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References: <bug-28685-1649@http.gcc.gnu.org/bugzilla/>
Subject: [Bug middle-end/28685] Multiple comparisons are not simplified
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From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
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------- Comment #4 from rguenth at gcc dot gnu dot org  2008-10-12 20:45 -------
Another similar, but yet different case:

int test(int a, int b)
{
  int lt = a < b;
  int eq = a == b;
  if (lt)
    return 1;
  return eq;
}

this is what we "optimize" it to:

test (int a, int b)
{
  int eq;

<bb 2>:
  eq_5 = a_2(D) == b_3(D);
  if (a_2(D) < b_3(D))
    goto <bb 4>;
  else
    goto <bb 3>;

<bb 3>:

<bb 4>:
  # eq_1 = PHI <1(2), eq_5(3)>
  return eq_1;


test:
        pushl   %ebp
        movl    $1, %eax
        movl    %esp, %ebp
        movl    12(%ebp), %edx
        cmpl    %edx, 8(%ebp)
        jl      .L3
        sete    %al
        movzbl  %al, %eax
.L3:
        popl    %ebp
        ret


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28685