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Move and adjust PROBE_STACK reg definitions for aarch64

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The change moves the definitions of PROBE_STACK_FIRST_REG
and PROBE_STACK_SECOND_REG to a more appropriate place for such
items (here, in aarch64.md as suggested by Richard), and adjusts
their value from r9/r10 to r10/r11 to free r9 for a possibly
more general purpose (e.g. as a static chain at least on targets
which have a private use of r18, such as Windows or Vxworks).

2020-11-07  Olivier Hainque  <hainque@adacore.com>

gcc/
	* config/aarch64/aarch64.md: Define PROBE_STACK_FIRST_REGNUM
	and PROBE_STACK_SECOND_REGNUM constants, designating r10/r11.
	Replacements for the PROBE_STACK_FIRST/SECOND_REG constants in
	aarch64.c.
	* config/aarch64/aarch64.c (PROBE_STACK_FIRST_REG): Remove.
	(PROBE_STACK_SECOND_REG): Remove.
	(aarch64_emit_probe_stack_range): Adjust to the _REG -> _REGNUM
	suffix update for PROBE_STACK register numbers.
This commit is contained in:
Olivier Hainque 2019-12-13 09:09:18 +00:00
parent 58c9de4654
commit 5773855c3f
2 changed files with 9 additions and 6 deletions
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8
gcc/config/aarch64/aarch64.c
View file

@ -6272,10 +6272,6 @@ aarch64_libgcc_cmp_return_mode (void)
#error Cannot use simple address calculation for stack probing
#endif
/* The pair of scratch registers used for stack probing. */
#define PROBE_STACK_FIRST_REG R9_REGNUM
#define PROBE_STACK_SECOND_REG R10_REGNUM
/* Emit code to probe a range of stack addresses from FIRST to FIRST+POLY_SIZE,
inclusive. These are offsets from the current stack pointer. */
@ -6289,7 +6285,7 @@ aarch64_emit_probe_stack_range (HOST_WIDE_INT first, poly_int64 poly_size)
return;
}
rtx reg1 = gen_rtx_REG (Pmode, PROBE_STACK_FIRST_REG);
rtx reg1 = gen_rtx_REG (Pmode, PROBE_STACK_FIRST_REGNUM);
/* See the same assertion on PROBE_INTERVAL above. */
gcc_assert ((first % ARITH_FACTOR) == 0);
@ -6347,7 +6343,7 @@ aarch64_emit_probe_stack_range (HOST_WIDE_INT first, poly_int64 poly_size)
equality test for the loop condition. */
else
{
rtx reg2 = gen_rtx_REG (Pmode, PROBE_STACK_SECOND_REG);
rtx reg2 = gen_rtx_REG (Pmode, PROBE_STACK_SECOND_REGNUM);
/* Step 1: round SIZE to the previous multiple of the interval. */

7
gcc/config/aarch64/aarch64.md
View file

@ -111,6 +111,13 @@
;; "FFR token": a fake register used for representing the scheduling
;; restrictions on FFR-related operations.
(FFRT_REGNUM 85)
;; The pair of scratch registers used for stack probing with -fstack-check.
;; Leave R9 alone as a possible choice for the static chain.
;; Note that the use of these registers is mutually exclusive with the use
;; of STACK_CLASH_SVE_CFA_REGNUM, which is for -fstack-clash-protection
;; rather than -fstack-check.
(PROBE_STACK_FIRST_REGNUM 10)
(PROBE_STACK_SECOND_REGNUM 11)
;; Scratch register used by stack clash protection to calculate
;; SVE CFA offsets during probing.
(STACK_CLASH_SVE_CFA_REGNUM 11)