Displaying 3 results from an estimated 3 matches for "copcost".
Did you mean:
copycost
2019 Jun 02
2
Optimizing Compare instruction selection
.../llvm-7.0.1.src/lib/CodeGen/MachineRegisterInfo.cpp, line 170.
If I remove the ‘isAllocatable=0’ setting on the SR register, then LLVM will try to spill the SR by calling ‘storeRegToStackSlot’, which then I stop with my own assertion because the SR can’t be spilled.
If I then remove also the ‘let CopCost = -1’ for the SR register, then LLVM attempts to move it to a general purpose register by calling ‘copyPhysRegs’, which again I stop with an assertion because it’s not legal in my architecture.
So, I’m stuck as well with this approach.
Any ideas, on what I can try?
I think, that at this point I...
2019 Jun 05
2
Optimizing Compare instruction selection
...deGen/MachineRegisterInfo.cpp, line 170.
>
> If I remove the ‘isAllocatable=0’ setting on the SR register, then LLVM will try to spill the SR by calling ‘storeRegToStackSlot’, which then I stop with my own assertion because the SR can’t be spilled.
>
> If I then remove also the ‘let CopCost = -1’ for the SR register, then LLVM attempts to move it to a general purpose register by calling ‘copyPhysRegs’, which again I stop with an assertion because it’s not legal in my architecture.
>
> So, I’m stuck as well with this approach.
>
> Any ideas, on what I can try?
>
&g...
2019 Jun 01
2
Optimizing Compare instruction selection
I attempt to optimize the use of the ‘CMP’ instruction on my architecture by removing the instruction instances where the Status Register already had the correct status flags.
The cmp instruction in my architecture is the typical one that compares two registers, or a register with an immediate, and sets the Status Flags accordingly. I implemented my ‘cmp’ instruction in LLVM by custom lowering