Commit Message
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 <wdijkstr@arm.com>
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
---
Comments
Wilco Dijkstra <Wilco.Dijkstra@arm.com> 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 <wdijkstr@arm.com>
>
> 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 0000000000000000000000000000000000000000..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);
> +}
> +
@@ -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;
@@ -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")))
new file mode 100644
@@ -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);
+}
+