On Wed, Apr 26, 2023 at 3:15 PM Richard Biener via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > On Wed, Apr 26, 2023 at 11:42 AM Richard Biener > <richard.guent...@gmail.com> wrote: > > > > On Wed, Apr 26, 2023 at 11:01 AM SenthilKumar.Selvaraj--- via > > Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > > > > > Hi, > > > > > > This patch fixes PR 105523 by setting param_min_pagesize to 0 for the > > > avr target. For this target, zero and offsets from zero are perfectly > > > valid addresses, and the default value of param_min_pagesize ends up > > > triggering warnings on valid memory accesses. > > > > I think the proper configuration is to have > > DEFAULT_ADDR_SPACE_ZERO_ADDRESS_VALID > > Err, TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID
That worked. Ok for trunk and backporting to 13 and 12 branches (pending regression testing)? Regards, Senthil PR 105523 gcc/ChangeLog: * config/avr/avr.cc (avr_addr_space_zero_address_valid): (TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID): Return true. gcc/testsuite/ChangeLog: * gcc.target/avr/pr105523.c: New test. diff --git a/gcc/config/avr/avr.cc b/gcc/config/avr/avr.cc index c193430cf07..5439eb8e55c 100644 --- a/gcc/config/avr/avr.cc +++ b/gcc/config/avr/avr.cc @@ -9788,6 +9788,16 @@ avr_addr_space_diagnose_usage (addr_space_t as, location_t loc) (void) avr_addr_space_supported_p (as, loc); } +/* Implement `TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID. Zero is a valid + address in all address spaces. Even in ADDR_SPACE_FLASH1 etc., + a zero address is valid and means 0x<RAMPZ>0000, where RAMPZ is + set to the appropriate segment value. */ + +static bool +avr_addr_space_zero_address_valid (addr_space_t as) +{ + return true; +} /* Look if DECL shall be placed in program memory space by means of attribute `progmem' or some address-space qualifier. @@ -14688,6 +14698,9 @@ avr_float_lib_compare_returns_bool (machine_mode mode, enum rtx_code) #undef TARGET_ADDR_SPACE_DIAGNOSE_USAGE #define TARGET_ADDR_SPACE_DIAGNOSE_USAGE avr_addr_space_diagnose_usage +#undef TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID +#define TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID avr_addr_space_zero_address_valid + #undef TARGET_MODE_DEPENDENT_ADDRESS_P #define TARGET_MODE_DEPENDENT_ADDRESS_P avr_mode_dependent_address_p diff --git a/gcc/testsuite/gcc.target/avr/pr105523.c b/gcc/testsuite/gcc.target/avr/pr105523.c new file mode 100644 index 00000000000..fbbf7bf4422 --- /dev/null +++ b/gcc/testsuite/gcc.target/avr/pr105523.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-Os -Wall" } */ + +/* Verify no "array subscript 0 is outside array bounds of" is generated + for accessing memory addresses in the 0-4096 range. */ + +typedef __UINT8_TYPE__ uint8_t; + +#define SREG (*(volatile uint8_t*) (0x3F + __AVR_SFR_OFFSET__ )) + +void bar (void) +{ + SREG = 0; +}