diff --git a/claripy/operations.py b/claripy/operations.py
index 217167c..5a3d108 100644
--- a/claripy/operations.py
+++ b/claripy/operations.py
@@ -333,6 +333,14 @@ def boolean_reverse_simplifier(body):
     if body.length == 8:
         return body
 
+    if body.op == 'Extract':
+        high,low = body.args[:2]
+        if high % 8 == 7 and low % 8 == 0:
+            if body.args[2].op == 'Reverse':
+                bits = body.args[2].args[0].size()
+                if bits % 8 == 0:
+                    return body.make_like(body.op,[bits - 1 - low,bits - 1 - high,body.args[2].args[0]])
+
     if body.op == 'Concat':
         if all(a.op == 'Extract' for a in body.args):
             first_ast = body.args[0].args[2]
@@ -350,6 +358,11 @@ def boolean_reverse_simplifier(body):
         if all(a.length == 8 for a in body.args):
             return body.make_like(body.op, body.args[::-1])
 
+    if body.op == 'Concat':
+        if all(a.op == 'Reverse' or (a.op == 'BVV' and a.args[0] == 0) for a in body.args):
+            if all(a.length % 8 == 0 for a in body.args):
+                return body.make_like(body.op,reversed([a.args[0] if a.op == 'Reverse' else a for a in body.args]))
+
 def boolean_and_simplifier(*args):
     if len(args) == 1:
         return args[0]
@@ -477,6 +490,56 @@ def bitwise_sub_simplifier(a, b):
     elif a is b or (a == b).is_true():
         return ast.all_operations.BVV(0, a.size())
 
+# recognize b-bit z=signedmax(q,r) from this idiom:
+# s=q-r;t=q^r;u=s^q;v=u&t;w=v^s;x=rshift(w,b-1);y=x&t;z=q^y
+# and recognize b-bit z=signedmin(q,r) from this idiom:
+# s=r-q;t=q^r;u=s^r;v=u&t;w=v^s;x=rshift(w,b-1);y=x&t;z=q^y
+def bitwise_xor_simplifier_minmax(a,b):
+    q,y = a,b
+    if y.op != '__and__':
+        q,y = b,a
+        if y.op != '__and__': return
+
+    x,t = y.args
+    if t.op != '__xor__':
+        t,x = y.args
+        if t.op != '__xor__': return
+
+    if x.op != '__rshift__': return
+    w,dist = x.args
+
+    bits = a.size()
+    if dist is not ast.all_operations.BVV(bits - 1,bits): return
+    if w.op != '__xor__': return
+
+    v,s = w.args
+    if s.op != '__sub__':
+        s,v = w.args
+        if s.op != '__sub__': return
+
+    if v.op != '__and__': return
+    u,t2 = v.args
+    if t2 is not t:
+        t2,u = v.args
+        if t2 is not t: return
+
+    if u.op != '__xor__': return
+
+    q2,r = t.args
+    if q2 is not q:
+        r,q2 = t.args
+        if q2 is not q: return
+
+    if (u.args[0] is s and u.args[1] is q) or (u.args[0] is q and u.args[1] is s):
+        if not (s.args[0] is q and s.args[1] is r): return
+        cond = ast.all_operations.SLE(q,r)
+        return ast.all_operations.If(cond,r,q)
+
+    if (u.args[0] is s and u.args[1] is r) or (u.args[0] is r and u.args[1] is s):
+        if not (s.args[0] is r and s.args[1] is q): return
+        cond = ast.all_operations.SLE(q,r)
+        return ast.all_operations.If(cond,q,r)
+
 def bitwise_xor_simplifier(a, b):
     if a is ast.all_operations.BVV(0, a.size()):
         return b
@@ -485,6 +548,14 @@ def bitwise_xor_simplifier(a, b):
     elif a is b or (a == b).is_true():
         return ast.all_operations.BVV(0, a.size())
 
+    result = bitwise_xor_simplifier_minmax(a,b)
+    if result is not None: return result
+
+    if a.op == 'Concat' and b.op == 'Concat':
+        if len(a.args) == len(b.args):
+            if all(x.size() == y.size() for x,y in zip(a.args,b.args)):
+                return ast.all_operations.Concat(*[x ^ y for x,y in zip(a.args,b.args)])
+
     def _flattening_filter(args):
         # since a ^ a == 0, we can safely remove those from args
         # this procedure is done carefully in order to keep the ordering of arguments
@@ -520,6 +591,11 @@ def bitwise_and_simplifier(a, b):
     elif a is b:
         return a
 
+    if a.op == 'Concat' and b.op == 'Concat':
+        if len(a.args) == len(b.args):
+            if all(x.size() == y.size() for x,y in zip(a.args,b.args)):
+                return ast.all_operations.Concat(*[x & y for x,y in zip(a.args,b.args)])
+
     def _flattening_filter(args):
         # a & a == a
         return tuple(OrderedSet(args))
@@ -583,6 +659,14 @@ def extract_simplifier(high, low, val):
     if (val.op == 'SignExt' or val.op == 'ZeroExt') and low == 0 and high + 1 == val.args[1].size():
         return val.args[1]
 
+    # (SignExt(n,v)>>s)[b-1:0] => v>>s if v has b bits
+    # XXX: do rshift semantics guarantee that shift distance is in range?
+    if val.op == '__rshift__':
+        if val.args[0].op == 'SignExt':
+            bits = val.args[0].args[1].size()
+            if low == 0 and high == bits - 1 and val.args[0].args[0] + bits < 2**(bits - 1):
+                return val.args[0].args[1].make_like(val.op,[val.args[0].args[1],val.args[1][bits-1:0]])
+
     if val.op == 'ZeroExt':
         extending_bits = val.args[0]
         if extending_bits == 0: