target/alpha: optimize gen_cvtlq() using deposit op

Suggested-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170718045540.16322-10-f4bug@amsat.org>
Signed-off-by: NRichard Henderson <rth@twiddle.net>

target/alpha/translate.c

@@ -783,11 +783,9 @@ static void gen_cvtlq(TCGv vc, TCGv vb)
 
     /* The arithmetic right shift here, plus the sign-extended mask below
        yields a sign-extended result without an explicit ext32s_i64.  */
-    tcg_gen_sari_i64(tmp, vb, 32);
-    tcg_gen_shri_i64(vc, vb, 29);
-    tcg_gen_andi_i64(tmp, tmp, (int32_t)0xc0000000);
-    tcg_gen_andi_i64(vc, vc, 0x3fffffff);
-    tcg_gen_or_i64(vc, vc, tmp);
+    tcg_gen_shri_i64(tmp, vb, 29);
+    tcg_gen_sari_i64(vc, vb, 32);
+    tcg_gen_deposit_i64(vc, vc, tmp, 0, 30);
 
     tcg_temp_free(tmp);
 }