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authorRichard Sandiford <richard.sandiford@arm.com>2023-09-12 16:05:05 +0100
committerRichard Sandiford <richard.sandiford@arm.com>2023-09-12 16:05:05 +0100
commitc601c918c9ac01ef8315774a642ff924f77c85e5 (patch)
tree792c097cf6535c514c29af4ecb630a11315c9df3
parentf9ab771fa8cd747f34786c6f33deea32c2eb828b (diff)
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aarch64: Explicitly handle frames with no saved registers
If a frame has no saved registers, it can be allocated in one go. There is no need to treat the areas below and above the saved registers as separate. And if we allocate the frame in one go, it should be allocated as the initial_adjust rather than the final_adjust. This allows the frame size to grow to guard_size - guard_used_by_caller before a stack probe is needed. (A frame with no register saves is necessarily a leaf frame.) This is a no-op as thing stand, since a leaf function will have no outgoing arguments, and so all the frame will be above where the saved registers normally go. gcc/ * config/aarch64/aarch64.cc (aarch64_layout_frame): Explicitly allocate the frame in one go if there are no saved registers.
-rw-r--r--gcc/config/aarch64/aarch64.cc8
1 files changed, 5 insertions, 3 deletions
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 9fb9462..34d0ccc 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -8678,9 +8678,11 @@ aarch64_layout_frame (void)
HOST_WIDE_INT const_size, const_outgoing_args_size, const_fp_offset;
HOST_WIDE_INT const_saved_regs_size;
- if (frame.frame_size.is_constant (&const_size)
- && const_size < max_push_offset
- && known_eq (frame.hard_fp_offset, const_size))
+ if (known_eq (frame.saved_regs_size, 0))
+ frame.initial_adjust = frame.frame_size;
+ else if (frame.frame_size.is_constant (&const_size)
+ && const_size < max_push_offset
+ && known_eq (frame.hard_fp_offset, const_size))
{
/* Simple, small frame with no outgoing arguments: