Test gcc.c-torture/execute/memcpy-bi.c (-O2) failed for attiny40 device. Cause seems to be in "load from memory" as it is not restoring base register after load instructions generated.
Function avr_out_load_psi_reg_no_disp_tiny in avr.c: It returns just after emitting instructions to load from memory to registers. It is important to restore the base register if it is not marked dead/unused after that insn. Code to restore base register is present already. Below patch let the function do the restore before return. If OK, could someone commit? I do not have commit access. diff --git a/gcc/config/avr/avr.c b/gcc/config/avr/avr.c index 4e83de8..b653858 100644 --- a/gcc/config/avr/avr.c +++ b/gcc/config/avr/avr.c @@ -4365,9 +4365,9 @@ avr_out_load_psi_reg_no_disp_tiny (rtx insn, rtx *op, int *plen) } else { - return avr_asm_len ("ld %A0,%1+" CR_TAB - "ld %B0,%1+" CR_TAB - "ld %C0,%1", op, plen, -3); + avr_asm_len ("ld %A0,%1+" CR_TAB + "ld %B0,%1+" CR_TAB + "ld %C0,%1", op, plen, -3); if (reg_dest != reg_base - 2 && !reg_unused_after (insn, base)) Regards, Pitchumani gcc/ChangeLog 2015-05-19 Pitchumani Sivanupandi <pitchuman...@atmel.com> * config/avr/avr.c (avr_out_load_psi_reg_no_disp_tiny): Restore base register if not marked dead/unused, before return.