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| author | Tamar Christina <tamar.christina@arm.com> | 2020-06-08 09:23:10 +0100 |
|---|---|---|
| committer | Tamar Christina <tamar.christina@arm.com> | 2020-06-08 09:23:10 +0100 |
| commit | d6430e3cccb37bec6c5604dffe48c52016509013 (patch) | |
| tree | 8e482564160f01253b3eb9070d54cb701c481453 /gcc | |
| parent | 635408da1eb1d441ef4d59fe00a038c920e51085 (diff) | |
| download | gcc-d6430e3cccb37bec6c5604dffe48c52016509013.zip gcc-d6430e3cccb37bec6c5604dffe48c52016509013.tar.gz gcc-d6430e3cccb37bec6c5604dffe48c52016509013.tar.bz2 | |
AArch64: Expand on comment of stack-clash and implicit probing through LR.
This expands the comment on an assert we have in aarch64_layout_frame
and points to an existing comment somewhere else that has a much longer
explanation of what's going on.
Committed under the GCC Obvious rule.
gcc/ChangeLog:
* config/aarch64/aarch64.c (aarch64_layout_frame): Expand comments.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/aarch64/aarch64.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index 97da607..973c65a 100644 --- a/gcc/config/aarch64/aarch64.c +++ b/gcc/config/aarch64/aarch64.c @@ -6531,7 +6531,9 @@ aarch64_layout_frame (void) && !crtl->abi->clobbers_full_reg_p (regno)) frame.reg_offset[regno] = SLOT_REQUIRED; - /* With stack-clash, LR must be saved in non-leaf functions. */ + /* With stack-clash, LR must be saved in non-leaf functions. The saving of + LR counts as an implicit probe which allows us to maintain the invariant + described in the comment at expand_prologue. */ gcc_assert (crtl->is_leaf || maybe_ne (frame.reg_offset[R30_REGNUM], SLOT_NOT_REQUIRED)); |