Wilco Dijkstra writes:
> The stack protector implementation hides symbols in a const unspec, which
> means
> movdi/movsi patterns must always support const on symbol operands and
> explicitly
> strip away the unspec. Do this for the recently added GOT alternatives. Add a
> test to ensure stack-protector tests GOT accesses as well.
>
> Passes bootstrap and regress. OK for commit?
>
> 2021-11-05 Wilco Dijkstra
>
> PR target/103085
> * config/aarch64/aarch64.c (aarch64_mov_operand_p): Strip the salt
> first.
> * config/aarch64/constraints.md: Support const in Usw.
>
> * gcc.target/aarch64/pr103085.c: New test
OK, thanks.
Richard
> ---
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index
> 430ea036a7be4da842fd08998923a3462457dbfd..39de231d8ac6d10362cdd2b48eb9bd9de60c6703
> 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -20155,12 +20155,14 @@ aarch64_mov_operand_p (rtx x, machine_mode mode)
>return aarch64_simd_valid_immediate (x, NULL);
> }
>
> + /* Remove UNSPEC_SALT_ADDR before checking symbol reference. */
> + x = strip_salt (x);
> +
>/* GOT accesses are valid moves. */
>if (SYMBOL_REF_P (x)
>&& aarch64_classify_symbolic_expression (x) == SYMBOL_SMALL_GOT_4G)
> return true;
>
> - x = strip_salt (x);
>if (SYMBOL_REF_P (x) && mode == DImode && CONSTANT_ADDRESS_P (x))
> return true;
>
> diff --git a/gcc/config/aarch64/constraints.md
> b/gcc/config/aarch64/constraints.md
> index
> 70ca66070217d06f974b18f7690326bc329fed89..da5438e7ce254272eb10e9ac60d5367c46635e84
> 100644
> --- a/gcc/config/aarch64/constraints.md
> +++ b/gcc/config/aarch64/constraints.md
> @@ -152,10 +152,11 @@ (define_constraint "Usa"
> (match_test "aarch64_symbolic_address_p (op)")
> (match_test "aarch64_mov_operand_p (op, GET_MODE (op))")))
>
> +;; const is needed here to support UNSPEC_SALT_ADDR.
> (define_constraint "Usw"
>"@internal
> A constraint that matches a small GOT access."
> - (and (match_code "symbol_ref")
> + (and (match_code "const,symbol_ref")
> (match_test "aarch64_classify_symbolic_expression (op)
> == SYMBOL_SMALL_GOT_4G")))
>
> diff --git a/gcc/testsuite/gcc.target/aarch64/pr103085.c
> b/gcc/testsuite/gcc.target/aarch64/pr103085.c
> new file mode 100644
> index
> ..dbc9c15b71f224b3c7dec0cca5655a31adc207f6
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/pr103085.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fstack-protector-strong -fPIC" } */
> +
> +void g(int*);
> +void
> +f (int x)
> +{
> + int arr[10];
> + g (arr);
> +}
> +
