[Bug target/36584] New: Stack is not aligned correctly in recursive function

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The example that will be attached in the next comment exhibits a problem with
recursive functions. It looks that gcc doesn't align stack correctly if the
only remaining call (after inlining?) in the function is the call to itself.

Compiling the test source with -O3 -m32 produces:

sbisect:

-4
-8      pushl   %ebp
        movl    %esp, %ebp
-12     pushl   %edi
-16     pushl   %esi
-20     pushl   %ebx
-196    subl    $176, %esp
        movl    32(%ebp), %eax
        ...
        movl    %eax, 4(%esp)
0xC4!!  call    sbisect
        movl    40(%ebp), %ecx
        ...

^^^^ offset from %esp at call site.

This violates assumption that %esp is aligned to 16 bytes at call sites. When
program recurses into the function, the frame gets unaligned, leading to
segfaults when aligned insns are used to access the frame.


-- 
           Summary: Stack is not aligned correctly in recursive function
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ubizjak at gmail dot com
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36584