being used instead: main (int argc, char * * argv) { double D.2549; const char * restrict D.2550; double D.2551; const char * restrict D.2552; int D.2553; float a; a = 2.68517152e+8; D.2549 = (double) a; D.2550 = (const char * restrict) &" 268517138.f = %f\t%f\n"[0]; printf (D.2550, 2.68517138e+8, D.2549); C++ FE does it correctly: int main(int, char**) (int argc, char * * argv) { double D.2226; double D.2227; double D.2228; double D.2229; int D.2230; { float a; a = 2.68517152e+8; D.2226 = (double) a; D.2227 = (double) 2.68517152e+8; printf (&" 268517138.f = %f\t%f\n"[0], D.2227, D.2226);
next prev parent reply other threads:[~2011-10-18 10:21 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-10-18 9:34 [Bug c/50773] New: " momchil at xaxo dot eu 2011-10-18 10:06 ` [Bug c/50773] " rguenth at gcc dot gnu.org 2011-10-18 10:21 ` aph at gcc dot gnu.org [this message] 2011-10-18 10:43 ` rguenth at gcc dot gnu.org 2011-10-18 14:50 ` joseph at codesourcery dot com 2014-04-18 20:42 ` mpolacek at gcc dot gnu.org
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