Currently unaligned access functions are defined in tsan_interface.cpp
and do a real call to MemoryAccess. This means we have a real call
and no read/write constant propagation.
Unaligned memory access can be quite hot for some programs
(observed on some compression algorithms with ~90% of unaligned accesses).
Move them to tsan_interface_inl.h to avoid the additional call
and enable constant propagation.
Also reorder the actual store and memory access handling for
__sanitizer_unaligned_store callbacks to enable tail calling
in MemoryAccess.
Depends on D107282.
Reviewed By: vitalybuka, melver
Differential Revision: https://reviews.llvm.org/D107283
Currently we have MemoryAccess function that accepts
"bool kAccessIsWrite, bool kIsAtomic" and 4 wrappers:
MemoryRead/MemoryWrite/MemoryReadAtomic/MemoryWriteAtomic.
Such scheme with bool flags is not particularly scalable/extendable.
Because of that we did not have Read/Write wrappers for UnalignedMemoryAccess,
and "true, false" or "false, true" at call sites is not very readable.
Moreover, the new tsan runtime will introduce more flags
(e.g. move "freed" and "vptr access" to memory acccess flags).
We can't have 16 wrappers and each flag also takes whole
64-bit register for non-inlined calls.
Introduce AccessType enum that contains bit mask of
read/write, atomic/non-atomic, and later free/non-free,
vptr/non-vptr.
Such scheme is more scalable, more readble, more efficient
(don't consume multiple registers for these flags during calls)
and allows to cover unaligned and range variations of memory
access functions as well.
Also switch from size log to just size.
The new tsan runtime won't have the limitation of supporting
only 1/2/4/8 access sizes, so we don't need the logarithms.
Also add an inline thunk that converts the new interface to the old one.
For inlined calls it should not add any overhead because
all flags/size can be computed as compile time.
Reviewed By: vitalybuka, melver
Differential Revision: https://reviews.llvm.org/D107276
-mbranch-protection protects the LR on the stack with PAC.
When the frames are walked the LR need to be cleared.
This inline assembly later will be replaced with a new builtin.
Test: build with -DCMAKE_C_FLAGS="-mbranch-protection=standard".
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D98008
-mbranch-protection protects the LR on the stack with PAC.
When the frames are walked the LR need to be cleared.
This inline assembly later will be replaced with a new builtin.
Test: build with -DCMAKE_C_FLAGS="-mbranch-protection=standard".
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D98008
Dmitry Vyukov