return STACK_SLOT_ALIGNMENT (type, mode, alignment);
}
+/* Determine whether it is possible to fit a stack slot of size SIZE and
+ alignment ALIGNMENT into an area in the stack frame that starts at
+ frame offset START and has a length of LENGTH. If so, store the frame
+ offset to be used for the stack slot in *POFFSET and return true;
+ return false otherwise. This function will extend the frame size when
+ given a start/length pair that lies at the end of the frame. */
+
+static bool
+try_fit_stack_local (HOST_WIDE_INT start, HOST_WIDE_INT length,
+ HOST_WIDE_INT size, unsigned int alignment,
+ HOST_WIDE_INT *poffset)
+{
+ HOST_WIDE_INT this_frame_offset;
+ int frame_off, frame_alignment, frame_phase;
+
+ /* Calculate how many bytes the start of local variables is off from
+ stack alignment. */
+ frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
+ frame_off = STARTING_FRAME_OFFSET % frame_alignment;
+ frame_phase = frame_off ? frame_alignment - frame_off : 0;
+
+ /* Round the frame offset to the specified alignment. */
+
+ /* We must be careful here, since FRAME_OFFSET might be negative and
+ division with a negative dividend isn't as well defined as we might
+ like. So we instead assume that ALIGNMENT is a power of two and
+ use logical operations which are unambiguous. */
+ if (FRAME_GROWS_DOWNWARD)
+ this_frame_offset
+ = (FLOOR_ROUND (start + length - size - frame_phase,
+ (unsigned HOST_WIDE_INT) alignment)
+ + frame_phase);
+ else
+ this_frame_offset
+ = (CEIL_ROUND (start - frame_phase,
+ (unsigned HOST_WIDE_INT) alignment)
+ + frame_phase);
+
+ /* See if it fits. If this space is at the edge of the frame,
+ consider extending the frame to make it fit. Our caller relies on
+ this when allocating a new slot. */
+ if (frame_offset == start && this_frame_offset < frame_offset)
+ frame_offset = this_frame_offset;
+ else if (this_frame_offset < start)
+ return false;
+ else if (start + length == frame_offset
+ && this_frame_offset + size > start + length)
+ frame_offset = this_frame_offset + size;
+ else if (this_frame_offset + size > start + length)
+ return false;
+
+ *poffset = this_frame_offset;
+ return true;
+}
+
+/* Create a new frame_space structure describing free space in the stack
+ frame beginning at START and ending at END, and chain it into the
+ function's frame_space_list. */
+
+static void
+add_frame_space (HOST_WIDE_INT start, HOST_WIDE_INT end)
+{
+ struct frame_space *space = GGC_NEW (struct frame_space);
+ space->next = crtl->frame_space_list;
+ crtl->frame_space_list = space;
+ space->start = start;
+ space->length = end - start;
+}
+
/* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
with machine mode MODE.
{
rtx x, addr;
int bigend_correction = 0;
+ HOST_WIDE_INT slot_offset, old_frame_offset;
unsigned int alignment, alignment_in_bits;
- int frame_off, frame_alignment, frame_phase;
if (align == 0)
{
alignment_in_bits = alignment * BITS_PER_UNIT;
- if (FRAME_GROWS_DOWNWARD)
- frame_offset -= size;
-
/* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
{
if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
crtl->max_used_stack_slot_alignment = alignment_in_bits;
- /* Calculate how many bytes the start of local variables is off from
- stack alignment. */
- frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
- frame_off = STARTING_FRAME_OFFSET % frame_alignment;
- frame_phase = frame_off ? frame_alignment - frame_off : 0;
+ if (mode != BLKmode || size != 0)
+ {
+ struct frame_space **psp;
- /* Round the frame offset to the specified alignment. The default is
- to always honor requests to align the stack but a port may choose to
- do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
- if (STACK_ALIGNMENT_NEEDED
- || mode != BLKmode
- || size != 0)
+ for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
+ {
+ struct frame_space *space = *psp;
+ if (!try_fit_stack_local (space->start, space->length, size,
+ alignment, &slot_offset))
+ continue;
+ *psp = space->next;
+ if (slot_offset > space->start)
+ add_frame_space (space->start, slot_offset);
+ if (slot_offset + size < space->start + space->length)
+ add_frame_space (slot_offset + size,
+ space->start + space->length);
+ goto found_space;
+ }
+ }
+ else if (!STACK_ALIGNMENT_NEEDED)
{
- /* We must be careful here, since FRAME_OFFSET might be negative and
- division with a negative dividend isn't as well defined as we might
- like. So we instead assume that ALIGNMENT is a power of two and
- use logical operations which are unambiguous. */
- if (FRAME_GROWS_DOWNWARD)
- frame_offset
- = (FLOOR_ROUND (frame_offset - frame_phase,
- (unsigned HOST_WIDE_INT) alignment)
- + frame_phase);
- else
- frame_offset
- = (CEIL_ROUND (frame_offset - frame_phase,
- (unsigned HOST_WIDE_INT) alignment)
- + frame_phase);
+ slot_offset = frame_offset;
+ goto found_space;
}
+ old_frame_offset = frame_offset;
+
+ if (FRAME_GROWS_DOWNWARD)
+ {
+ frame_offset -= size;
+ try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
+
+ if (slot_offset > frame_offset)
+ add_frame_space (frame_offset, slot_offset);
+ if (slot_offset + size < old_frame_offset)
+ add_frame_space (slot_offset + size, old_frame_offset);
+ }
+ else
+ {
+ frame_offset += size;
+ try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
+
+ if (slot_offset > old_frame_offset)
+ add_frame_space (old_frame_offset, slot_offset);
+ if (slot_offset + size < frame_offset)
+ add_frame_space (slot_offset + size, frame_offset);
+ }
+
+ found_space:
/* On a big-endian machine, if we are allocating more space than we will use,
use the least significant bytes of those that are allocated. */
if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
if (virtuals_instantiated)
addr = plus_constant (frame_pointer_rtx,
trunc_int_for_mode
- (frame_offset + bigend_correction
+ (slot_offset + bigend_correction
+ STARTING_FRAME_OFFSET, Pmode));
else
addr = plus_constant (virtual_stack_vars_rtx,
trunc_int_for_mode
- (frame_offset + bigend_correction,
+ (slot_offset + bigend_correction,
Pmode));
- if (!FRAME_GROWS_DOWNWARD)
- frame_offset += size;
-
x = gen_rtx_MEM (mode, addr);
set_mem_align (x, alignment_in_bits);
MEM_NOTRAP_P (x) = 1;
static void
assign_parms_initialize_all (struct assign_parm_data_all *all)
{
- tree fntype;
+ tree fntype ATTRIBUTE_UNUSED;
memset (all, 0, sizeof (*all));
cfun = GGC_CNEW (struct function);
- cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
-
init_eh_for_function ();
if (init_machine_status)
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