Backport r69961 to trunk, replacing JUMP_IF_{TRUE,FALSE} with
POP_JUMP_IF_{TRUE,FALSE} and JUMP_IF_{TRUE,FALSE}_OR_POP. This avoids executing
a POP_TOP on each conditional and sometimes allows the peephole optimizer to
skip a JUMP_ABSOLUTE entirely. It speeds up list comprehensions significantly.
diff --git a/Lib/compiler/pyassem.py b/Lib/compiler/pyassem.py
index 5098f2c..be0255d 100644
--- a/Lib/compiler/pyassem.py
+++ b/Lib/compiler/pyassem.py
@@ -122,6 +122,9 @@
for b in remaining:
if __debug__ and b.next:
assert b is b.next[0].prev[0], (b, b.next)
+ # Make sure every block appears in dominators, even if no
+ # other block must precede it.
+ dominators.setdefault(b, set())
# preceeding blocks dominate following blocks
for c in b.get_followers():
while 1:
diff --git a/Lib/compiler/pycodegen.py b/Lib/compiler/pycodegen.py
index 6d5a41c..81234d1 100644
--- a/Lib/compiler/pycodegen.py
+++ b/Lib/compiler/pycodegen.py
@@ -421,13 +421,11 @@
self.set_lineno(test)
self.visit(test)
nextTest = self.newBlock()
- self.emit('JUMP_IF_FALSE', nextTest)
+ self.emit('POP_JUMP_IF_FALSE', nextTest)
self.nextBlock()
- self.emit('POP_TOP')
self.visit(suite)
self.emit('JUMP_FORWARD', end)
self.startBlock(nextTest)
- self.emit('POP_TOP')
if node.else_:
self.visit(node.else_)
self.nextBlock(end)
@@ -446,15 +444,13 @@
self.set_lineno(node, force=True)
self.visit(node.test)
- self.emit('JUMP_IF_FALSE', else_ or after)
+ self.emit('POP_JUMP_IF_FALSE', else_ or after)
self.nextBlock()
- self.emit('POP_TOP')
self.visit(node.body)
self.emit('JUMP_ABSOLUTE', loop)
self.startBlock(else_) # or just the POPs if not else clause
- self.emit('POP_TOP')
self.emit('POP_BLOCK')
self.setups.pop()
if node.else_:
@@ -525,26 +521,23 @@
self.visit(child)
self.emit(jump, end)
self.nextBlock()
- self.emit('POP_TOP')
self.visit(node.nodes[-1])
self.nextBlock(end)
def visitAnd(self, node):
- self.visitTest(node, 'JUMP_IF_FALSE')
+ self.visitTest(node, 'JUMP_IF_FALSE_OR_POP')
def visitOr(self, node):
- self.visitTest(node, 'JUMP_IF_TRUE')
+ self.visitTest(node, 'JUMP_IF_TRUE_OR_POP')
def visitIfExp(self, node):
endblock = self.newBlock()
elseblock = self.newBlock()
self.visit(node.test)
- self.emit('JUMP_IF_FALSE', elseblock)
- self.emit('POP_TOP')
+ self.emit('POP_JUMP_IF_FALSE', elseblock)
self.visit(node.then)
self.emit('JUMP_FORWARD', endblock)
self.nextBlock(elseblock)
- self.emit('POP_TOP')
self.visit(node.else_)
self.nextBlock(endblock)
@@ -556,9 +549,8 @@
self.emit('DUP_TOP')
self.emit('ROT_THREE')
self.emit('COMPARE_OP', op)
- self.emit('JUMP_IF_FALSE', cleanup)
+ self.emit('JUMP_IF_FALSE_OR_POP', cleanup)
self.nextBlock()
- self.emit('POP_TOP')
# now do the last comparison
if node.ops:
op, code = node.ops[-1]
@@ -593,11 +585,7 @@
for start, cont, anchor in stack:
if cont:
- skip_one = self.newBlock()
- self.emit('JUMP_FORWARD', skip_one)
- self.startBlock(cont)
- self.emit('POP_TOP')
- self.nextBlock(skip_one)
+ self.nextBlock(cont)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
@@ -617,9 +605,8 @@
def visitListCompIf(self, node, branch):
self.set_lineno(node, force=True)
self.visit(node.test)
- self.emit('JUMP_IF_FALSE', branch)
+ self.emit('POP_JUMP_IF_FALSE', branch)
self.newBlock()
- self.emit('POP_TOP')
def _makeClosure(self, gen, args):
frees = gen.scope.get_free_vars()
@@ -665,11 +652,7 @@
for start, cont, anchor, end in stack:
if cont:
- skip_one = self.newBlock()
- self.emit('JUMP_FORWARD', skip_one)
- self.startBlock(cont)
- self.emit('POP_TOP')
- self.nextBlock(skip_one)
+ self.nextBlock(cont)
self.emit('JUMP_ABSOLUTE', start)
self.startBlock(anchor)
self.emit('POP_BLOCK')
@@ -702,9 +685,8 @@
def visitGenExprIf(self, node, branch):
self.set_lineno(node, force=True)
self.visit(node.test)
- self.emit('JUMP_IF_FALSE', branch)
+ self.emit('POP_JUMP_IF_FALSE', branch)
self.newBlock()
- self.emit('POP_TOP')
# exception related
@@ -719,9 +701,8 @@
# is a sort of renaming op.
self.nextBlock()
self.visit(node.test)
- self.emit('JUMP_IF_TRUE', end)
+ self.emit('POP_JUMP_IF_TRUE', end)
self.nextBlock()
- self.emit('POP_TOP')
self.emit('LOAD_GLOBAL', 'AssertionError')
if node.fail:
self.visit(node.fail)
@@ -729,7 +710,6 @@
else:
self.emit('RAISE_VARARGS', 1)
self.nextBlock(end)
- self.emit('POP_TOP')
def visitRaise(self, node):
self.set_lineno(node)
@@ -772,9 +752,8 @@
self.visit(expr)
self.emit('COMPARE_OP', 'exception match')
next = self.newBlock()
- self.emit('JUMP_IF_FALSE', next)
+ self.emit('POP_JUMP_IF_FALSE', next)
self.nextBlock()
- self.emit('POP_TOP')
self.emit('POP_TOP')
if target:
self.visit(target)
@@ -787,8 +766,6 @@
self.nextBlock(next)
else:
self.nextBlock()
- if expr: # XXX
- self.emit('POP_TOP')
self.emit('END_FINALLY')
if node.else_:
self.nextBlock(lElse)
diff --git a/Lib/opcode.py b/Lib/opcode.py
index d41383b..24d5dcc 100644
--- a/Lib/opcode.py
+++ b/Lib/opcode.py
@@ -146,9 +146,11 @@
name_op('IMPORT_FROM', 108) # Index in name list
jrel_op('JUMP_FORWARD', 110) # Number of bytes to skip
-jrel_op('JUMP_IF_FALSE', 111) # ""
-jrel_op('JUMP_IF_TRUE', 112) # ""
-jabs_op('JUMP_ABSOLUTE', 113) # Target byte offset from beginning of code
+jabs_op('JUMP_IF_FALSE_OR_POP', 111) # Target byte offset from beginning of code
+jabs_op('JUMP_IF_TRUE_OR_POP', 112) # ""
+jabs_op('JUMP_ABSOLUTE', 113) # ""
+jabs_op('POP_JUMP_IF_FALSE', 114) # ""
+jabs_op('POP_JUMP_IF_TRUE', 115) # ""
name_op('LOAD_GLOBAL', 116) # Index in name list
diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index 6fa437b..613d30a 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -54,25 +54,23 @@
dis_bug1333982 = """\
%-4d 0 LOAD_CONST 1 (0)
- 3 JUMP_IF_TRUE 33 (to 39)
- 6 POP_TOP
- 7 LOAD_GLOBAL 0 (AssertionError)
- 10 BUILD_LIST 0
- 13 LOAD_FAST 0 (x)
- 16 GET_ITER
- >> 17 FOR_ITER 12 (to 32)
- 20 STORE_FAST 1 (s)
- 23 LOAD_FAST 1 (s)
- 26 LIST_APPEND 2
- 29 JUMP_ABSOLUTE 17
+ 3 POP_JUMP_IF_TRUE 38
+ 6 LOAD_GLOBAL 0 (AssertionError)
+ 9 BUILD_LIST 0
+ 12 LOAD_FAST 0 (x)
+ 15 GET_ITER
+ >> 16 FOR_ITER 12 (to 31)
+ 19 STORE_FAST 1 (s)
+ 22 LOAD_FAST 1 (s)
+ 25 LIST_APPEND 2
+ 28 JUMP_ABSOLUTE 16
- %-4d >> 32 LOAD_CONST 2 (1)
- 35 BINARY_ADD
- 36 RAISE_VARARGS 2
- >> 39 POP_TOP
+ %-4d >> 31 LOAD_CONST 2 (1)
+ 34 BINARY_ADD
+ 35 RAISE_VARARGS 2
- %-4d 40 LOAD_CONST 0 (None)
- 43 RETURN_VALUE
+ %-4d >> 38 LOAD_CONST 0 (None)
+ 41 RETURN_VALUE
"""%(bug1333982.func_code.co_firstlineno + 1,
bug1333982.func_code.co_firstlineno + 2,
bug1333982.func_code.co_firstlineno + 3)
diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index c547984..6638a5a 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -19,15 +19,14 @@
class TestTranforms(unittest.TestCase):
def test_unot(self):
- # UNARY_NOT JUMP_IF_FALSE POP_TOP --> JUMP_IF_TRUE POP_TOP'
+ # UNARY_NOT POP_JUMP_IF_FALSE --> POP_JUMP_IF_TRUE
def unot(x):
if not x == 2:
del x
asm = disassemble(unot)
- for elem in ('UNARY_NOT', 'JUMP_IF_FALSE'):
+ for elem in ('UNARY_NOT', 'POP_JUMP_IF_FALSE'):
self.assert_(elem not in asm)
- for elem in ('JUMP_IF_TRUE', 'POP_TOP'):
- self.assert_(elem in asm)
+ self.assert_('POP_JUMP_IF_TRUE' in asm)
def test_elim_inversion_of_is_or_in(self):
for line, elem in (
@@ -56,13 +55,13 @@
self.assert_('LOAD_GLOBAL' not in disassemble(f))
def test_while_one(self):
- # Skip over: LOAD_CONST trueconst JUMP_IF_FALSE xx POP_TOP
+ # Skip over: LOAD_CONST trueconst POP_JUMP_IF_FALSE xx
def f():
while 1:
pass
return list
asm = disassemble(f)
- for elem in ('LOAD_CONST', 'JUMP_IF_FALSE'):
+ for elem in ('LOAD_CONST', 'POP_JUMP_IF_FALSE'):
self.assert_(elem not in asm)
for elem in ('JUMP_ABSOLUTE',):
self.assert_(elem in asm)