Mercurial > lcfOS
annotate python/target/armframe.py @ 299:674789d9ff37
Added a doc
| author | Windel Bouwman |
|---|---|
| date | Sun, 01 Dec 2013 18:37:23 +0100 |
| parents | 534b94b40aa8 |
| children | 158068af716c |
| rev | line source |
|---|---|
| 211 | 1 import ir |
| 290 | 2 from .basetarget import Label, Comment, Alignment, LabelRef, DebugInfo, Nop |
| 292 | 3 from .basetarget import Imm7 |
| 4 from irmach import AbstractInstruction as makeIns, Frame | |
| 5 from .arminstructions import Dcd, AddSp, SubSp, Push, Pop, Mov2 | |
| 6 from .arminstructions import R0, R1, R2, R3, R4, R5, R6, R7, LR, PC, SP | |
| 274 | 7 |
| 290 | 8 |
| 292 | 9 class ArmFrame(Frame): |
| 10 """ Arm specific frame for functions. """ | |
| 275 | 11 def __init__(self, name): |
| 12 # We use r7 as frame pointer. | |
| 13 super().__init__(name) | |
| 292 | 14 self.regs = [R0, R1, R2, R3, R4, R5, R6] |
| 275 | 15 self.rv = ir.Temp('special_RV') |
| 16 self.p1 = ir.Temp('special_P1') | |
| 17 self.p2 = ir.Temp('special_P2') | |
| 18 self.p3 = ir.Temp('special_P3') | |
| 19 self.p4 = ir.Temp('special_P4') | |
| 20 self.fp = ir.Temp('special_FP') | |
| 21 # Pre-colored registers: | |
| 22 self.tempMap = {} | |
| 292 | 23 self.tempMap[self.rv] = R0 |
| 24 self.tempMap[self.p1] = R1 | |
| 25 self.tempMap[self.p2] = R2 | |
| 26 self.tempMap[self.p3] = R3 | |
| 27 self.tempMap[self.p4] = R4 | |
| 28 self.tempMap[self.fp] = R7 | |
| 275 | 29 self.locVars = {} |
| 30 self.parMap = {} | |
| 276 | 31 # Literal pool: |
| 32 self.constants = [] | |
| 275 | 33 |
| 34 def argLoc(self, pos): | |
| 35 """ | |
| 36 Gets the function parameter location in IR-code format. | |
| 37 """ | |
| 38 if pos == 0: | |
| 39 return self.p1 | |
| 40 elif pos == 1: | |
| 41 return self.p2 | |
| 42 elif pos == 2: | |
| 43 return self.p3 | |
| 44 elif pos == 3: | |
| 45 return self.p4 | |
| 46 else: | |
| 47 raise NotImplementedError('No more than 4 parameters implemented') | |
| 48 | |
| 49 def allocVar(self, lvar): | |
| 50 if lvar not in self.locVars: | |
| 51 self.locVars[lvar] = self.stacksize | |
| 52 self.stacksize = self.stacksize + 4 | |
| 53 return self.locVars[lvar] | |
| 54 | |
| 276 | 55 def addConstant(self, value): |
| 56 lab_name = '{}_literal_{}'.format(self.name, len(self.constants)) | |
| 57 self.constants.append((lab_name, value)) | |
| 58 return lab_name | |
| 59 | |
| 275 | 60 def EntryExitGlue3(self): |
| 61 """ | |
| 62 Add code for the prologue and the epilogue. Add a label, the | |
| 63 return instruction and the stack pointer adjustment for the frame. | |
| 64 """ | |
| 292 | 65 self.instructions.insert(0, makeIns(Label(self.name))) |
| 66 self.instructions.insert(1, makeIns(Push({LR, R7}))) | |
| 279 | 67 # Reserve stack space for locals: |
| 292 | 68 self.instructions.insert(2, makeIns(SubSp(SP, SP, Imm7(self.stacksize)))) |
| 279 | 69 # Setup frame pointer: |
| 292 | 70 self.instructions.insert(3, makeIns(Mov2(R7, SP))) |
| 279 | 71 # Stack grows downwards |
| 292 | 72 self.instructions.append(makeIns(AddSp(SP, SP, Imm7(self.stacksize)))) |
| 73 self.instructions.append(makeIns(Pop({PC, R7}))) | |
| 276 | 74 # Add constant literals: |
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Rework from str interface to Instruction interface
Windel Bouwman
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75 self.instructions.append(makeIns(Alignment(4))) # Align at 4 bytes |
| 276 | 76 for ln, v in self.constants: |
| 292 | 77 self.instructions.append(makeIns(Label(ln))) |
| 78 self.instructions.append(makeIns(Dcd(v))) |