rs6000: Rework vector integer comparison in rs6000_emit_vector_compare - p2

The current handlings in rs6000_emit_vector_compare is a bit
complicated to me, especially after we emit vector float
comparison insn with the given code directly.  So it's better
to refactor the handlings of vector integer comparison here.

This is part 2, it's to refactor the handlings on LT and LTU.
This patch doesn't introduce any functionality change.

gcc/ChangeLog:

	* config/rs6000/rs6000.cc (rs6000_emit_vector_compare): Refine the
	handlings for operators LT and LTU.

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 44477657bc298de420c39d7dfa95f6f65f2d1844..718d65951e7f3f7961c3e812858237652ba77c2c 100644 (file)
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -16042,22 +16042,18 @@ rs6000_emit_vector_compare (enum rtx_code rcode,
       emit_insn (gen_rtx_SET (mask, gen_rtx_fmt_ee (rcode, dmode, op0, op1)));
       return mask;
     }
-
-  bool swap_operands = false;
-  bool try_again = false;
+  else if (rcode == LT || rcode == LTU)
+    {
+      /* lt{,u}(a,b) = gt{,u}(b,a)  */
+      enum rtx_code code = swap_condition (rcode);
+      std::swap (op0, op1);
+      mask = gen_reg_rtx (dmode);
+      emit_insn (gen_rtx_SET (mask, gen_rtx_fmt_ee (code, dmode, op0, op1)));
+      return mask;
+    }
 
   switch (rcode)
     {
-    case LT:
-      rcode = GT;
-      swap_operands = true;
-      try_again = true;
-      break;
-    case LTU:
-      rcode = GTU;
-      swap_operands = true;
-      try_again = true;
-      break;
     case NE:
       /* Invert condition and try again.
         e.g., A != B becomes ~(A==B).  */
@@ -16131,16 +16127,6 @@ rs6000_emit_vector_compare (enum rtx_code rcode,
       return NULL_RTX;
     }
 
-  if (try_again)
-    {
-      if (swap_operands)
-       std::swap (op0, op1);
-
-      mask = rs6000_emit_vector_compare (rcode, op0, op1, dmode);
-      if (mask)
-       return mask;
-    }
-
   /* You only get two chances.  */
   return NULL_RTX;
 }