Package: gcc-4.3-mips-linux-gnu
Version: 4.3.5-4
Severity: grave
Tags: upstream
Justification: renders package unusable
With compile options
-O0 -static -DMIPS -mips1 -mabi=32 -msoft-float -mno-memcpy
gcc produces incorrect code for division (and I suppose, %) from C.
Test code can be simply:
main() {
int a,b,c;
c = a/b;
}
compile to assembler with above flags. Read, or compile to object code
and disassemble. The eyes-on read shows:
bne $3,$0,1f #!!! ergh! Should be beq
div $0,$2,$3
break 7
1:
mflo $2
The divide is protected by a "branch around the divide if the denominator
is NOT equal to zero". It should be "IS equal to zero".
Checking the disassembly of the object code shows:
1c: 14600002 bnez v1,28 <main+0x28> (File Offset: 0x68)
20: 0043001a div zero,v0,v1
24: 0007000d break 0x7
28: 00001012 mflo v0
which is as indicated by the assembler source.
No, the problem does not go away if the result from the division
is used in the source code. I haven't tested with optimization but
I see no reason to suppose that peephole optimization filters
after the generation will patch this up (except where they excise it).
-- System Information:
LSB Version:
core-2.0-ia32:core-2.0-noarch:core-3.0-ia32:core-3.0-noarch:core-3.1-ia32:core-3.1-noarch:core-3.2-ia32:core-3.2-noarch:cxx-3.0-ia32:cxx-3.0-noarch:cxx-3.1-ia32:cxx-3.1-noarch:cxx-3.2-ia32:cxx-3.2-noarch:desktop-3.1-ia32:desktop-3.1-noarch:desktop-3.2-ia32:desktop-3.2-noarch:graphics-2.0-ia32:graphics-2.0-noarch:graphics-3.0-ia32:graphics-3.0-noarch:graphics-3.1-ia32:graphics-3.1-noarch:graphics-3.2-ia32:graphics-3.2-noarch:languages-3.2-ia32:languages-3.2-noarch:multimedia-3.2-ia32:multimedia-3.2-noarch:printing-3.2-ia32:printing-3.2-noarch:qt4-3.1-ia32:qt4-3.1-noarch
Distributor ID: Ubuntu NO It's NOT! SOmebody please tell me where that is!
Description: Ubuntu 8.04.1 NYAAAA! No it's not. This is Debian Unstable.
Release: 8.04 Nix.
Codename: hardyArchitecture: i386 (i686) Nonsense. Where that come from?
Kernel: Linux 2.6.31.2-SMP (SMP w/1 CPU core; PREEMPT)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C)
Shell: /bin/sh linked to /bin/bash
Versions of packages gcc-4.3-mips-linux-gnu depends on:
ii binutils-mips-linux-gnu 2.20.1-15 The GNU binary utilities, for mips
ii cpp-4.3-mips-linux-gnu 4.3.5-4 The GNU C preprocessor
ii gcc-4.3-mips-linux-gnu-base 4.3.5-4 The GNU Compiler Collection (base
ii libc6 2.11.2-7 Embedded GNU C Library: Shared lib
ii libgcc1-mips-cross 1:4.4.5-10 GCC support library (for cross-com
ii libgomp1 4.4.5-10 GCC OpenMP (GOMP) support library
Versions of packages gcc-4.3-mips-linux-gnu recommends:
ii libc6-dev-mips-cross 2.11.2-2 Embedded GNU C Library: Developmen
Versions of packages gcc-4.3-mips-linux-gnu suggests:
pn gcc-4.3-doc <none> (no description available)
pn gcc-4.3-locales <none> (no description available)
pn gcc-4.3-multilib-mips-linux-g <none> (no description available)
pn libgcc1-dbg-mips-cross <none> (no description available)
pn libgomp1-dbg-mips-cross <none> (no description available)
pn libmudflap0-4.3-dev-mips-cros <none> (no description available)
pn libmudflap0-dbg-mips-cross <none> (no description available)
-- no debconf information
--
To UNSUBSCRIBE, email to [email protected]
with a subject of "unsubscribe". Trouble? Contact [email protected]
