[04/10] mips: Support even-odd permutation for Loongson V8QImode.

diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index a1f06d4..0ac1096 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -16391,6 +16391,63 @@  expand_vselect_vconcat (rtx target, rtx op0, rtx op1,
   return expand_vselect (target, x, perm, nelt);
 }
 
+/* Recognize patterns for even-odd extraction.  */
+
+static bool
+mips_expand_vpc_loongson_even_odd (struct expand_vec_perm_d *d)
+{
+  unsigned i, odd, nelt = d->nelt;
+  rtx t0, t1, t2, t3;
+
+  if (!(TARGET_HARD_FLOAT && TARGET_LOONGSON_VECTORS))
+    return false;
+  /* Even-odd for V2SI/V2SFmode is matched by interleave directly.  */
+  if (nelt < 4)
+    return false;
+
+  odd = d->perm[0];
+  if (odd > 1)
+    return false;
+  for (i = 1; i < nelt; ++i)
+    if (d->perm[i] != i * 2 + odd)
+      return false;
+
+  if (d->testing_p)
+    return true;
+
+  /* We need 2*log2(N)-1 operations to achieve odd/even with interleave. */
+  t0 = gen_reg_rtx (d->vmode);
+  t1 = gen_reg_rtx (d->vmode);
+  switch (d->vmode)
+    {
+    case V4HImode:
+      emit_insn (gen_loongson_punpckhhw (t0, d->op0, d->op1));
+      emit_insn (gen_loongson_punpcklhw (t1, d->op0, d->op1));
+      if (odd)
+	emit_insn (gen_loongson_punpckhhw (d->target, t1, t0));
+      else
+	emit_insn (gen_loongson_punpcklhw (d->target, t1, t0));
+      break;
+
+    case V8QImode:
+      t2 = gen_reg_rtx (d->vmode);
+      t3 = gen_reg_rtx (d->vmode);
+      emit_insn (gen_loongson_punpckhbh (t0, d->op0, d->op1));
+      emit_insn (gen_loongson_punpcklbh (t1, d->op0, d->op1));
+      emit_insn (gen_loongson_punpckhbh (t2, t1, t0));
+      emit_insn (gen_loongson_punpcklbh (t3, t1, t0));
+      if (odd)
+	emit_insn (gen_loongson_punpckhbh (d->target, t3, t2));
+      else
+	emit_insn (gen_loongson_punpcklbh (d->target, t3, t2));
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+  return true;
+}
+
 /* Recognize patterns for the Loongson PSHUFH instruction.  */
 
 static bool
@@ -16445,6 +16502,8 @@  mips_expand_vec_perm_const_1 (struct expand_vec_perm_d *d)
 	return true;
     }
 
+  if (mips_expand_vpc_loongson_even_odd (d))
+    return true;
   if (mips_expand_vpc_loongson_pshufh (d))
     return true;
   return false;