llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-26 06:29:20 +00:00

History

Duncan Sands 667d4b8de6 Introduce new linkage types linkonce_odr, weak_odr, common_odr and extern_weak_odr. These are the same as the non-odr versions, except that they indicate that the global will only be overridden by an equivalent global. In C, a function with weak linkage can be overridden by a function which behaves completely differently. This means that IP passes have to skip weak functions, since any deductions made from the function definition might be wrong, since the definition could be replaced by something completely different at link time. This is not allowed in C++, thanks to the ODR (One-Definition-Rule): if a function is replaced by another at link-time, then the new function must be the same as the original function. If a language knows that a function or other global can only be overridden by an equivalent global, it can give it the weak_odr linkage type, and the optimizers will understand that it is alright to make deductions based on the function body. The code generators on the other hand map weak and weak_odr linkage to the same thing. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66339 91177308-0d34-0410-b5e6-96231b3b80d8		2009-03-07 15:45:40 +00:00
..
AsmPrinter	Introduce new linkage types linkonce_odr, weak_odr, common_odr	2009-03-07 15:45:40 +00:00
Alpha.h	Overhaul my earlier submission due to feedback. It's a large patch, but most of	2009-02-24 08:30:20 +00:00
Alpha.td
AlphaBranchSelector.cpp
AlphaCodeEmitter.cpp
AlphaInstrFormats.td
AlphaInstrInfo.cpp	Factor out the code to add a MachineOperand to a MachineInstrBuilder.	2009-02-18 05:45:50 +00:00
AlphaInstrInfo.h	Turns out AnalyzeBranch can modify the mbb being analyzed. This is a nasty	2009-02-09 07:14:22 +00:00
AlphaInstrInfo.td
AlphaISelDAGToDAG.cpp	Remove non-DebugLoc forms of CopyToReg and CopyFromReg.	2009-02-04 23:02:30 +00:00
AlphaISelLowering.cpp	Remove non-DebugLoc versions of BuildMI from Alpha and Cell.	2009-02-13 02:30:42 +00:00
AlphaISelLowering.h	Constify TargetInstrInfo::EmitInstrWithCustomInserter, allowing	2009-02-07 16:15:20 +00:00
AlphaJITInfo.cpp
AlphaJITInfo.h
AlphaLLRP.cpp	Remove non-DebugLoc versions of BuildMI from Alpha and Cell.	2009-02-13 02:30:42 +00:00
AlphaRegisterInfo.cpp	Propagate debug loc info through prologue/epilogue.	2009-02-23 00:42:30 +00:00
AlphaRegisterInfo.h
AlphaRegisterInfo.td
AlphaRelocations.h
AlphaSchedule.td
AlphaSubtarget.cpp
AlphaSubtarget.h
AlphaTargetAsmInfo.cpp
AlphaTargetAsmInfo.h
AlphaTargetMachine.cpp	Overhaul my earlier submission due to feedback. It's a large patch, but most of	2009-02-24 08:30:20 +00:00
AlphaTargetMachine.h
CMakeLists.txt
Makefile	Removed trailing whitespace from Makefiles.	2009-01-09 16:44:42 +00:00
README.txt

README.txt

***

add gcc builtins for alpha instructions


***

custom expand byteswap into nifty 
extract/insert/mask byte/word/longword/quadword low/high
sequences

***

see if any of the extract/insert/mask operations can be added

***

match more interesting things for cmovlbc cmovlbs (move if low bit clear/set)

***

lower srem and urem

remq(i,j):  i - (j * divq(i,j)) if j != 0
remqu(i,j): i - (j * divqu(i,j)) if j != 0
reml(i,j):  i - (j * divl(i,j)) if j != 0
remlu(i,j): i - (j * divlu(i,j)) if j != 0

***

add crazy vector instructions (MVI):

(MIN|MAX)(U|S)(B8|W4) min and max, signed and unsigned, byte and word
PKWB, UNPKBW pack/unpack word to byte
PKLB UNPKBL pack/unpack long to byte
PERR pixel error (sum accross bytes of bytewise abs(i8v8 a - i8v8 b))

cmpbytes bytewise cmpeq of i8v8 a and i8v8 b (not part of MVI extentions)

this has some good examples for other operations that can be synthesised well 
from these rather meager vector ops (such as saturating add).
http://www.alphalinux.org/docs/MVI-full.html