merge intbount-improvements-3

refactor the intbounds analyzer a little bit, add some optimizations for
int_neg and int_invert

6 files changed, 251 insertions, 84 deletions

diff --git a/rpython/jit/metainterp/optimizeopt/intbounds.py b/rpython/jit/metainterp/optimizeopt/intbounds.py
index a9445a5f8e..5e99a4999f 100644
--- a/rpython/jit/metainterp/optimizeopt/intbounds.py
+++ b/rpython/jit/metainterp/optimizeopt/intbounds.py
@@ -1,8 +1,7 @@
 import sys
 from rpython.jit.metainterp.history import ConstInt
 from rpython.jit.metainterp.optimize import InvalidLoop
-from rpython.jit.metainterp.optimizeopt.intutils import (IntBound,
-    IntLowerBound, IntUpperBound, ConstIntBound)
+from rpython.jit.metainterp.optimizeopt.intutils import IntBound
 from rpython.jit.metainterp.optimizeopt.optimizer import (Optimization, CONST_1,
     CONST_0)
 from rpython.jit.metainterp.optimizeopt.util import (
@@ -43,8 +42,8 @@ class OptIntBounds(Optimization):
         #        but the bounds produced by all instructions where box is
         #        an argument might also be tighten
         b = self.getintbound(box)
-        if b.has_lower and b.has_upper and b.lower == b.upper:
-            self.make_constant_int(box, b.lower)
+        if b.is_constant():
+            self.make_constant_int(box, b.getint())
 
         box1 = self.optimizer.as_operation(box)
         if box1 is not None:
@@ -214,7 +213,7 @@ class OptIntBounds(Optimization):
         # intbound.lshift_bound checks for an overflow and if the
         # lshift can be proven not to overflow sets b.has_upper and
         # b.has_lower
-        if b.has_lower and b.has_upper:
+        if b.bounded():
             # Synthesize the reverse op for optimize_default to reuse
             self.pure_from_args(rop.INT_RSHIFT,
                                 [op, arg1], arg0)
@@ -223,7 +222,7 @@ class OptIntBounds(Optimization):
         b1 = self.getintbound(op.getarg(0))
         b2 = self.getintbound(op.getarg(1))
         b = b1.rshift_bound(b2)
-        if b.has_lower and b.has_upper and b.lower == b.upper:
+        if b.is_constant():
             # constant result (likely 0, for rshifts that kill all bits)
             self.make_constant_int(op, b.lower)
             return None
@@ -489,7 +488,30 @@ class OptIntBounds(Optimization):
         numbits = op.getarg(1).getint() * 8
         start = -(1 << (numbits - 1))
         stop = 1 << (numbits - 1)
-        bounds = IntBound(start, stop - 1)
+        bres = self.getintbound(op)
+        bres.intersect_const(start, stop - 1)
+
+    def postprocess_INT_INVERT(self, op):
+        b = self.getintbound(op.getarg(0))
+        bounds = b.invert_bound()
+        bres = self.getintbound(op)
+        bres.intersect(bounds)
+
+    def propagate_bounds_INT_INVERT(self, op):
+        b = self.getintbound(op.getarg(0))
+        bres = self.getintbound(op)
+        bounds = bres.invert_bound()
+        b.intersect(bounds)
+
+    def propagate_bounds_INT_NEG(self, op):
+        b = self.getintbound(op.getarg(0))
+        bres = self.getintbound(op)
+        bounds = bres.neg_bound()
+        b.intersect(bounds)
+
+    def postprocess_INT_NEG(self, op):
+        b = self.getintbound(op.getarg(0))
+        bounds = b.neg_bound()
         bres = self.getintbound(op)
         bres.intersect(bounds)
 
@@ -523,12 +545,11 @@ class OptIntBounds(Optimization):
         v1 = self.getintbound(op)
         v2 = getptrinfo(op.getarg(0))
         intbound = self.getintbound(op.getarg(1))
-        if (intbound.has_lower and v2 is not None and
-            v2.getlenbound(vstring.mode_string) is not None):
-            lb = IntLowerBound(intbound.lower + 1)
-            v2.getlenbound(vstring.mode_string).make_ge(lb)
-        v1.make_ge(IntLowerBound(0))
-        v1.make_lt(IntUpperBound(256))
+        if intbound.has_lower and v2 is not None:
+            lenbound = v2.getlenbound(vstring.mode_string)
+            if lenbound is not None:
+                lenbound.make_gt_const(intbound.lower)
+        v1.intersect_const(0, 255)
 
     def optimize_GETFIELD_RAW_I(self, op):
         return self.emit(op)
@@ -537,8 +558,7 @@ class OptIntBounds(Optimization):
         descr = op.getdescr()
         if descr.is_integer_bounded():
             b1 = self.getintbound(op)
-            b1.make_ge(IntLowerBound(descr.get_integer_min()))
-            b1.make_le(IntUpperBound(descr.get_integer_max()))
+            b1.intersect_const(descr.get_integer_min(), descr.get_integer_max())
 
     optimize_GETFIELD_RAW_F = optimize_GETFIELD_RAW_I
     optimize_GETFIELD_RAW_R = optimize_GETFIELD_RAW_I
@@ -567,8 +587,7 @@ class OptIntBounds(Optimization):
         descr = op.getdescr()
         if descr and descr.is_item_integer_bounded():
             intbound = self.getintbound(op)
-            intbound.make_ge(IntLowerBound(descr.get_item_integer_min()))
-            intbound.make_le(IntUpperBound(descr.get_item_integer_max()))
+            intbound.intersect_const(descr.get_item_integer_min(), descr.get_item_integer_max())
 
     optimize_GETARRAYITEM_RAW_F = optimize_GETARRAYITEM_RAW_I
     optimize_GETARRAYITEM_GC_I = optimize_GETARRAYITEM_RAW_I
@@ -585,13 +604,13 @@ class OptIntBounds(Optimization):
 
     def postprocess_UNICODEGETITEM(self, op):
         b1 = self.getintbound(op)
-        b1.make_ge(IntLowerBound(0))
+        b1.make_ge_const(0)
         v2 = getptrinfo(op.getarg(0))
         intbound = self.getintbound(op.getarg(1))
-        if (intbound.has_lower and v2 is not None and
-            v2.getlenbound(vstring.mode_unicode) is not None):
-            lb = IntLowerBound(intbound.lower + 1)
-            v2.getlenbound(vstring.mode_unicode).make_ge(lb)
+        if intbound.has_lower and v2 is not None:
+            lenbound = v2.getlenbound(vstring.mode_unicode)
+            if lenbound is not None:
+                lenbound.make_gt_const(intbound.lower)
 
     def make_int_lt(self, box1, box2):
         b1 = self.getintbound(box1)
@@ -655,7 +674,7 @@ class OptIntBounds(Optimization):
         b2 = self.getintbound(box2)
         if b2.known_nonnegative:
             b1 = self.getintbound(box1)
-            if b1.make_lt(b2) | b1.make_ge(IntBound(0, 0)):
+            if b1.make_lt(b2) | b1.make_ge_const(0):
                 self.propagate_bounds_backward(box1)
             #if b2.make_gt(b1):
             # ^^ probably correct but I fail to see a case where it is helpful
@@ -666,7 +685,7 @@ class OptIntBounds(Optimization):
         b2 = self.getintbound(box2)
         if b2.known_nonnegative:
             b1 = self.getintbound(box1)
-            if b1.make_le(b2) | b1.make_ge(IntBound(0, 0)):
+            if b1.make_le(b2) | b1.make_ge_const(0):
                 self.propagate_bounds_backward(box1)
             #if b2.make_ge(b1):
             # ^^ probably correct but I fail to see a case where it is helpful
@@ -718,25 +737,23 @@ class OptIntBounds(Optimization):
 
     def propagate_bounds_INT_EQ(self, op):
         r = self.getintbound(op)
-        if r.is_constant():
-            if r.equal(1):
-                b1 = self.getintbound(op.getarg(0))
-                b2 = self.getintbound(op.getarg(1))
-                if b1.intersect(b2):
-                    self.propagate_bounds_backward(op.getarg(0))
-                if b2.intersect(b1):
-                    self.propagate_bounds_backward(op.getarg(1))
+        if r.equal(1):
+            b1 = self.getintbound(op.getarg(0))
+            b2 = self.getintbound(op.getarg(1))
+            if b1.intersect(b2):
+                self.propagate_bounds_backward(op.getarg(0))
+            if b2.intersect(b1):
+                self.propagate_bounds_backward(op.getarg(1))
 
     def propagate_bounds_INT_NE(self, op):
         r = self.getintbound(op)
-        if r.is_constant():
-            if r.equal(0):
-                b1 = self.getintbound(op.getarg(0))
-                b2 = self.getintbound(op.getarg(1))
-                if b1.intersect(b2):
-                    self.propagate_bounds_backward(op.getarg(0))
-                if b2.intersect(b1):
-                    self.propagate_bounds_backward(op.getarg(1))
+        if r.equal(0):
+            b1 = self.getintbound(op.getarg(0))
+            b2 = self.getintbound(op.getarg(1))
+            if b1.intersect(b2):
+                self.propagate_bounds_backward(op.getarg(0))
+            if b2.intersect(b1):
+                self.propagate_bounds_backward(op.getarg(1))
 
     def _propagate_int_is_true_or_zero(self, op, valnonzero, valzero):
         if self.is_raw_ptr(op.getarg(0)):
@@ -746,16 +763,10 @@ class OptIntBounds(Optimization):
             if r.getint() == valnonzero:
                 b1 = self.getintbound(op.getarg(0))
                 if b1.known_nonnegative():
-                    b1.make_gt(IntBound(0, 0))
+                    b1.make_gt_const(0)
                     self.propagate_bounds_backward(op.getarg(0))
             elif r.getint() == valzero:
-                b1 = self.getintbound(op.getarg(0))
-                # XXX remove this hack maybe?
-                # Clever hack, we can't use self.make_constant_int yet because
-                # the args aren't in the values dictionary yet so it runs into
-                # an assert, this is a clever way of expressing the same thing.
-                b1.make_ge(IntBound(0, 0))
-                b1.make_lt(IntBound(1, 1))
+                self.make_constant_int(op.getarg(0), 0)
                 self.propagate_bounds_backward(op.getarg(0))
 
     def propagate_bounds_INT_IS_TRUE(self, op):
diff --git a/rpython/jit/metainterp/optimizeopt/intutils.py b/rpython/jit/metainterp/optimizeopt/intutils.py
index 2590aad376..9f2ced0f00 100644
--- a/rpython/jit/metainterp/optimizeopt/intutils.py
+++ b/rpython/jit/metainterp/optimizeopt/intutils.py
@@ -109,14 +109,34 @@ class IntBound(AbstractInfo):
     def bounded(self):
         return self.has_lower and self.has_upper
 
+    def known_lt_const(self, other):
+        if self.has_upper:
+            return self.upper < other
+        return False
+
+    def known_le_const(self, other):
+        if self.has_upper:
+            return self.upper <= other
+        return False
+
+    def known_gt_const(self, other):
+        if self.has_lower:
+            return self.lower > other
+        return False
+
+    def known_ge_const(self, other):
+        if self.has_upper:
+            return self.upper >= other
+        return False
+
     def known_lt(self, other):
-        if self.has_upper and other.has_lower and self.upper < other.lower:
-            return True
+        if other.has_lower:
+            return self.known_lt_const(other.lower)
         return False
 
     def known_le(self, other):
-        if self.has_upper and other.has_lower and self.upper <= other.lower:
-            return True
+        if other.has_lower:
+            return self.known_le_const(other.lower)
         return False
 
     def known_gt(self, other):
@@ -130,19 +150,18 @@ class IntBound(AbstractInfo):
 
     def intersect(self, other):
         r = False
-
         if other.has_lower:
-            if other.lower > self.lower or not self.has_lower:
-                self.lower = other.lower
-                self.has_lower = True
+            if self.make_ge_const(other.lower):
                 r = True
-
         if other.has_upper:
-            if other.upper < self.upper or not self.has_upper:
-                self.upper = other.upper
-                self.has_upper = True
+            if self.make_le_const(other.upper):
                 r = True
+        return r
 
+    def intersect_const(self, lower, upper):
+        r = self.make_ge_const(lower)
+        if self.make_le_const(upper):
+            r = True
         return r
 
     def add(self, offset):
@@ -241,10 +260,9 @@ class IntBound(AbstractInfo):
         return r
 
     def lshift_bound(self, other):
-        if self.has_upper and self.has_lower and \
-           other.has_upper and other.has_lower and \
+        if self.bounded() and other.bounded() and \
            other.known_nonnegative() and \
-           other.known_lt(IntBound(LONG_BIT, LONG_BIT)):
+           other.known_lt_const(LONG_BIT):
             try:
                 vals = (ovfcheck(self.upper << other.upper),
                         ovfcheck(self.upper << other.lower),
@@ -257,10 +275,9 @@ class IntBound(AbstractInfo):
             return IntUnbounded()
 
     def rshift_bound(self, other):
-        if self.has_upper and self.has_lower and \
-           other.has_upper and other.has_lower and \
+        if self.bounded() and other.bounded() and \
            other.known_nonnegative() and \
-           other.known_lt(IntBound(LONG_BIT, LONG_BIT)):
+           other.known_lt_const(LONG_BIT):
             vals = (self.upper >> other.upper,
                     self.upper >> other.lower,
                     self.lower >> other.upper,
@@ -292,6 +309,36 @@ class IntBound(AbstractInfo):
                 r.make_ge_const(0)
         return r
 
+    def invert_bound(self):
+        res = self.clone()
+        res.has_upper = False
+        if self.has_lower:
+            res.upper = ~self.lower
+            res.has_upper = True
+        res.has_lower = False
+        if self.has_upper:
+            res.lower = ~self.upper
+            res.has_lower = True
+        return res
+
+    def neg_bound(self):
+        res = self.clone()
+        res.has_upper = False
+        if self.has_lower:
+            try:
+                res.upper = ovfcheck(-self.lower)
+                res.has_upper = True
+            except OverflowError:
+                pass
+        res.has_lower = False
+        if self.has_upper:
+            try:
+                res.lower = ovfcheck(-self.upper)
+                res.has_lower = True
+            except OverflowError:
+                pass
+        return res
+
     def contains(self, val):
         if not we_are_translated():
             assert not isinstance(val, long)
@@ -356,7 +403,7 @@ class IntBound(AbstractInfo):
 
     def is_bool(self):
         return (self.bounded() and self.known_nonnegative() and
-                self.known_le(ConstIntBound(1)))
+                self.known_le_const(1))
 
     def make_bool(self):
         self.intersect(IntBound(0, 1))
@@ -367,11 +414,11 @@ class IntBound(AbstractInfo):
         return ConstInt(self.getint())
 
     def getnullness(self):
-        if self.known_gt(IntBound(0, 0)) or \
-           self.known_lt(IntBound(0, 0)):
+        if self.known_gt_const(0) or \
+           self.known_lt_const(0):
             return INFO_NONNULL
         if self.known_nonnegative() and \
-           self.known_le(IntBound(0, 0)):
+           self.known_le_const(0):
             return INFO_NULL
         return INFO_UNKNOWN
 
diff --git a/rpython/jit/metainterp/optimizeopt/rewrite.py b/rpython/jit/metainterp/optimizeopt/rewrite.py
index 47b88dbfdf..abb5766fd3 100644
--- a/rpython/jit/metainterp/optimizeopt/rewrite.py
+++ b/rpython/jit/metainterp/optimizeopt/rewrite.py
@@ -4,7 +4,6 @@ from rpython.jit.metainterp import compile
 from rpython.jit.metainterp.history import (
     Const, ConstInt, make_hashable_int, ConstFloat, CONST_NULL)
 from rpython.jit.metainterp.optimize import InvalidLoop
-from rpython.jit.metainterp.optimizeopt.intutils import IntBound
 from rpython.jit.metainterp.optimizeopt.optimizer import (
     Optimization, OptimizationResult, REMOVED, CONST_0, CONST_1)
 from rpython.jit.metainterp.optimizeopt.info import (
@@ -239,9 +238,9 @@ class OptRewrite(Optimization):
         b1 = self.getintbound(op.getarg(0))
         b2 = self.getintbound(op.getarg(1))
 
-        if b2.is_constant() and b2.getint() == 0:
+        if b2.equal(0):
             self.make_equal_to(op, op.getarg(0))
-        elif b1.is_constant() and b1.getint() == 0:
+        elif b1.equal(0):
             self.make_constant_int(op, 0)
         else:
             return self.emit(op)
@@ -250,9 +249,9 @@ class OptRewrite(Optimization):
         b1 = self.getintbound(op.getarg(0))
         b2 = self.getintbound(op.getarg(1))
 
-        if b2.is_constant() and b2.getint() == 0:
+        if b2.equal(0):
             self.make_equal_to(op, op.getarg(0))
-        elif b1.is_constant() and b1.getint() == 0:
+        elif b1.equal(0):
             self.make_constant_int(op, 0)
         else:
             return self.emit(op)
@@ -268,6 +267,9 @@ class OptRewrite(Optimization):
         else:
             return self.emit(op)
 
+    def postprocess_INT_INVERT(self, op):
+        self.optimizer.pure_from_args(rop.INT_INVERT, [op], op.getarg(0))
+
     def optimize_FLOAT_MUL(self, op):
         arg1 = op.getarg(0)
         arg2 = op.getarg(1)
@@ -837,7 +839,7 @@ class OptRewrite(Optimization):
         arg2 = op.getarg(2)
         b2 = self.getintbound(arg2)
 
-        if b1.is_constant() and b1.getint() == 0:
+        if b1.equal(0):
             self.make_constant_int(op, 0)
             self.last_emitted_operation = REMOVED
             return True
@@ -859,7 +861,7 @@ class OptRewrite(Optimization):
             return True
         else:
             from rpython.jit.metainterp.optimizeopt import intdiv
-            known_nonneg = b1.known_ge(IntBound(0, 0))
+            known_nonneg = b1.known_nonnegative()
             operations = intdiv.division_operations(arg1, val, known_nonneg)
             newop = None
             for newop in operations:
@@ -873,7 +875,7 @@ class OptRewrite(Optimization):
         arg2 = op.getarg(2)
         b2 = self.getintbound(arg2)
 
-        if b1.is_constant() and b1.getint() == 0:
+        if b1.equal(0):
             self.make_constant_int(op, 0)
             self.last_emitted_operation = REMOVED
             return True
@@ -899,7 +901,7 @@ class OptRewrite(Optimization):
             return True
         else:
             from rpython.jit.metainterp.optimizeopt import intdiv
-            known_nonneg = b1.known_ge(IntBound(0, 0))
+            known_nonneg = b1.known_nonnegative()
             operations = intdiv.modulo_operations(arg1, val, known_nonneg)
             newop = None
             for newop in operations:
diff --git a/rpython/jit/metainterp/optimizeopt/test/test_intbound.py b/rpython/jit/metainterp/optimizeopt/test/test_intbound.py
index 45b1635136..0b782b4e60 100644
--- a/rpython/jit/metainterp/optimizeopt/test/test_intbound.py
+++ b/rpython/jit/metainterp/optimizeopt/test/test_intbound.py
@@ -371,6 +371,19 @@ def test_next_pow2_m1():
     assert next_pow2_m1((1 << 32) - 5) == (1 << 32) - 1
     assert next_pow2_m1((1 << 64) - 1) == (1 << 64) - 1
 
+def test_invert_bound():
+    for _, _, b1 in some_bounds():
+        b2 = b1.invert_bound()
+        for n1 in nbr:
+            if b1.contains(n1):
+                assert b2.contains(~n1)
+
+def test_neg_bound():
+    for _, _, b1 in some_bounds():
+        b2 = b1.neg_bound()
+        for n1 in nbr:
+            if b1.contains(n1):
+                assert b2.contains(-n1)
 
 @given(bound_with_contained_number, bound_with_contained_number)
 def test_make_random(t1, t2):
@@ -464,3 +477,18 @@ def test_or_bound_random(t1, t2):
     assert b3.contains(r)
     r = n1 ^ n2
     assert b3.contains(r)
+
+@given(bound_with_contained_number)
+def test_invert_bound_random(t1):
+    b1, n1 = t1
+    b2 = b1.invert_bound()
+    assert b2.contains(~n1)
+
+@given(bound_with_contained_number)
+def test_neg_bound_random(t1):
+    b1, n1 = t1
+    b2 = b1.neg_bound()
+    if n1 != -sys.maxint - 1:
+        assert b2.contains(-n1)
+    else:
+        assert not b2.has_lower
diff --git a/rpython/jit/metainterp/optimizeopt/test/test_optimizebasic.py b/rpython/jit/metainterp/optimizeopt/test/test_optimizebasic.py
index 4daf55065d..ac115639fc 100644
--- a/rpython/jit/metainterp/optimizeopt/test/test_optimizebasic.py
+++ b/rpython/jit/metainterp/optimizeopt/test/test_optimizebasic.py
@@ -6325,3 +6325,81 @@ class TestOptimizeBasic(BaseTestBasic):
         escape_i(i0)
         """
         self.optimize_loop(ops, expected)
+
+    def test_int_invert(self):
+        ops = """
+        [p0]
+        i1 = arraylen_gc(p0, descr=arraydescr) # known >= 0
+        i2 = int_invert(i1)
+        i3 = int_lt(i2, 0)
+        guard_true(i3) []
+        """
+        expected = """
+        [p0]
+        i1 = arraylen_gc(p0, descr=arraydescr) # known >= 0
+        i2 = int_invert(i1)
+        """
+        self.optimize_loop(ops, expected)
+
+    def test_int_invert_invert(self):
+        ops = """
+        [i1]
+        i2 = int_invert(i1)
+        i3 = int_invert(i2)
+        escape_i(i3)
+        """
+        expected = """
+        [i1]
+        i2 = int_invert(i1)
+        escape_i(i1)
+        """
+        self.optimize_loop(ops, expected)
+
+    def test_int_invert_postprocess(self):
+        ops = """
+        [i1]
+        i2 = int_invert(i1)
+        i3 = int_lt(i2, 0)
+        guard_true(i3) []
+        i4 = int_ge(i1, 0)
+        guard_true(i4) []
+        """
+        expected = """
+        [i1]
+        i2 = int_invert(i1)
+        i3 = int_lt(i2, 0)
+        guard_true(i3) []
+        """
+        self.optimize_loop(ops, expected)
+
+    def test_int_neg(self):
+        ops = """
+        [p0]
+        i1 = arraylen_gc(p0, descr=arraydescr) # known >= 0
+        i2 = int_neg(i1)
+        i3 = int_le(i2, 0)
+        guard_true(i3) []
+        """
+        expected = """
+        [p0]
+        i1 = arraylen_gc(p0, descr=arraydescr) # known >= 0
+        i2 = int_neg(i1)
+        """
+        self.optimize_loop(ops, expected)
+
+    def test_int_neg_postprocess(self):
+        ops = """
+        [i1]
+        i2 = int_neg(i1)
+        i3 = int_le(i2, 0)
+        guard_true(i3) []
+        i4 = int_ge(i1, 0)
+        guard_true(i4) []
+        """
+        expected = """
+        [i1]
+        i2 = int_neg(i1)
+        i3 = int_le(i2, 0)
+        guard_true(i3) []
+        """
+        self.optimize_loop(ops, expected)
diff --git a/rpython/jit/metainterp/optimizeopt/test/test_optimizeopt.py b/rpython/jit/metainterp/optimizeopt/test/test_optimizeopt.py
index 4de28a02ba..3e1a2e64fd 100644
--- a/rpython/jit/metainterp/optimizeopt/test/test_optimizeopt.py
+++ b/rpython/jit/metainterp/optimizeopt/test/test_optimizeopt.py
@@ -8327,7 +8327,7 @@ class TestOptimizeOpt(BaseTestWithUnroll):
         ops = """
         [p1, p2]
         i1 = getfield_gc_i(p1, descr=valuedescr)
-        setfield_gc(p2, i1, descr=nextdescr)
+        setfield_gc(p2, i1, descr=valuedescr3)
         i2 = int_neg(i1)
         call_n(i2, descr=nonwritedescr)
         jump(p1, p2)
@@ -8335,7 +8335,7 @@ class TestOptimizeOpt(BaseTestWithUnroll):
         expected = """
         [p1, p2, i2, i1]
         call_n(i2, descr=nonwritedescr)
-        setfield_gc(p2, i1, descr=nextdescr)
+        setfield_gc(p2, i1, descr=valuedescr3)
         jump(p1, p2, i2, i1)
         """
         self.optimize_loop(ops, expected)
@@ -8346,17 +8346,18 @@ class TestOptimizeOpt(BaseTestWithUnroll):
         # potential short boxes during tests
         ops = """
         [p1, p2]
-        i1 = getfield_gc_i(p1, descr=nextdescr)
+        i1 = getfield_gc_i(p1, descr=valuedescr3)
         setfield_gc(p2, i1, descr=valuedescr)
         i2 = int_neg(i1)
         call_n(i2, descr=nonwritedescr)
         jump(p1, p2)
         """
         expected = """
-        [p1, p2, i2, i1]
+        [p1, p2, i1]
+        i2 = int_neg(i1)
         call_n(i2, descr=nonwritedescr)
         setfield_gc(p2, i1, descr=valuedescr)
-        jump(p1, p2, i2, i1)
+        jump(p1, p2, i1)
         """
         self.optimize_loop(ops, expected)