Displaying 3 results from an estimated 3 matches for "i32regclass".
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32regclass
2013 Jun 24
1
[LLVMdev] Register Class assignment for integer and pointer types
...give (load reg, iPTR:$addr) to match pattern.
1.4 and finally we "hope" default register allocator do the proper thing.
2. add an annotation pass before register allocation.
2.1 we treat both integer and pointer as i32, and hence there is just
"addRegisterClass(MVT::i32, XXX::I32RegClass);"
2.2 before register allocation we annote operands if they must reside in
address register.
2.3 register allocation assigns register class according to annotations
mentioned in 2.2, and perhaps a custom register allocator has to be
implemented.
Which way do you think is more feasible?
Re...
2013 Jun 23
0
[LLVMdev] Register Class assignment for integer and pointer types
Hi,
In our version of LLVM, we've added different-sized iPTR* types, so we have an iPTR256 for our fat pointers. This causes some problems with constraints, because the way that TableGen resolves constraints is not expected to handle multiple pointer types. We've added a flag that can be set on a per-backend basis to turn this off.
Our problem is perhaps a bit different form yours,
2013 Jun 23
3
[LLVMdev] Register Class assignment for integer and pointer types
David, thanks for your immediate response.
Since iPTR is a reserved type for tablegen internal use, can you make a
further explanation?
On the other hand, it can be simply treated as a register class assignment
problem during register allocation.
Assume both pointer and integet have a 32 bit width. backend handles it
just as to i32. When it performs register allocation, it can retrieve from