https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81305
Bug ID: 81305 Summary: [avr] avrtiny uses LDS for SREG in ISR routines which is out of range of LDS. Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: gjl at gcc dot gnu.org Target Milestone: --- This problem occurs with -O0 and -mmcu=avrtiny and "signal" or "interrupt" functions. Assembler messages: foo.s:331: Warning: operand out of range: 0x3f ISR prologue start reads: __vector_1: push r17 push r16 lds r16,63 ;; BUG push r16 ... Fix is to use IN no matter whether optimization is on.