diff --git a/target-arm/translate.c b/target-arm/translate.c
index bfe0f21353..711676ff7d 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -221,8 +221,8 @@ static void store_reg(DisasContext *s, int reg, TCGv var)
 #define gen_op_rorl_T1_im(im) tcg_gen_rori_i32(cpu_T[1], cpu_T[1], im)
 
 /* Value extensions.  */
-#define gen_uxtb(var) tcg_gen_andi_i32(var, var, 0xff)
-#define gen_uxth(var) tcg_gen_andi_i32(var, var, 0xffff)
+#define gen_uxtb(var) tcg_gen_ext8u_i32(var, var)
+#define gen_uxth(var) tcg_gen_ext16u_i32(var, var)
 #define gen_sxtb(var) tcg_gen_ext8s_i32(var, var)
 #define gen_sxth(var) tcg_gen_ext16s_i32(var, var)
 
@@ -1446,7 +1446,7 @@ static void gen_op_iwmmxt_setpsr_nz(void)
 static inline void gen_op_iwmmxt_addl_M0_wRn(int rn)
 {
     iwmmxt_load_reg(cpu_V1, rn);
-    tcg_gen_andi_i64(cpu_V1, cpu_V1, 0xffffffffu);
+    tcg_gen_ext32u_i64(cpu_V1, cpu_V1);
     tcg_gen_add_i64(cpu_M0, cpu_M0, cpu_V1);
 }
 
@@ -2704,7 +2704,7 @@ static void gen_neon_dup_u8(TCGv var, int shift)
     TCGv tmp = new_tmp();
     if (shift)
         tcg_gen_shri_i32(var, var, shift);
-    tcg_gen_andi_i32(var, var, 0xff);
+    tcg_gen_ext8u_i32(var, var);
     tcg_gen_shli_i32(tmp, var, 8);
     tcg_gen_or_i32(var, var, tmp);
     tcg_gen_shli_i32(tmp, var, 16);
@@ -2715,7 +2715,7 @@ static void gen_neon_dup_u8(TCGv var, int shift)
 static void gen_neon_dup_low16(TCGv var)
 {
     TCGv tmp = new_tmp();
-    tcg_gen_andi_i32(var, var, 0xffff);
+    tcg_gen_ext16u_i32(var, var);
     tcg_gen_shli_i32(tmp, var, 16);
     tcg_gen_or_i32(var, var, tmp);
     dead_tmp(tmp);
@@ -5862,7 +5862,7 @@ static void disas_arm_insn(CPUState * env, DisasContext *s)
             } else {
                 /* MOVT */
                 tmp = load_reg(s, rd);
-                tcg_gen_andi_i32(tmp, tmp, 0xffff);
+                tcg_gen_ext16u_i32(tmp, tmp);
                 tcg_gen_ori_i32(tmp, tmp, val << 16);
             }
             store_reg(s, rd, tmp);
@@ -6378,10 +6378,10 @@ static void disas_arm_insn(CPUState * env, DisasContext *s)
                         if (insn & (1 << 6)) {
                             /* pkhtb */
                             tcg_gen_andi_i32(tmp, tmp, 0xffff0000);
-                            tcg_gen_andi_i32(tmp2, tmp2, 0xffff);
+                            tcg_gen_ext16u_i32(tmp2, tmp2);
                         } else {
                             /* pkhbt */
-                            tcg_gen_andi_i32(tmp, tmp, 0xffff);
+                            tcg_gen_ext16u_i32(tmp, tmp);
                             tcg_gen_andi_i32(tmp2, tmp2, 0xffff0000);
                         }
                         tcg_gen_or_i32(tmp, tmp, tmp2);
@@ -7700,7 +7700,7 @@ static int disas_thumb2_insn(CPUState *env, DisasContext *s, uint16_t insn_hw1)
                         if (insn & (1 << 23)) {
                             /* movt */
                             tmp = load_reg(s, rd);
-                            tcg_gen_andi_i32(tmp, tmp, 0xffff);
+                            tcg_gen_ext16u_i32(tmp, tmp);
                             tcg_gen_ori_i32(tmp, tmp, imm << 16);
                         } else {
                             /* movw */
diff --git a/target-cris/translate.c b/target-cris/translate.c
index 72eb48cdf9..89a0533857 100644
--- a/target-cris/translate.c
+++ b/target-cris/translate.c
@@ -1165,11 +1165,10 @@ static inline void t_gen_sext(TCGv d, TCGv s, int size)
 
 static inline void t_gen_zext(TCGv d, TCGv s, int size)
 {
-	/* TCG-FIXME: this is not optimal. Many archs have fast zext insns.  */
 	if (size == 1)
-		tcg_gen_andi_i32(d, s, 0xff);
+		tcg_gen_ext8u_i32(d, s);
 	else if (size == 2)
-		tcg_gen_andi_i32(d, s, 0xffff);
+		tcg_gen_ext16u_i32(d, s);
 	else
 		tcg_gen_mov_tl(d, s);
 }
diff --git a/tcg/README b/tcg/README
index c27c5abed9..c47d3b07ac 100644
--- a/tcg/README
+++ b/tcg/README
@@ -260,10 +260,13 @@ t0 = t1
 Move t1 to t0 (both operands must have the same type).
 
 * ext8s_i32/i64 t0, t1
+ext8u_i32/i64 t0, t1
 ext16s_i32/i64 t0, t1
+ext16u_i32/i64 t0, t1
 ext32s_i64 t0, t1
+ext32u_i64 t0, t1
 
-8, 16 or 32 bit sign extension (both operands must have the same type)
+8, 16 or 32 bit sign/zero extension (both operands must have the same type)
 
 * bswap16_i32 t0, t1
 
diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index 1daf130f17..8ab9536603 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -980,6 +980,18 @@ static inline void tcg_gen_ext16s_i32(TCGv ret, TCGv arg)
 #endif
 }
 
+/* These are currently just for convenience.
+   We assume a target will recognise these automatically .  */
+static inline void tcg_gen_ext8u_i32(TCGv ret, TCGv arg)
+{
+    tcg_gen_andi_i32(ret, arg, 0xffu);
+}
+
+static inline void tcg_gen_ext16u_i32(TCGv ret, TCGv arg)
+{
+    tcg_gen_andi_i32(ret, arg, 0xffffu);
+}
+
 /* Note: we assume the two high bytes are set to zero */
 static inline void tcg_gen_bswap16_i32(TCGv ret, TCGv arg)
 {
@@ -1040,6 +1052,24 @@ static inline void tcg_gen_ext32s_i64(TCGv ret, TCGv arg)
     tcg_gen_sari_i32(TCGV_HIGH(ret), ret, 31);
 }
 
+static inline void tcg_gen_ext8u_i64(TCGv ret, TCGv arg)
+{
+    tcg_gen_ext8u_i32(ret, arg);
+    tcg_gen_movi_i32(TCGV_HIGH(ret), 0);
+}
+
+static inline void tcg_gen_ext16u_i64(TCGv ret, TCGv arg)
+{
+    tcg_gen_ext16u_i32(ret, arg);
+    tcg_gen_movi_i32(TCGV_HIGH(ret), 0);
+}
+
+static inline void tcg_gen_ext32u_i64(TCGv ret, TCGv arg)
+{
+    tcg_gen_mov_i32(ret, arg);
+    tcg_gen_movi_i32(TCGV_HIGH(ret), 0);
+}
+
 static inline void tcg_gen_trunc_i64_i32(TCGv ret, TCGv arg)
 {
     tcg_gen_mov_i32(ret, arg);
@@ -1100,6 +1130,21 @@ static inline void tcg_gen_ext32s_i64(TCGv ret, TCGv arg)
 #endif
 }
 
+static inline void tcg_gen_ext8u_i64(TCGv ret, TCGv arg)
+{
+    tcg_gen_andi_i64(ret, arg, 0xffu);
+}
+
+static inline void tcg_gen_ext16u_i64(TCGv ret, TCGv arg)
+{
+    tcg_gen_andi_i64(ret, arg, 0xffffu);
+}
+
+static inline void tcg_gen_ext32u_i64(TCGv ret, TCGv arg)
+{
+    tcg_gen_andi_i64(ret, arg, 0xffffffffu);
+}
+
 /* Note: we assume the target supports move between 32 and 64 bit
    registers.  This will probably break MIPS64 targets.  */
 static inline void tcg_gen_trunc_i64_i32(TCGv ret, TCGv arg)
@@ -1111,7 +1156,7 @@ static inline void tcg_gen_trunc_i64_i32(TCGv ret, TCGv arg)
    registers */
 static inline void tcg_gen_extu_i32_i64(TCGv ret, TCGv arg)
 {
-    tcg_gen_andi_i64(ret, arg, 0xffffffff);
+    tcg_gen_andi_i64(ret, arg, 0xffffffffu);
 }
 
 /* Note: we assume the target supports move between 32 and 64 bit