llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-09-08 23:55:03 +00:00

History

Andrew Lenharth c8aba85e1c I am sure I had commited this workaround before. Perhaps soon I should sort it all out git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28772 91177308-0d34-0410-b5e6-96231b3b80d8		2006-06-13 20:34:47 +00:00
..
.cvsignore
Alpha.h
Alpha.td
AlphaAsmPrinter.cpp
AlphaCodeEmitter.cpp
AlphaInstrFormats.td
AlphaInstrInfo.cpp
AlphaInstrInfo.h
AlphaInstrInfo.td
AlphaISelDAGToDAG.cpp	I am sure I had commited this workaround before. Perhaps soon I should sort it all out	2006-06-13 20:34:47 +00:00
AlphaISelLowering.cpp	It really helps to be returning to the correct place	2006-06-13 18:27:39 +00:00
AlphaISelLowering.h	It really helps to be returning to the correct place	2006-06-13 18:27:39 +00:00
AlphaJITInfo.cpp
AlphaJITInfo.h
AlphaRegisterInfo.cpp
AlphaRegisterInfo.h
AlphaRegisterInfo.td
AlphaRelocations.h
AlphaSchedule.td
AlphaSubtarget.cpp
AlphaSubtarget.h
AlphaTargetMachine.cpp
AlphaTargetMachine.h
Makefile
README.txt

README.txt

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Fix Ordered/Unordered FP stuff


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
improve bytezap opertunities
ulong %foo(ulong %y) {
entry:
        %tmp = and ulong %y,  65535
        %tmp2 = shr ulong %tmp,  ubyte 3
        ret ulong %tmp2
}


compiles to a 3 instruction sequence without instcombine
        zapnot $16,3,$0
        srl $0,3,$0
        ret $31,($26),1
 
After instcombine you get
ulong %foo(ulong %y) {
entry:
        %tmp = shr ulong %y, ubyte 3            ; <ulong> [#uses=1]
        %tmp2 = and ulong %tmp, 8191            ; <ulong> [#uses=1]
        ret ulong %tmp2
}

which compiles to
        lda $0,8191($31)
        srl $16,3,$1
        and $1,$0,$0
        ret $31,($26),1