This trivial patch fixes PR60991 by correcting the constant used to restore Y in one of the assembler template variants used in avr_out_store_psi. I've also added a testcase (modified from the original poster's code).
If ok, could someone commit please? I don't have commit access. It would be great if this was also committed to 4.9 and 4.8 branches as well. Regards Senthil gcc/ChangeLog 2014-05-12 Senthil Kumar Selvaraj <senthil_kumar.selva...@atmel.com> PR target/60991 * config/avr/avr.c (avr_out_store_psi): Use correct constant to restore Y. gcc/testsuite/ChangeLog 2014-05-12 Senthil Kumar Selvaraj <senthil_kumar.selva...@atmel.com> PR target/60991 * gcc.target/avr/pr60991.c: New testcase. diff --git gcc/config/avr/avr.c gcc/config/avr/avr.c index 536fe68..fc6c9f6 100644 --- gcc/config/avr/avr.c +++ gcc/config/avr/avr.c @@ -3999,7 +3999,7 @@ avr_out_store_psi (rtx insn, rtx *op, int *plen) "std Y+61,%A1" CR_TAB "std Y+62,%B1" CR_TAB "std Y+63,%C1" CR_TAB - "sbiw r28,%o0-60", op, plen, -5); + "sbiw r28,%o0-61", op, plen, -5); return avr_asm_len ("subi r28,lo8(-%o0)" CR_TAB "sbci r29,hi8(-%o0)" CR_TAB diff --git gcc/testsuite/gcc.target/avr/pr60991.c gcc/testsuite/gcc.target/avr/pr60991.c new file mode 100644 index 0000000..a09f42a --- /dev/null +++ gcc/testsuite/gcc.target/avr/pr60991.c @@ -0,0 +1,21 @@ +/* { dg-do run } */ +/* { dg-options "-O1" } */ + +/* This testcase (simplified from the original bug report) exposes + PR60991. The code generated for writing the __int24 value corrupts + the frame pointer if the offset is <= 63 + MAX_LD_OFFSET */ + +#include <stdlib.h> + +int main(void) +{ + volatile char junk[62]; + junk[0] = 5; + volatile __int24 staticConfig = 0; + + if (junk[0] != 5) + abort(); + + exit(0); + return 0; +}