loganleland / llvm Goto Github PK

Currently each stack frame has a size of at least 4 (parent FP, current FP, 2 regs for data) by default. There are two ways to tighten the size of each stack frame:

(1 Also there doesn't need to be a register for current FP. The FP reg (0x31) can point to where the parent FP is stored on each stack frame and use that to calculate the offsets for memory.

(2 Make the default SP calculation not include two reg's for local data by default

The code for ADDLW and SUBLW looks as follows currently:

def ADDLW  : I8rr<0x0,
                   (outs), (ins GR8:$src),
                   "addlw\t{$src}",
                   []>;

def SUBLW  : I8rr<0x0,
                   (outs), (ins GR8:$src),
                   "sublw\t{$src}",
                   []>;

The problems here are:

• No DAG pattern, so there is no matching. These instructions must be lowered manually.
• The W Register isn't implemented, so there are no DAG node... anchors? edges? I'm not too sure how LLVM refers to it. Regardless, these nodes have 1 input and 0 outputs.
• They inherit from I8rr instead of I8ri. Attempting to change it myself results in compilation errors, so @loganleland will need to fix it, since he knows what he changed to put it in.

I'll also point out that "SUBWF" and "SUBLW" are "Subtract W from the incoming data," so it looks like W = L - W and d = F - W. W should be $src2

This assertion fails when compiling C -> ASM via Clang. Compiling C -> IR -> ASM via Clang + LLD does not produce this error. I have not applied the ASM correction script.

This error only happened when compiling addrr.c and andrr.c, so I suppose it has to do with register-register transfers specifically.

Attaching log
addrr-a8a8be.txt

When compiling currently we have an unused variable. It seems prologue and epilogue don't use Instruction Info. NOPE not that function.

/home/developer/Projects/llvm-nope/llvm/lib/Target/PIC16/PIC16FrameLowering.cpp:214:26: warning: unused variable 'TII' [-Wunused-variable]
  const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
                         ^
/home/developer/Projects/llvm-nope/llvm/lib/Target/PIC16/PIC16FrameLowering.cpp:233:26: warning: unused variable 'TII' [-Wunused-variable]
  const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();