crosstool-ng/packages/gcc/9.5.0/0022-aarch64-Add-bytes_below_hard_fp-to-frame-info.patch

190 lines
8.4 KiB
Diff

From 347487fffa0266d43bf18f1f91878410881f596e Mon Sep 17 00:00:00 2001
From: Richard Sandiford <richard.sandiford@arm.com>
Date: Fri, 16 Jun 2023 16:55:12 +0100
Subject: [PATCH 22/30] aarch64: Add bytes_below_hard_fp to frame info
The frame layout code currently hard-codes the assumption that
the number of bytes below the saved registers is equal to the
size of the outgoing arguments. This patch abstracts that
value into a new field of aarch64_frame.
gcc/
* config/aarch64/aarch64.h (aarch64_frame::bytes_below_hard_fp): New
field.
* config/aarch64/aarch64.c (aarch64_layout_frame): Initialize it,
and use it instead of crtl->outgoing_args_size.
(aarch64_get_separate_components): Use bytes_below_hard_fp instead
of outgoing_args_size.
(aarch64_process_components): Likewise.
---
gcc/config/aarch64/aarch64.c | 50 +++++++++++++++++++-----------------
gcc/config/aarch64/aarch64.h | 6 ++++-
2 files changed, 32 insertions(+), 24 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index e9dad682738f..25cf10cc4b94 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -4684,6 +4684,8 @@ aarch64_layout_frame (void)
last_fp_reg = regno;
}
+ cfun->machine->frame.bytes_below_hard_fp = crtl->outgoing_args_size;
+
if (cfun->machine->frame.emit_frame_chain)
{
/* FP and LR are placed in the linkage record. */
@@ -4751,11 +4753,11 @@ aarch64_layout_frame (void)
STACK_BOUNDARY / BITS_PER_UNIT);
/* Both these values are already aligned. */
- gcc_assert (multiple_p (crtl->outgoing_args_size,
+ gcc_assert (multiple_p (cfun->machine->frame.bytes_below_hard_fp,
STACK_BOUNDARY / BITS_PER_UNIT));
cfun->machine->frame.frame_size
= (cfun->machine->frame.hard_fp_offset
- + crtl->outgoing_args_size);
+ + cfun->machine->frame.bytes_below_hard_fp);
cfun->machine->frame.locals_offset = cfun->machine->frame.saved_varargs_size;
@@ -4775,23 +4777,23 @@ aarch64_layout_frame (void)
cfun->machine->frame.initial_adjust = cfun->machine->frame.frame_size;
else if (cfun->machine->frame.frame_size.is_constant (&const_size)
&& const_size < max_push_offset
- && known_eq (crtl->outgoing_args_size, 0))
+ && known_eq (cfun->machine->frame.bytes_below_hard_fp, 0))
{
- /* Simple, small frame with no outgoing arguments:
+ /* Simple, small frame with no data below the saved registers.
stp reg1, reg2, [sp, -frame_size]!
stp reg3, reg4, [sp, 16] */
cfun->machine->frame.callee_adjust = const_size;
}
- else if (known_lt (crtl->outgoing_args_size
+ else if (known_lt (cfun->machine->frame.bytes_below_hard_fp
+ cfun->machine->frame.saved_regs_size, 512)
&& !(cfun->calls_alloca
&& known_lt (cfun->machine->frame.hard_fp_offset,
max_push_offset)))
{
- /* Frame with small outgoing arguments:
+ /* Frame with small area below the saved registers:
sub sp, sp, frame_size
- stp reg1, reg2, [sp, outgoing_args_size]
- stp reg3, reg4, [sp, outgoing_args_size + 16] */
+ stp reg1, reg2, [sp, bytes_below_hard_fp]
+ stp reg3, reg4, [sp, bytes_below_hard_fp + 16] */
cfun->machine->frame.initial_adjust = cfun->machine->frame.frame_size;
cfun->machine->frame.callee_offset
= cfun->machine->frame.frame_size - cfun->machine->frame.hard_fp_offset;
@@ -4799,22 +4801,23 @@ aarch64_layout_frame (void)
else if (cfun->machine->frame.hard_fp_offset.is_constant (&const_fp_offset)
&& const_fp_offset < max_push_offset)
{
- /* Frame with large outgoing arguments but a small local area:
+ /* Frame with large area below the saved registers, but with a
+ small area above:
stp reg1, reg2, [sp, -hard_fp_offset]!
stp reg3, reg4, [sp, 16]
- sub sp, sp, outgoing_args_size */
+ sub sp, sp, bytes_below_hard_fp */
cfun->machine->frame.callee_adjust = const_fp_offset;
cfun->machine->frame.final_adjust
= cfun->machine->frame.frame_size - cfun->machine->frame.callee_adjust;
}
else
{
- /* Frame with large local area and outgoing arguments using frame pointer:
+ /* General case:
sub sp, sp, hard_fp_offset
stp x29, x30, [sp, 0]
add x29, sp, 0
stp reg3, reg4, [sp, 16]
- sub sp, sp, outgoing_args_size */
+ sub sp, sp, bytes_below_hard_fp */
cfun->machine->frame.initial_adjust = cfun->machine->frame.hard_fp_offset;
cfun->machine->frame.final_adjust
= cfun->machine->frame.frame_size - cfun->machine->frame.initial_adjust;
@@ -5243,9 +5246,11 @@ aarch64_get_separate_components (void)
if (aarch64_register_saved_on_entry (regno))
{
poly_int64 offset = cfun->machine->frame.reg_offset[regno];
+
+ /* Get the offset relative to the register we'll use. */
if (!frame_pointer_needed)
- offset += cfun->machine->frame.frame_size
- - cfun->machine->frame.hard_fp_offset;
+ offset += cfun->machine->frame.bytes_below_hard_fp;
+
/* Check that we can access the stack slot of the register with one
direct load with no adjustments needed. */
if (offset_12bit_unsigned_scaled_p (DImode, offset))
@@ -5367,8 +5372,8 @@ aarch64_process_components (sbitmap components, bool prologue_p)
rtx reg = gen_rtx_REG (mode, regno);
poly_int64 offset = cfun->machine->frame.reg_offset[regno];
if (!frame_pointer_needed)
- offset += cfun->machine->frame.frame_size
- - cfun->machine->frame.hard_fp_offset;
+ offset += cfun->machine->frame.bytes_below_hard_fp;
+
rtx addr = plus_constant (Pmode, ptr_reg, offset);
rtx mem = gen_frame_mem (mode, addr);
@@ -5410,8 +5415,7 @@ aarch64_process_components (sbitmap components, bool prologue_p)
/* REGNO2 can be saved/restored in a pair with REGNO. */
rtx reg2 = gen_rtx_REG (mode, regno2);
if (!frame_pointer_needed)
- offset2 += cfun->machine->frame.frame_size
- - cfun->machine->frame.hard_fp_offset;
+ offset2 += cfun->machine->frame.bytes_below_hard_fp;
rtx addr2 = plus_constant (Pmode, ptr_reg, offset2);
rtx mem2 = gen_frame_mem (mode, addr2);
rtx set2 = prologue_p ? gen_rtx_SET (mem2, reg2)
@@ -5478,10 +5482,10 @@ aarch64_stack_clash_protection_alloca_probe_range (void)
registers. If POLY_SIZE is not large enough to require a probe this function
will only adjust the stack. When allocating the stack space
FRAME_RELATED_P is then used to indicate if the allocation is frame related.
- FINAL_ADJUSTMENT_P indicates whether we are allocating the outgoing
- arguments. If we are then we ensure that any allocation larger than the ABI
- defined buffer needs a probe so that the invariant of having a 1KB buffer is
- maintained.
+ FINAL_ADJUSTMENT_P indicates whether we are allocating the area below
+ the saved registers. If we are then we ensure that any allocation
+ larger than the ABI defined buffer needs a probe so that the
+ invariant of having a 1KB buffer is maintained.
We emit barriers after each stack adjustment to prevent optimizations from
breaking the invariant that we never drop the stack more than a page. This
@@ -5671,7 +5675,7 @@ aarch64_allocate_and_probe_stack_space (rtx temp1, rtx temp2,
/* Handle any residuals. Residuals of at least MIN_PROBE_THRESHOLD have to
be probed. This maintains the requirement that each page is probed at
least once. For initial probing we probe only if the allocation is
- more than GUARD_SIZE - buffer, and for the outgoing arguments we probe
+ more than GUARD_SIZE - buffer, and below the saved registers we probe
if the amount is larger than buffer. GUARD_SIZE - buffer + buffer ==
GUARD_SIZE. This works that for any allocation that is large enough to
trigger a probe here, we'll have at least one, and if they're not large
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index af0bc3f18817..95831637ba73 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -712,9 +712,13 @@ struct GTY (()) aarch64_frame
HOST_WIDE_INT saved_varargs_size;
/* The size of the saved callee-save int/FP registers. */
-
HOST_WIDE_INT saved_regs_size;
+ /* The number of bytes between the bottom of the static frame (the bottom
+ of the outgoing arguments) and the hard frame pointer. This value is
+ always a multiple of STACK_BOUNDARY. */
+ poly_int64 bytes_below_hard_fp;
+
/* Offset from the base of the frame (incomming SP) to the
top of the locals area. This value is always a multiple of
STACK_BOUNDARY. */
--
2.42.0