This virtual function will replace allocation_order_begin/end as the one
to override when implementing custom allocation orders. It is simpler to
have one function return an ArrayRef than having two virtual functions
computing different ends of the same array.
Use getRawAllocationOrder() in place of allocation_order_begin() where
it makes sense, but leave some clients that look like they really want
the filtered allocation orders from RegisterClassInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133170 91177308-0d34-0410-b5e6-96231b3b80d8
The order of registers returned by getCalleeSavedRegs is used to lay out
the fixed stack slots for CSRs. Some targets like their CSRs used from
one end, and some targets want them used from the other end.
When computing an allocation order, simply preserve the relative
ordering of CSRs that the target specifies in its allocation order.
Reordering CSRs would break some targets, ARM in particular.
We still place volatiles before the CSRs, providing slightly better
results with different calling conventions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132680 91177308-0d34-0410-b5e6-96231b3b80d8
Previously, these aliases would be ordered alphabetically. (BH, BL)
Print out the computed allocation orders.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132580 91177308-0d34-0410-b5e6-96231b3b80d8
I was confused whether new uint8_t[] would zero-initialize the returned
array, and it seems that so is gcc-4.0.
This should fix the test failures on darwin 9.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132500 91177308-0d34-0410-b5e6-96231b3b80d8
register classes.
It provides information for each register class that cannot be
determined statically, like:
- The number of allocatable registers in a class after filtering out the
reserved and invalid registers.
- The preferred allocation order with registers that overlap callee-saved
registers last.
- The last callee-saved register that overlaps a given physical register.
This information usually doesn't change between functions, so it is
reused for compiling multiple functions when possible. The many
possible combinations of reserved and callee saves registers makes it
unfeasible to compute this information statically in TableGen.
Use RegisterClassInfo to count available registers in various heuristics
in SimpleRegisterCoalescing, making the pass run 4% faster.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132450 91177308-0d34-0410-b5e6-96231b3b80d8
