[Bug c/31691] New: optimized code taking the wrong branch

[stephaniechc-gccbug at yahoo dot com]

The following example takes the "wrong_branch" when compiled with 
    gcc -O3 -fno-inline

gcc --version
gcc (GCC) 4.1.2
Copyright (C) 2006 Free Software Foundation, Inc.

===== example =====
#include <stdio.h>

static int get_kind(int v) {
    volatile int k = v;
    return k;
}

static int some_call(void)
{
    return 0;
}

static void wrong_branch(void) {
    printf("wrong_branch\n");
}

static int example(int arg)
{
    int  kind;
    kind = get_kind(arg);
    if (kind == 9 || kind == 10 || kind == 5) {
        if (some_call() == 0) {
            int tmp;
//            kind = get_kind(arg); // ok if this call is inserted
            if (kind == 9 || kind == 10) {
                tmp = arg;
            } else {
                wrong_branch();
            } /* if */
            return 0;
        }
    }
    return 0;
} 

int main(void) {
    int v = 10;
    example(v);
    return 0;
}

===================

The example prints "wrong_branch" when executed. If the second call to get_kind
is uncommented, nothing is printed (which is correct).

The generated assembly code is

===== example.s ======
example:
        save    %sp, -112, %sp
        call    get_kind, 0
         mov    %i0, %o0
        add     %o0, -9, %g1
        subcc   %g0, %g1, %g0
        subx    %g0, -1, %i0
        cmp     %g1, 1
        bleu    .LL11
         cmp    %o0, 5
        be      .LL11
         nop
.LL9:
        jmp     %i7+8
         restore %g0, 0, %o0
.LL11:
        call    some_call, 0
         nop
        cmp     %o0, 0
        bne     .LL9
         cmp    %i0, 0
        bne     .LL9
         nop
        call    wrong_branch, 0
         mov    0, %i0
        jmp     %i7+8
         restore
=======================


-- 
           Summary: optimized code taking the wrong branch
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: stephaniechc-gccbug at yahoo dot com
 GCC build triplet: sparc-sun-solaris2.8
  GCC host triplet: sparc-sun-solaris2.8+
GCC target triplet: sparc-sun-solaris2.8+


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31691