It turns that the issue was unrelated to the code-changes, but only triggered
by one of the tests. The SMEABI pass incorrectly marked the CFG as preserved,
even though it modified the CFG.
This reverts commit 8bcf5df3043a906c7124b70b59eda925eddd7319.
Changing the way the attribute is created changes the way the attribute
is added. Now it seems to be correctly added as a function attribute, whereas
before it was not. This led ISel ignoring attributes and setting up a lazy-save
buffer for the call to __arm_tpidr2_save.
This patch also marks the intrinsic call as 'preserves_za' which together with the
above prevents the code-generator from setting up a lazy-save buffer.
Reviewed By: kmclaughlin
Differential Revision: https://reviews.llvm.org/D136342
The new pass implements the following:
* Inserts code at the start of an arm_new_za function to
commit a lazy-save when the lazy-save mechanism is active.
* Adds a smstart intrinsic at the start of the function.
* Adds a smstop intrinsic at the end of the function.
Patch co-authored by kmclaughlin.
Differential Revision: https://reviews.llvm.org/D133896
