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
defined to something returning true instead.
Richard.
> Ok for trunk and backporting to 13 and 12 branches?
>
> Regards
> Senthil
>
> PR target/105523
>
> gcc/ChangeLog:
>
> * config/avr/avr.cc (avr_option_override): Set
> param_min_pagesize to 0.
>
> 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..3b862f4e4ac 100644
> --- a/gcc/config/avr/avr.cc
> +++ b/gcc/config/avr/avr.cc
> @@ -56,6 +56,7 @@
> #include "tree-pass.h"
> #include "print-rtl.h"
> #include "rtl-iter.h"
> +#include "opts.h"
>
> /* This file should be included last. */
> #include "target-def.h"
> @@ -769,6 +770,9 @@ avr_option_override (void)
> avr_gasisr_prologues = 0;
> #endif
>
> + SET_OPTION_IF_UNSET (&global_options, &global_options_set,
> + param_min_pagesize, 0);
> +
> if (!avr_set_core_architecture())
> return;
>
> 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;
> +}
>
