diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/compiler/pyassem.py | 69 |
1 files changed, 51 insertions, 18 deletions
diff --git a/Lib/compiler/pyassem.py b/Lib/compiler/pyassem.py index d9d294b..cc2d108 100644 --- a/Lib/compiler/pyassem.py +++ b/Lib/compiler/pyassem.py @@ -196,7 +196,6 @@ class FlowGraph: chains.remove(c) chains.insert(goes_before, c) - del blocks[:] for c in chains: for b in c: @@ -374,6 +373,7 @@ class PyFlowGraph(FlowGraph): def getCode(self): """Get a Python code object""" if self.stage == RAW: + self.computeStackDepth() self.flattenGraph() if self.stage == FLAT: self.convertArgs() @@ -401,6 +401,36 @@ class PyFlowGraph(FlowGraph): if io: sys.stdout = save + def computeStackDepth(self): + """Compute the max stack depth. + + Approach is to compute the stack effect of each basic block. + Then find the path through the code with the largest total + effect. + """ + depth = {} + exit = None + for b in self.getBlocks(): + depth[b] = findDepth(b.getInstructions()) + + seen = {} + + def max_depth(b, d): + if seen.has_key(b): + return d + seen[b] = 1 + d = d + depth[b] + children = b.get_children() + if children: + return max([max_depth(c, d) for c in children]) + else: + if not b.label == "exit": + return max_depth(self.exit, d) + else: + return d + + self.stacksize = max_depth(self.entry, 0) + def flattenGraph(self): """Arrange the blocks in order and resolve jumps""" assert self.stage == RAW @@ -432,7 +462,6 @@ class PyFlowGraph(FlowGraph): insts[i] = opname, offset elif self.hasjabs.has_elt(opname): insts[i] = opname, begin[inst[1]] - self.stacksize = findDepth(self.insts) self.stage = FLAT hasjrel = misc.Set() @@ -693,21 +722,17 @@ class StackDepthTracker: # XXX 1. need to keep track of stack depth on jumps # XXX 2. at least partly as a result, this code is broken - def findDepth(self, insts): + def findDepth(self, insts, debug=0): depth = 0 maxDepth = 0 for i in insts: opname = i[0] - delta = self.effect.get(opname, 0) - if delta > 1: - depth = depth + delta - elif delta < 0: - if depth > maxDepth: - maxDepth = depth + if debug: + print i, + delta = self.effect.get(opname, None) + if delta is not None: depth = depth + delta else: - if depth > maxDepth: - maxDepth = depth # now check patterns for pat, pat_delta in self.patterns: if opname[:len(pat)] == pat: @@ -715,12 +740,14 @@ class StackDepthTracker: depth = depth + delta break # if we still haven't found a match - if delta == 0: + if delta is None: meth = getattr(self, opname, None) if meth is not None: depth = depth + meth(i[1]) - if depth < 0: - depth = 0 + if depth > maxDepth: + maxDepth = depth + if debug: + print depth, maxDepth return maxDepth effect = { @@ -754,6 +781,7 @@ class StackDepthTracker: 'IMPORT_STAR': -1, 'IMPORT_NAME': 0, 'IMPORT_FROM': 1, + 'LOAD_ATTR': 0, # unlike other loads # close enough... 'SETUP_EXCEPT': 3, 'SETUP_FINALLY': 3, @@ -773,19 +801,24 @@ class StackDepthTracker: return -count+1 def CALL_FUNCTION(self, argc): hi, lo = divmod(argc, 256) - return lo + hi * 2 + return -(lo + hi * 2) def CALL_FUNCTION_VAR(self, argc): - return self.CALL_FUNCTION(argc)+1 + return self.CALL_FUNCTION(argc)-1 def CALL_FUNCTION_KW(self, argc): - return self.CALL_FUNCTION(argc)+1 + return self.CALL_FUNCTION(argc)-1 def CALL_FUNCTION_VAR_KW(self, argc): - return self.CALL_FUNCTION(argc)+2 + return self.CALL_FUNCTION(argc)-2 def MAKE_FUNCTION(self, argc): return -argc + def MAKE_CLOSURE(self, argc): + # XXX need to account for free variables too! + return -argc def BUILD_SLICE(self, argc): if argc == 2: return -1 elif argc == 3: return -2 + def DUP_TOPX(self, argc): + return argc findDepth = StackDepthTracker().findDepth |