From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7655 invoked by alias); 5 Nov 2009 06:44:21 -0000 Received: (qmail 7635 invoked by uid 48); 5 Nov 2009 06:44:08 -0000 Date: Thu, 05 Nov 2009 06:44:00 -0000 Subject: [Bug c/41947] New: GCC Hexadecimal Floating point constant handling X-Bugzilla-Reason: CC Message-ID: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "ameya dot malondkar at tcs dot com" Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2009-11/txt/msg00399.txt.bz2 GCC accepts constructs such as : float p = 0x.p5; .As per C99 Standards the grammar for hexadecimal floating points is as follows : hexadecimal-floating-constant: hexadecimal-prefix hexadecimal-fractional-constant binary-exponent-part floating-suffix(opt) hexadecimal-prefix hexadecimal-digit-sequence binary-exponent-part floating-suffix(opt) hexadecimal-prefix: one of 0x 0X hexadecimal-fractional-constant: hexadecimal-digit-sequence(opt) . hexadecimal-digit-sequence hexadecimal-digit-sequence . binary-exponent-part: p sign(opt) digit-sequence P sign(opt) digit-sequence hexadecimal-digit-sequence: hexadecimal-digit hexadecimal-digit-sequence hexadecimal-digit floating-suffix: one of f l F L As per the grammar to my understanding, the above construct is invalid. Command : $ gcc -v -save-temps hexfloat.c Output : Using built-in specs. Target: i386-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-libgcj-multifile --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --enable-plugin --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic --host=i386-redhat-linux Thread model: posix gcc version 4.1.2 20070626 (Red Hat 4.1.2-14) /usr/libexec/gcc/i386-redhat-linux/4.1.2/cc1 -E -quiet -v hexfloat.c -mtune=generic -fpch-preprocess -o hexfloat.i ignoring nonexistent directory "/usr/lib/gcc/i386-redhat-linux/4.1.2/../../../../i386-redhat-linux/include" #include "..." search starts here: #include <...> search starts here: /usr/local/include /usr/lib/gcc/i386-redhat-linux/4.1.2/include /usr/include End of search list. /usr/libexec/gcc/i386-redhat-linux/4.1.2/cc1 -fpreprocessed hexfloat.i -quiet -dumpbase hexfloat.c -mtune=generic -auxbase hexfloat -version -o hexfloat.s GNU C version 4.1.2 20070626 (Red Hat 4.1.2-14) (i386-redhat-linux) compiled by GNU C version 4.1.2 20070626 (Red Hat 4.1.2-14). GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 6f8a93af44427a05901e7b3a98a7b357 as -V -Qy -o hexfloat.o hexfloat.s GNU assembler version 2.17.50.0.6-5.el5 (i386-redhat-linux) using BFD version 2.17.50.0.6-5.el5 20061020 /usr/libexec/gcc/i386-redhat-linux/4.1.2/collect2 --eh-frame-hdr -m elf_i386 --hash-style=gnu -dynamic-linker /lib/ld-linux.so.2 /usr/lib/gcc/i386-redhat-linux/4.1.2/../../../crt1.o /usr/lib/gcc/i386-redhat-linux/4.1.2/../../../crti.o /usr/lib/gcc/i386-redhat-linux/4.1.2/crtbegin.o -L/usr/lib/gcc/i386-redhat-linux/4.1.2 -L/usr/lib/gcc/i386-redhat-linux/4.1.2 -L/usr/lib/gcc/i386-redhat-linux/4.1.2/../../.. hexfloat.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/i386-redhat-linux/4.1.2/crtend.o /usr/lib/gcc/i386-redhat-linux/4.1.2/../../../crtn.o Preprocessed file : hexfloat.i # 1 "hexfloat.c" # 1 "" # 1 "" # 1 "hexfloat.c" int main(void) { float p = 0x.p5; return 0; } -- Summary: GCC Hexadecimal Floating point constant handling Product: gcc Version: 4.1.2 Status: UNCONFIRMED Severity: trivial Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: ameya dot malondkar at tcs dot com GCC build triplet: i386-redhat-linux GCC host triplet: i386-redhat-linux GCC target triplet: i386-redhat-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41947