Re: 2.4.0-test8-pre1 is quite bad / how about integrating Rik's VM

From: Chris Wedgwood (cw@f00f.org)
Date: Tue Sep 05 2000 - 20:28:45 EST


On Tue, Sep 05, 2000 at 08:54:40PM -0400, Alexander Viro wrote:

    If gcc will _ever_ fail to optimize away else in
            if (1) {
                    ...
            } else {
                    ...
            }
    - it's a bug in gcc. Sorry. Checking for the absence of code paths that would
    lead into block in question is trivial. I suspect that if you can demonstrate
    such example to gcc folks they will consider it as an obvious bug.

4al.o: file format elf32-i386

Disassembly of section .text:

00000000 <func>:

extern volatile int a;

int func()
{
   0: 55 push %ebp
   1: 89 e5 mov %esp,%ebp
        if(1)
                a = 1;
   3: c7 05 00 00 00 00 01 movl $0x1,0x0
   a: 00 00 00
                        5: R_386_32 a
   d: eb 0b jmp 1a <func+0x1a>
   f: 90 nop
        else
                a = 5;
  10: c7 05 00 00 00 00 05 movl $0x5,0x0
  17: 00 00 00
                        12: R_386_32 a
}
  1a: c9 leave
  1b: c3 ret
-
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