Oliver Stannard 0c0f765cab [ARM] Fix llvm.returnaddress for Thumb1 with R11 frame-pointer (#117735) ...

When the llvm.returnaddress intrinsic is used, the LR is marked as
live-in to the function, so it must be preserved through the prologue.
This is normally fine, but there is one case for Thumb1 where we use LR
as a temporary in the prologue to set up a frame chain using r11 as the
frame pointer. There are no other registers guaranteed to be free to do
this, so we have to re-load LR from the stack after pushing the callee
saved registers.

2024-11-28 09:37:57 +00:00

89 KiB

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