tcg/ppc: Split out tcg_out_bswap64

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/ppc/tcg-target.c.inc

@@ -828,6 +828,39 @@ static void tcg_out_bswap32(TCGContext *s, TCGReg dst, TCGReg src)
     tcg_out_mov(s, TCG_TYPE_REG, dst, tmp);
 }
 
+static void tcg_out_bswap64(TCGContext *s, TCGReg dst, TCGReg src)
+{
+    TCGReg t0 = dst == src ? TCG_REG_R0 : dst;
+    TCGReg t1 = dst == src ? dst : TCG_REG_R0;
+
+    /*
+     * In the following,
+     *   dep(a, b, m) -> (a & ~m) | (b & m)
+     *
+     * Begin with:                              src = abcdefgh
+     */
+    /* t0 = rol32(src, 8) & 0xffffffff              = 0000fghe */
+    tcg_out_rlw(s, RLWINM, t0, src, 8, 0, 31);
+    /* t0 = dep(t0, rol32(src, 24), 0xff000000)     = 0000hghe */
+    tcg_out_rlw(s, RLWIMI, t0, src, 24, 0, 7);
+    /* t0 = dep(t0, rol32(src, 24), 0x0000ff00)     = 0000hgfe */
+    tcg_out_rlw(s, RLWIMI, t0, src, 24, 16, 23);
+
+    /* t0 = rol64(t0, 32)                           = hgfe0000 */
+    tcg_out_rld(s, RLDICL, t0, t0, 32, 0);
+    /* t1 = rol64(src, 32)                          = efghabcd */
+    tcg_out_rld(s, RLDICL, t1, src, 32, 0);
+
+    /* t0 = dep(t0, rol32(t1, 24), 0xffffffff)      = hgfebcda */
+    tcg_out_rlw(s, RLWIMI, t0, t1, 8, 0, 31);
+    /* t0 = dep(t0, rol32(t1, 24), 0xff000000)      = hgfedcda */
+    tcg_out_rlw(s, RLWIMI, t0, t1, 24, 0, 7);
+    /* t0 = dep(t0, rol32(t1, 24), 0x0000ff00)      = hgfedcba */
+    tcg_out_rlw(s, RLWIMI, t0, t1, 24, 16, 23);
+
+    tcg_out_mov(s, TCG_TYPE_REG, dst, t0);
+}
+
 /* Emit a move into ret of arg, if it can be done in one insn.  */
 static bool tcg_out_movi_one(TCGContext *s, TCGReg ret, tcg_target_long arg)
 {
@@ -2824,37 +2857,8 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc,
     case INDEX_op_bswap32_i64:
         tcg_out_bswap32(s, args[0], args[1]);
         break;
-
     case INDEX_op_bswap64_i64:
-        a0 = args[0], a1 = args[1], a2 = TCG_REG_R0;
-        if (a0 == a1) {
-            a0 = TCG_REG_R0;
-            a2 = a1;
-        }
-
-        /* a1 = # abcd efgh */
-        /* a0 = rl32(a1, 8) # 0000 fghe */
-        tcg_out_rlw(s, RLWINM, a0, a1, 8, 0, 31);
-        /* a0 = dep(a0, rl32(a1, 24), 0xff000000) # 0000 hghe */
-        tcg_out_rlw(s, RLWIMI, a0, a1, 24, 0, 7);
-        /* a0 = dep(a0, rl32(a1, 24), 0x0000ff00) # 0000 hgfe */
-        tcg_out_rlw(s, RLWIMI, a0, a1, 24, 16, 23);
-
-        /* a0 = rl64(a0, 32) # hgfe 0000 */
-        /* a2 = rl64(a1, 32) # efgh abcd */
-        tcg_out_rld(s, RLDICL, a0, a0, 32, 0);
-        tcg_out_rld(s, RLDICL, a2, a1, 32, 0);
-
-        /* a0 = dep(a0, rl32(a2, 8), 0xffffffff)  # hgfe bcda */
-        tcg_out_rlw(s, RLWIMI, a0, a2, 8, 0, 31);
-        /* a0 = dep(a0, rl32(a2, 24), 0xff000000) # hgfe dcda */
-        tcg_out_rlw(s, RLWIMI, a0, a2, 24, 0, 7);
-        /* a0 = dep(a0, rl32(a2, 24), 0x0000ff00) # hgfe dcba */
-        tcg_out_rlw(s, RLWIMI, a0, a2, 24, 16, 23);
-
-        if (a0 == 0) {
-            tcg_out_mov(s, TCG_TYPE_REG, args[0], a0);
-        }
+        tcg_out_bswap64(s, args[0], args[1]);
         break;
 
     case INDEX_op_deposit_i32: