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comparison python/ppci/frontends/ks/irgenerator.py @ 103:28a35161ef23

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Added forgotten ir generator
author windel
date Wed, 26 Dec 2012 10:53:33 +0100
parents
children ed230e947dc6
comparison
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102:63937c8d1478 103:28a35161ef23
1 """
2 Generates ir code from ast tree.
3 """
4
5 from .nodes import *
6 from ...core.errors import Error
7 from ... import core
8 from .builtin import real, integer, boolean, char
9 #from .assembler import *
10
11 class KsIrGenerator:
12 def __init__(self):
13 pass
14
15 # Code generation functions:
16 def genexprcode(self, node):
17 """
18 Generate code for expressions!
19 Recursively evaluates, and ensures a register contains the answer.
20 register is an integer register or a floating point reg
21 """
22 if isinstance(node, Binop):
23 """ Handle a binary operation (two arguments) of some kind """
24 self.genexprcode(node.a)
25 self.genexprcode(node.b)
26
27 if node.op == 'mod':
28 assert(node.typ.isType(integer))
29 self.addCode(mov('rax', node.a.reg))
30 elif node.op == 'div':
31 assert(node.typ.isType(integer))
32 self.addCode(mov('rax', node.a.reg))
33 elif node.op == '*':
34 if node.typ.isType(integer):
35 self.addCode(imulreg64(node.a.reg, node.b.reg))
36 elif node.op == '+':
37 if node.typ.isType(integer):
38 self.addCode(addreg64(node.a.reg, node.b.reg))
39 elif node.op == '-':
40 if node.typ.isType(integer):
41 self.addCode(subreg64(node.a.reg, node.b.reg))
42 else:
43 Error('Unknown Binop {0}'.format(node.op))
44
45 elif type(node) is Unop:
46 if node.op == 'INTTOREAL':
47 self.genexprcode(node.a)
48 node.reg = node.a.reg
49 # TODO use 'FILD' instruction
50 freg = 12
51 code.append('Unop inttoreal TODO')
52 elif node.op == 'ABS':
53 if isType(node.typ, real):
54 code = [0xD9, 0xE1] # st(0) = fabs st(0)
55 Error('ABS error integer')
56 elif isType(node.typ, integer):
57 code = []
58 Error('ABS error integer')
59 else:
60 Error('ABS error')
61 else:
62 Error('Unknown Unop {0}'.format(node.op))
63
64 elif isinstance(node, Designator):
65 # dereference, array index. Make sure that the result comes into a register
66 if len(node.selectors) > 0:
67 self.gencode(node) # Load the pointer into some register
68
69 # Now we can access the object at location '[node.reg]':
70 if node.typ.isType(integer):
71 self.addCode( mov(node.reg, [node.reg, 0x0]) )
72 else:
73 Error('Only integer types implemented')
74 else:
75 # No selectors, load variable directly
76 if node.obj.typ.isType(integer):
77 if type(node.obj) is Constant:
78 self.genexprcode(node.obj)
79 node.reg = node.obj.reg
80 else:
81 self.getreg(node)
82 # Get a register to store the integer value
83 if node.obj.isLocal:
84 # relative to rbp:
85 self.addCode( mov(node.reg, ['rbp', node.obj.offset]) )
86 else:
87 self.addCode(mov(node.reg, ['RIP', 0x0]))
88 self.fixCode(self.rip-4, imm32(node.obj.offset - self.rip))
89 else:
90 Error('Cannot load variable type {0}'.format(node.typ))
91
92 elif isinstance(node, Relop):
93 # Create a boolean from operands
94 # TODO create an alternative for expressions used as conditions.
95 self.genexprcode(node.a)
96 self.genexprcode(node.b)
97
98 if node.a.typ.isType(integer):
99 self.freereg(node.b)
100 else:
101 Error('Relop not implemented for {0}'.format(node.a.typ))
102
103 elif type(node) is Constant:
104 if node.typ.isType(integer):
105 self.getreg(node)
106
107 elif type(node) is ProcedureCall:
108 if type(node.proc.obj) is BuiltinProcedure:
109 # Handle builtin procedures different, these not always call
110 # a function, but generate code.
111 bi = node.proc.obj
112 if bi.name == 'chr':
113 arg = node.args[0]
114 self.genexprcode(arg)
115 # Store character in full width register:
116 # TODO: store in char only register
117 node.reg = arg.reg
118 else:
119 Error('Unknown builtin function {0}'.format(bi.name))
120 else:
121 # Use generic procedure call first
122 self.gencode(node)
123 # Retrieve result:
124 if node.typ.isType(integer):
125 # Store result!
126 self.getreg(node)
127 self.addCode( mov(node.reg, 'rax') )
128 else:
129 Error('Return type not supported {0}'.format(node.typ))
130 else:
131 Error('Cannot generate expression code for: {0}'.format(node))
132
133 def gencode(self, node):
134 """ Code generation function for AST nodes """
135 if isinstance(node, Module):
136 # TODO: recurse!
137 return core.Module()
138
139 elif type(node) is Procedure:
140 # calculate offsets for local variables and parameters
141 # Variable location relative to 'rbp' register
142 variables = node.symtable.getAllLocal(Variable)
143 offset = 0
144 paramoffset = 16
145 for var in variables:
146 var.isLocal = True
147 if not var.isParameter:
148 offset += var.typ.size
149 # Offset is negative of rbp in stack frame
150 var.offset = -offset
151 node.framesize = offset
152 # Calculate offsets of parameters relative to rbp register
153 for par in reversed(node.typ.parameters):
154 pvar = node.symtable.getLocal(Variable, par.name)
155 pvar.offset = paramoffset
156 paramoffset += pvar.typ.size
157
158 # code generation
159 node.entrypoint = self.rip
160 self.addCode(push('rbp'))
161 self.addCode(mov('rbp', 'rsp')) # Setup the base pointer
162 self.addCode(subreg64('rsp', node.framesize)) # reserve space for locals
163 self.gencode(node.block)
164 if node.retexpr:
165 if node.retexpr.typ.isType(integer):
166 self.genexprcode(node.retexpr)
167 self.addCode( mov('rax', node.retexpr.reg) )
168 self.freereg(node.retexpr)
169 else:
170 Error('Cannot return this kind yet {0}'.format(node.retexpr.typ))
171 self.addCode( addreg64('rsp', node.framesize) )
172 self.addCode( pop('rbp') )
173 self.addCode( ret() )
174 assert(len(self.usedregs) == 0)
175
176 elif isinstance(node, StatementSequence):
177 for s in node.statements:
178 self.gencode(s)
179
180 elif type(node) is ProcedureCall:
181 # Prepare parameters on the stack:
182 stacksize = 0
183 assert(len(node.args) == len(node.proc.typ.parameters))
184 for arg, param in zip(node.args, node.proc.typ.parameters):
185
186 if param.kind == 'value':
187 self.genexprcode(arg)
188 self.addCode( push(arg.reg) )
189 self.freereg( arg )
190 stacksize += 8
191 else:
192 Error('Parameter kind other than value')
193
194 # Calculate address using designator
195 if type(node.proc.obj) is Procedure:
196 self.addCode( call(0x0) )
197 self.fixCode( self.rip - 4, imm32(node.proc.obj.entrypoint - self.rip))
198 elif type(node.proc.obj) is ImportedSymbol:
199 # Load the entry point of the import table
200 self.getreg(node.proc.obj)
201 # Load the address of the procedure:
202 self.addCode( mov(node.proc.obj.reg, ['RIP', 0x0]) )
203 self.fixCode( self.rip - 4, imm32(node.proc.obj.offset - self.rip) )
204 # Call to the address in register:
205 self.addCode( call(node.proc.obj.reg) )
206 # Free register that holds the address of the object
207 self.freereg( node.proc.obj )
208 elif type(node.proc.obj) is BuiltinProcedure:
209 if node.proc.obj.name == 'chr':
210 print('int to char')
211 else:
212 Error('Unknown builtin function {0}'.format(node.proc.obj.name))
213 else:
214 Error('Cannot call designator of type {0}'.format(node.proc.obj))
215
216 # Restore stack (pop all arguments of):
217 self.addCode(addreg64('rsp', stacksize))
218
219 elif type(node) is Assignment:
220 if node.lval.typ.isType(integer):
221 # TODO if node.rval is Constant of some datatype, move it to mem directly
222 self.genexprcode(node.rval) # Calculate the value that has to be stored.
223 self.storeRegInDesignator(node.rval.reg, node.lval)
224 self.freereg(node.rval)
225 else:
226 Error('Assignments of other types not implemented')
227 # TODO if left and right are designators, do some sort of memcpy.
228
229 elif type(node) is IfStatement:
230 self.genexprcode(node.condition)
231 self.addCode( cmpreg64(node.condition.reg, 1) )
232 self.freereg(node.condition)
233 if node.falsestatement:
234 # If with else clause
235 self.addCode( nearjump(0x0, condition='NE') ) # if Not Equal jump to false
236 rip1 = self.rip
237 fixloc1 = self.rip - 4
238 self.gencode(node.truestatement)
239 self.addCode( nearjump( 0x0 ) ) # jump over false code
240 fixloc2 = self.rip - 4
241 self.fixCode(fixloc1, imm32(self.rip - rip1))
242 rip2 = self.rip
243 self.gencode(node.falsestatement)
244 self.fixCode(fixloc2, imm32(self.rip - rip2))
245 else:
246 # If without else clause
247 self.addCode( nearjump(0x0, condition='NE') ) # if Not Equal jump to false
248 rip1 = self.rip
249 fixloc1 = self.rip - 4
250 self.gencode(node.truestatement)
251 self.fixCode(fixloc1, imm32(self.rip - rip1)) # Fixup near jump over true code.
252
253 elif isinstance(node, WhileStatement):
254 rip1 = self.rip # Store the start of the while loop
255 self.genexprcode(node.condition)
256 self.addCode( cmpreg64(node.condition.reg, 1) ) # Test condition for true-ness
257 self.freereg(node.condition)
258 self.addCode( nearjump(0x0, condition='NE') ) # If Not Equal jump over while code AND jump back (fix later)
259 fixloc1 = self.rip - 4
260 rip2 = self.rip
261 self.gencode(node.dostatements)
262 self.addCode( nearjump(0x0) ) # JMP to condition, fix exact jump position below
263 fixloc2 = self.rip - 4
264 rip3 = self.rip # end of while loop
265 self.fixCode(fixloc2, imm32(rip1 - rip3)) # Fixup jump to start of while loop
266 self.fixCode(fixloc1, imm32(rip3 - rip2)) # Fixup jump out of while loop
267
268 elif type(node) is ForStatement:
269 # Initial load of iterator variable:
270 self.genexprcode(node.begin)
271 self.genexprcode(node.end)
272 # TODO: link reg with variable so that a register is used instead of a variable
273 iterreg = node.begin.reg # Get the register used for the loop
274 #self.addCode(cmpreg64(iterreg, node.endvalue))
275 rip1 = self.rip
276 self.gencode(node.statements)
277 #self.loadDesignatorInReg(node.
278 #self.addCode( addreg64(node.variable, node.increment) )
279 self.addCode(nearjump(0x0))
280 fixloc1 = self.rip - 4
281 rip2 = self.rip
282 self.fixCode(fixloc1, imm32(rip1 - rip2))
283
284 self.freereg(node.begin) # Release register used in loop
285 self.freereg(node.end)
286 Error('No implementation of FOR statement')
287
288 elif type(node) is AsmCode:
289 def processOperand(op):
290 if type(op) is list:
291 if type(op[0]) is Variable:
292 var = op[0]
293 if var.isLocal:
294 return ['rbp', var.offset]
295 else:
296 Error('Can only use local variables in inline assembler')
297 return op
298 for asmline in node.asmcode:
299 opcode, operands = asmline
300 operands = [processOperand(opx) for opx in operands]
301 print('assembling', opcode, *operands)
302 func,nargs = opcodes[opcode]
303 code = func(*operands)
304 self.addCode(code)
305
306 elif isinstance(node, EmptyStatement):
307 pass
308
309 elif type(node) is StringConstant:
310 self.strings.append(node)
311 self.data.append(node.value) # Add string to the data section
312
313 elif type(node) is Designator:
314 if len(node.selectors) > 0:
315 self.getreg(node)
316 # Load starting address
317 if node.obj.isLocal:
318 self.addCode( leareg64(node.reg, ['rbp', node.obj.offset]) )
319 else:
320 # Global variables need to be relocated...
321 self.addCode(leareg64(node.reg, ['RIP', 0]))
322 self.fixCode(self.rip - 4, imm32(node.obj.offset - self.rip))
323 # Loop over all designators..
324 for selector in node.selectors:
325 if type(selector) is Index:
326 # Deref an array index
327 self.genexprcode(selector.index)
328 self.getreg(selector)
329 self.addCode( mov(selector.reg, selector.typ.elementType.size) )
330 self.addCode( imulreg64(selector.reg, selector.index.reg ) )
331 self.freereg(selector.index)
332 self.addCode(addreg64(node.reg, selector.reg))
333 self.freereg(selector)
334 elif type(selector) is Field:
335 print('Field')
336 Error('Field not implemented')
337 else:
338 Error('Unknown selector')
339 else:
340 Error('Can only gencode for designator with selectors')
341
342 else:
343 print('not generating code for {0}'.format(node))
344
345 def generateIr(self, ast):
346 """ ir generation front end """
347 return self.gencode(ast)
348