If I compile this code for x86-64 I get:

$ cat jcc.c
extern int f(int x);
int g(int x) { return x > 3 ? f(x) : x; }

$ cc1 -quiet -O3 jcc.c -o -
...
g:
.LFB0:
        .cfi_startproc
        cmpl    $3, %edi
        jg      .L4
        movl    %edi, %eax
        ret
        .p2align 4,,10
        .p2align 3
.L4:
        jmp     f
        .cfi_endproc

This code would be simpler and shorter if the jg-to-jmp sequence was replaced with a single "jg f" instruction.

I'm using gcc built from svn trunk r207717.