[avr-libc-dev] weird branch code in gcc-4.5.1?

[Rolf Ebert]

I am wondering if I'm doing something totally wrong or if there is an 
issue with gcc-4.5.1 (yes, Eric, you have warned me)

disassembling the typical putc() from the final elf files shows:

 11a:   90 91 c0 00     lds     r25, 0x00C0
 11e:   95 ff           sbrs    r25, 5
 120:   03 c0           rjmp    .+6     ; <-- weird?
 122:   80 93 c6 00     sts     0x00C6, r24
 126:   08 95           ret
 128:   ff cf           rjmp    .-2     ; <-- weird?


The corresponding code from gcc-4.3.3 was inlined and looks like:

  d0:   80 91 c0 00     lds     r24, 0x00C0
  d4:   85 ff           sbrs    r24, 5
  d6:   fc cf           rjmp    .-8
  d8:   90 93 c6 00     sts     0x00C6, r25


The corresponding source code is in Ada:
      while UCSRA_Bits (UDRE_Bit) = False loop null; end loop;
      UDR := Data;

I did not yet test a corresponding C code. I just want to ask if 
somebody had seen an issue like that before.

   Rolf