[Bug tree-optimization/45216] Rotate expressions not recognized at tree level

[mickflemm at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45216

Nick Kossifidis <mickflemm at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mickflemm at gmail dot com

--- Comment #7 from Nick Kossifidis <mickflemm at gmail dot com> 2012-12-01 01:37:35 UTC ---
In my case it does detect an even more complex scenario but it doesn't detect
it when using integer typedefs from <sys/types.h>, more specifically:

unsigned long rotate_left(unsigned long a, unsigned int shift)
{
        return a << shift | a >> (sizeof(a) * 8 - shift);
}

results

080483d4 <rotate_left>:
 80483d4:    55                       push   %ebp
 80483d5:    89 e5                    mov    %esp,%ebp
 80483d7:    53                       push   %ebx
 80483d8:    8b 45 0c                 mov    0xc(%ebp),%eax
 80483db:    8b 55 08                 mov    0x8(%ebp),%edx
 80483de:    89 d3                    mov    %edx,%ebx
 80483e0:    89 c1                    mov    %eax,%ecx
 80483e2:    d3 c3                    rol    %cl,%ebx
 80483e4:    89 d8                    mov    %ebx,%eax
 80483e6:    5b                       pop    %ebx
 80483e7:    5d                       pop    %ebp
 80483e8:    c3                       ret  

but

u_int64_t rotate_left(u_int64_t a, u_int32_t shift)
{
        return a << shift | a >> (sizeof(a) * 8 - shift);
}

results

080483d4 <rotate_left>:
 80483d4:    55                       push   %ebp
 80483d5:    89 e5                    mov    %esp,%ebp
 80483d7:    56                       push   %esi
 80483d8:    53                       push   %ebx
 80483d9:    83 ec 10                 sub    $0x10,%esp
 80483dc:    8b 45 08                 mov    0x8(%ebp),%eax
 80483df:    89 45 f0                 mov    %eax,-0x10(%ebp)
 80483e2:    8b 45 0c                 mov    0xc(%ebp),%eax
 80483e5:    89 45 f4                 mov    %eax,-0xc(%ebp)
 80483e8:    8b 45 f0                 mov    -0x10(%ebp),%eax
 80483eb:    8b 55 f4                 mov    -0xc(%ebp),%edx
 80483ee:    8b 4d 10                 mov    0x10(%ebp),%ecx
 80483f1:    89 c3                    mov    %eax,%ebx
 80483f3:    89 d6                    mov    %edx,%esi
 80483f5:    0f a5 de                 shld   %cl,%ebx,%esi
 80483f8:    d3 e3                    shl    %cl,%ebx
 80483fa:    f6 c1 20                 test   $0x20,%cl
 80483fd:    74 04                    je     8048403 <ed_rotate_left+0x2f>
 80483ff:    89 de                    mov    %ebx,%esi
 8048401:    31 db                    xor    %ebx,%ebx
 8048403:    b9 40 00 00 00           mov    $0x40,%ecx
 8048408:    2b 4d 10                 sub    0x10(%ebp),%ecx
 804840b:    0f ad d0                 shrd   %cl,%edx,%eax
 804840e:    d3 ea                    shr    %cl,%edx
 8048410:    f6 c1 20                 test   $0x20,%cl
 8048413:    74 04                    je     8048419 <ed_rotate_left+0x45>
 8048415:    89 d0                    mov    %edx,%eax
 8048417:    31 d2                    xor    %edx,%edx
 8048419:    89 c1                    mov    %eax,%ecx
 804841b:    09 d9                    or     %ebx,%ecx
 804841d:    89 4d e8                 mov    %ecx,-0x18(%ebp)
 8048420:    89 d1                    mov    %edx,%ecx
 8048422:    09 f1                    or     %esi,%ecx
 8048424:    89 4d ec                 mov    %ecx,-0x14(%ebp)
 8048427:    8b 45 e8                 mov    -0x18(%ebp),%eax
 804842a:    8b 55 ec                 mov    -0x14(%ebp),%edx
 804842d:    83 c4 10                 add    $0x10,%esp
 8048430:    5b                       pop    %ebx
 8048431:    5e                       pop    %esi
 8048432:    5d                       pop    %ebp
 8048433:    c3                       ret  

Here are the typedefs from <sys/types.h>:

typedef unsigned int u_int32_t __attribute__ ((__mode__ (__SI__)));
typedef unsigned int u_int64_t __attribute__ ((__mode__ (__DI__)));

I also tried with u_int32_t/u_int16_t and other combinations but I get the same
results.

gcc version 4.5.4 (Gentoo 4.5.4 p1.0, pie-0.4.7)