AArch64 has five system registers intended to be useful as thread
pointers: one for each exception level which is RW at that level and
inaccessible to lower ones, and the special TPIDRRO_EL0 which is
readable but not writable at EL0. AArch32 has three, corresponding to
the AArch64 ones that aren't specific to EL2 or EL3.
Currently clang supports only a subset of these registers, and not
even a consistent subset between AArch64 and AArch32:
- For AArch64, clang permits you to choose between the four TPIDR_ELn
thread registers, but not the fifth one, TPIDRRO_EL0.
- In AArch32, on the other hand, the //only// thread register you can
choose (apart from 'none, use a function call') is TPIDRURO, which
corresponds to (the bottom 32 bits of) AArch64's TPIDRRO_EL0.
So there is no thread register that you can currently use in both
targets!
For custom and bare-metal purposes, users might very reasonably want
to use any of these thread registers. There's no reason they shouldn't
all be supported as options, even if the default choices follow
existing practice on typical operating systems.
This commit extends the range of values acceptable to the `-mtp=`
clang option, so that you can specify any of these registers by (the
lower-case version of) their official names in the ArmARM:
- For AArch64: tpidr_el0, tpidrro_el0, tpidr_el1, tpidr_el2, tpidr_el3
- For AArch32: tpidrurw, tpidruro, tpidrprw
All existing values of the option are still supported and behave the
same as before. Defaults are also unchanged. No command line that
worked already should change behaviour as a result of this.
The new values for the `-mtp=` option have been agreed with Arm's gcc
developers (although I don't know whether they plan to implement them
in the near future).
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D152433
In ARM mode, passing -mtp=cp15 forces the use of an inline MRC system register read to move the thread pointer value into a register.
Currently, in Thumb2 mode, -mtp=cp15 is ignored, and a call to the __aeabi_read_tp helper is emitted instead.
This is inconsistent, and breaks the Linux/ARM build for Thumb2 targets, as the Linux kernel does not provide an implementation of __aeabi_read_tp,.
Reviewed By: nickdesaulniers, peter.smith
Differential Revision: https://reviews.llvm.org/D112600
Replace the use of grep with FileCheck. Tidy up some of the tests. A
few of the tests have been left as weak as previously, though some have
been made more stringent.
llvm-svn: 290616
Both AArch64 and ARM support llvm.<arch>.thread.pointer intrinsics that
just return the thread pointer. I have a pending patch that does the same
for SystemZ (D19054), and there are many more targets that could benefit
from one.
This patch merges the ARM and AArch64 intrinsics into a single target
independent one that will also be used by subsequent targets.
Differential Revision: http://reviews.llvm.org/D19098
llvm-svn: 266818
This was done through the aid of a terrible Perl creation. I will not
paste any of the horrors here. Suffice to say, it require multiple
staged rounds of replacements, state carried between, and a few
nested-construct-parsing hacks that I'm not proud of. It happens, by
luck, to be able to deal with all the TCL-quoting patterns in evidence
in the LLVM test suite.
If anyone is maintaining large out-of-tree test trees, feel free to poke
me and I'll send you the steps I used to convert things, as well as
answer any painful questions etc. IRC works best for this type of thing
I find.
Once converted, switch the LLVM lit config to use ShTests the same as
Clang. In addition to being able to delete large amounts of Python code
from 'lit', this will also simplify the entire test suite and some of
lit's architecture.
Finally, the test suite runs 33% faster on Linux now. ;]
For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s
llvm-svn: 159525
