diff --git a/src/ast/rewriter/bit_blaster/bit_blaster.h b/src/ast/rewriter/bit_blaster/bit_blaster.h
index 4feeb6f5a..6221eeaf9 100644
--- a/src/ast/rewriter/bit_blaster/bit_blaster.h
+++ b/src/ast/rewriter/bit_blaster/bit_blaster.h
@@ -20,8 +20,8 @@ Revision History:
 #define BIT_BLASTER_H_
 
 #include"bool_rewriter.h"
-#include"bit_blaster/bit_blaster_params.h"
-#include"bit_blaster/bit_blaster_tpl.h"
+#include"bit_blaster_params.h"
+#include"bit_blaster_tpl.h"
 #include"bv_decl_plugin.h"
 #include"rational.h"
 
diff --git a/src/ast/rewriter/bv_rewriter.cpp b/src/ast/rewriter/bv_rewriter.cpp
index d876dc8cb..66546f2f2 100644
--- a/src/ast/rewriter/bv_rewriter.cpp
+++ b/src/ast/rewriter/bv_rewriter.cpp
@@ -20,7 +20,6 @@ Notes:
 #include"bv_rewriter_params.hpp"
 #include"poly_rewriter_def.h"
 #include"ast_smt2_pp.h"
-#include"bit_blaster/bit_blaster.h"
 
 
 void bv_rewriter::updt_local_params(params_ref const & _p) {
@@ -190,15 +189,12 @@ br_status bv_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr * cons
         return mk_bv_comp(args[0], args[1], result);
     case OP_MKBV:
         return mk_mkbv(num_args, args, result);
-    case OP_BUMUL_NO_OVFL:
-        SASSERT(num_args == 2);
-        return mk_bv_umul_no_ovfl(args[0], args[1], result);
     case OP_BSMUL_NO_OVFL:
-        SASSERT(num_args == 2);
-        return mk_bv_smul_no_ovfl(args[0], args[1], result);        
-    case OP_BSMUL_NO_UDFL: 
-        SASSERT(num_args == 2);
-        return mk_bv_smul_no_udfl(args[0], args[1], result);        
+        return mk_bvsmul_no_overflow(num_args, args, result);
+    case OP_BUMUL_NO_OVFL:
+        return mk_bvumul_no_overflow(num_args, args, result);
+    case OP_BSMUL_NO_UDFL:
+        return mk_bvsmul_no_underflow(num_args, args, result);
     default:
         return BR_FAILED;
     }
@@ -1110,90 +1106,6 @@ br_status bv_rewriter::mk_concat(unsigned num_args, expr * const * args, expr_re
         return BR_DONE;
 }
 
-br_status bv_rewriter::mk_bv_umul_no_ovfl(expr * arg1, expr * arg2, expr_ref& result) {
-    rational val1, val2;
-    unsigned bv_size;
-    bool is_num1 = is_numeral(arg1, val1, bv_size);
-    bool is_num2 = is_numeral(arg2, val2, bv_size);
-    if (is_num1 && (val1.is_zero() || val1.is_one())) {
-        result = m().mk_true();
-        return BR_DONE;
-    }
-    if (is_num2 && (val2.is_zero() || val2.is_one())) {
-        result = m().mk_true();
-        return BR_DONE;
-    }
-    if (is_num1 && is_num2) {
-        SASSERT(!val1.is_neg());
-        SASSERT(!val2.is_neg());
-        rational r = val1 * val2;
-        result = m().mk_bool_val(r < rational(2).expt(bv_size));
-        return BR_DONE;
-    }
-    return BR_FAILED;
-}
-
-br_status bv_rewriter::mk_bv_smul_no_ovfl(expr * arg1, expr * arg2, expr_ref& result) {
-    rational val1, val2;
-    unsigned bv_size;
-    bool is_num1 = is_numeral(arg1, val1, bv_size);
-    bool is_num2 = is_numeral(arg2, val2, bv_size);
-    if (is_num1 && (val1.is_zero() || val1.is_one())) {
-        result = m().mk_true();
-        return BR_DONE;
-    }
-    if (is_num2 && (val2.is_zero() || val2.is_one())) {
-        result = m().mk_true();
-        return BR_DONE;
-    }
-    if (is_num1 && is_num2) {
-        bit_blaster_params params;
-        bit_blaster blaster(m(), params);
-        SASSERT(!val1.is_neg());
-        SASSERT(!val2.is_neg());
-        expr_ref_vector bits1(m()), bits2(m());
-        for (unsigned i = 0; i < bv_size; ++i) {
-            bits1.push_back(m().mk_bool_val(!val1.is_even()));
-            bits2.push_back(m().mk_bool_val(!val2.is_even()));
-            val1 = div(val1, rational(2));
-            val2 = div(val2, rational(2));
-        }
-        blaster.mk_smul_no_overflow(bits1.size(), bits1.c_ptr(), bits2.c_ptr(), result);
-        return BR_DONE;
-    }
-    return BR_FAILED;
-}
-
-br_status bv_rewriter::mk_bv_smul_no_udfl(expr * arg1, expr * arg2, expr_ref& result) {
-    rational val1, val2;
-    unsigned bv_size;
-    bool is_num1 = is_numeral(arg1, val1, bv_size);
-    bool is_num2 = is_numeral(arg2, val2, bv_size);
-    if (is_num1 && (val1.is_zero() || val1.is_one())) {
-        result = m().mk_true();
-        return BR_DONE;
-    }
-    if (is_num2 && (val2.is_zero() || val2.is_one())) {
-        result = m().mk_true();
-        return BR_DONE;
-    }
-    if (is_num1 && is_num2) {
-        bit_blaster_params params;
-        bit_blaster blaster(m(), params);
-        SASSERT(!val1.is_neg());
-        SASSERT(!val2.is_neg());
-        expr_ref_vector bits1(m()), bits2(m());
-        for (unsigned i = 0; i < bv_size; ++i) {
-            bits1.push_back(m().mk_bool_val(!val1.is_even()));
-            bits2.push_back(m().mk_bool_val(!val2.is_even()));
-            val1 = div(val1, rational(2));
-            val2 = div(val2, rational(2));
-        }
-        blaster.mk_smul_no_underflow(bits1.size(), bits1.c_ptr(), bits2.c_ptr(), result);
-        return BR_DONE;
-    }
-    return BR_FAILED;
-}
 
 
 br_status bv_rewriter::mk_zero_extend(unsigned n, expr * arg, expr_ref & result) {
@@ -2282,6 +2194,88 @@ br_status bv_rewriter::mk_mkbv(unsigned num, expr * const * args, expr_ref & res
     return BR_FAILED;
 }
 
+br_status bv_rewriter::mk_bvsmul_no_overflow(unsigned num, expr * const * args, expr_ref & result) {
+    SASSERT(num == 2);
+    unsigned bv_sz;
+    rational a0_val, a1_val;
+
+    bool is_num1 = is_numeral(args[0], a0_val, bv_sz);
+    bool is_num2 = is_numeral(args[1], a1_val, bv_sz);
+    if (is_num1 && (a0_val.is_zero() || a0_val.is_one())) {
+        result = m().mk_true();
+        return BR_DONE;
+    }
+    if (is_num2 && (a1_val.is_zero() || a1_val.is_one())) {
+        result = m().mk_true();
+        return BR_DONE;
+    }
+
+    if (is_num1 && is_num2) {
+        rational mr = a0_val * a1_val;
+        rational lim = rational::power_of_two(bv_sz-1);
+        result = (mr < lim) ? m().mk_true() : m().mk_false();
+        return BR_DONE;
+    }
+
+    return BR_FAILED;
+}
+
+br_status bv_rewriter::mk_bvumul_no_overflow(unsigned num, expr * const * args, expr_ref & result) {
+    SASSERT(num == 2);
+    unsigned bv_sz;
+    rational a0_val, a1_val;
+
+    bool is_num1 = is_numeral(args[0], a0_val, bv_sz);
+    bool is_num2 = is_numeral(args[1], a1_val, bv_sz);
+    if (is_num1 && (a0_val.is_zero() || a0_val.is_one())) {
+        result = m().mk_true();
+        return BR_DONE;
+    }
+    if (is_num2 && (a1_val.is_zero() || a1_val.is_one())) {
+        result = m().mk_true();
+        return BR_DONE;
+    }
+
+    if (is_num1 && is_num2) {
+        rational mr = a0_val * a1_val;
+        rational lim = rational::power_of_two(bv_sz);
+        result = (mr < lim) ? m().mk_true() : m().mk_false();
+        return BR_DONE;
+    }
+
+    return BR_FAILED;
+}
+
+br_status bv_rewriter::mk_bvsmul_no_underflow(unsigned num, expr * const * args, expr_ref & result) {
+    SASSERT(num == 2);
+    unsigned bv_sz;
+    rational a0_val, a1_val;
+
+    bool is_num1 = is_numeral(args[0], a0_val, bv_sz);
+    bool is_num2 = is_numeral(args[1], a1_val, bv_sz);
+    if (is_num1 && (a0_val.is_zero() || a0_val.is_one())) {
+        result = m().mk_true();
+        return BR_DONE;
+    }
+    if (is_num2 && (a1_val.is_zero() || a1_val.is_one())) {
+        result = m().mk_true();
+        return BR_DONE;
+    }
+
+    if (is_num1 && is_num2) {
+        rational ul = rational::power_of_two(bv_sz);
+        rational lim = rational::power_of_two(bv_sz-1);
+        if (a0_val >= lim) a0_val -= ul;
+        if (a1_val >= lim) a1_val -= ul;        
+        rational mr = a0_val * a1_val;
+        rational neg_lim = -lim;
+        TRACE("bv_rewriter_bvsmul_no_underflow", tout << "a0:" << a0_val << " a1:" << a1_val << " mr:" << mr << " neg_lim:" << neg_lim << std::endl;);
+        result = (mr >= neg_lim) ? m().mk_true() : m().mk_false();
+        return BR_DONE;
+    }
+
+    return BR_FAILED;
+}
+
 
 template class poly_rewriter<bv_rewriter_core>;
-
diff --git a/src/ast/rewriter/bv_rewriter.h b/src/ast/rewriter/bv_rewriter.h
index 0b449d006..a8db05013 100644
--- a/src/ast/rewriter/bv_rewriter.h
+++ b/src/ast/rewriter/bv_rewriter.h
@@ -114,9 +114,6 @@ class bv_rewriter : public poly_rewriter<bv_rewriter_core> {
     br_status mk_bv_srem_i(expr * arg1, expr * arg2, expr_ref & result) { return mk_bv_srem_core(arg1, arg2, true, result); }
     br_status mk_bv_urem_i(expr * arg1, expr * arg2, expr_ref & result) { return mk_bv_urem_core(arg1, arg2, true, result); }
     br_status mk_bv_smod_i(expr * arg1, expr * arg2, expr_ref & result) { return mk_bv_smod_core(arg1, arg2, true, result); }
-    br_status mk_bv_umul_no_ovfl(expr * arg1, expr * arg2, expr_ref& result);
-    br_status mk_bv_smul_no_ovfl(expr * arg1, expr * arg2, expr_ref& result);
-    br_status mk_bv_smul_no_udfl(expr * arg1, expr * arg2, expr_ref& result);
     br_status mk_int2bv(unsigned bv_size, expr * arg, expr_ref & result);
     br_status mk_bv2int(expr * arg, expr_ref & result);
     br_status mk_bv_redor(expr * arg, expr_ref & result);
@@ -126,6 +123,9 @@ class bv_rewriter : public poly_rewriter<bv_rewriter_core> {
     br_status mk_blast_eq_value(expr * lhs, expr * rhs, expr_ref & result);
     br_status mk_eq_concat(expr * lhs, expr * rhs, expr_ref & result);
     br_status mk_mkbv(unsigned num, expr * const * args, expr_ref & result);
+    br_status mk_bvsmul_no_overflow(unsigned num, expr * const * args, expr_ref & result);
+    br_status mk_bvumul_no_overflow(unsigned num, expr * const * args, expr_ref & result);
+    br_status mk_bvsmul_no_underflow(unsigned num, expr * const * args, expr_ref & result);
     bool is_minus_one_times_t(expr * arg);
     void mk_t1_add_t2_eq_c(expr * t1, expr * t2, expr * c, expr_ref & result);