This is a duplicate of bug 1601, which I can't reopen.

This bug is still present on 4.1.2-13 (RedHat, 20070626) and 3.4.6-3 (RedHat 20060404). Looking at the produced assembly, f2 and fun are both produced; the assembly should only produce fun and inline both f1 and f2. I havn't tested it on 4.2.1 yet, but I'm reopening it because it was reported as fixed years ago. I'm compiling the test given below with:
gcc -c -O3 --save-temps inline_test.c

How-To-Repeat (from bug 1601):
static inline int
f1( int (*f)(int y), int q )
{
  return( (*f)( q ) );
}

static inline int
f2( int z )
{
  return( z ^ 32 );
}

int fun( int x )
{
  return( f1( &f2, x ) );
}