From:	"Alexei A. Frounze" <alex DOT fru AT mtu-net DOT ru>
Newsgroups:	comp.os.msdos.djgpp
Subject:	GCC BUG & 64-BIT INTEGERS PROBLEMS
Date:	Sun, 09 Apr 2000 02:38:23 +0400
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Hi guys!

I think I've found a real bug in GCC.

I define two 64-bit integer values as folows:
--------8<--------
long long A, B;
--------8<--------

then I assign something to them (actually I call a routine that stores
there 64-bit results of the RDTSC CPU instruction).

Then I try to shift these A and B values right:
--------8<--------
A>>=32;
B>>=33;
--------8<--------

But GCC generates the following faulty code (see attached screenshot from
builtin
RHIDE debugger/disassembler).

This means GCC doesn't handle shifts right properly. 

Shifts left seems to be okay. Addition and subtraction also work fine.

I've not tested multiplication and division, but there is a non-zero
probabilty that this can be faulty as well as shifts right.

Btw, is it possible to printf() 64-bit integers as well as 32-bit? How to make
RHIDE supporting 64-bit values too?

Ah.... Completely forgot... I use "gcc version 2.95.2 19991024
(release)" and "This is RHIDE Version 1.4.7.5. Modified by A.Pavenis
(Feb 8 2000 12:00:51)".

Any ideas???

Thanks.
Alexei A. Frounze
-----------------------------------------
Homepage: http://alexfru.chat.ru
Mirror:   http://members.xoom.com/alexfru
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êî[À]îîîîîîîîîîîîîîîîîîîîîîîî Disassembler window îîîîîîîîîîîîîîîîîîîîîîî4î[]î»
º 00005918:  mov    0xffffffcc(%ebp),%eax                      eax    00000011º
º 0000591b:  mov    0xffffffd0(%ebp),%edx                      Àecx    00000035º
º 0000591e:  mov    %eax,%ecx                                  ±edx    00005464º
º 00005920:  mov    %edx,%ebx                                  ±ebx    00008311º
º 00005922:  mov    %ebx,%ecx                                  ±esp    000cff98º
º 00005924:  sar    $0x1f,%ebx                                 ±ebp    000cffe0º
º 00005927:  mov    %ecx,0xffffffcc(%ebp)                      ±esi    00000054º
º 0000592a:  mov    %ebx,0xffffffd0(%ebp)                      ±edi    0001f41cº
º 0000592d:  mov    0xffffffc4(%ebp),%eax                      ±eip    00005918º
º 00005930:  mov    0xffffffc8(%ebp),%edx                      ±eflags 00000202º
º 00005933:  mov    %eax,%ecx                                  ±cs         0117º
º 00005935:  mov    %edx,%ebx                                  ±ss         011fº
º 00005937:  mov    %ebx,%ecx                                  ±ds         011fº
º 00005939:  sar    $0x1f,%ebx                                 ±es         011fº
º 0000593c:  sar    $0x1,%ecx                                  ±fs         010fº
º 0000593f:  mov    %ecx,0xffffffc4(%ebp)                      ±gs         012fº
º 00005942:  mov    %ebx,0xffffffc8(%ebp)                      ±               º
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