[PATCH 9/9] rs6000: Rework vector integer comparison in rs6000_emit_vector_compare - p5

[Kewen Lin <linkw@linux.ibm.com>]

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 5, it's to refactor all the handlings of vector
integer comparison to make it neat.  This patch doesn't
introduce any functionality change.

gcc/ChangeLog:

	* config/rs6000/rs6000.cc (rs6000_emit_vector_compare): Refactor the
	handlings of vector integer comparison.
---
 gcc/config/rs6000/rs6000.cc | 68 ++++++++++++++++++++++++-------------
 1 file changed, 44 insertions(+), 24 deletions(-)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index a3645e321a7..b694080840a 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -15662,34 +15662,54 @@ rs6000_emit_vector_compare (enum rtx_code rcode,
       return mask;
     }
 
-  /* For any of vector integer comparison operators for which we
-     have direct hardware instructions, just emit it directly
-     here.  */
-  if (rcode == EQ || rcode == GT || rcode == GTU)
-    emit_insn (gen_rtx_SET (mask, gen_rtx_fmt_ee (rcode, dmode, op0, op1)));
-  else if (rcode == LT || rcode == LTU)
+  bool swap_operands = false;
+  bool need_invert = false;
+  enum rtx_code code = rcode;
+
+  switch (rcode)
     {
+    case EQ:
+    case GT:
+    case GTU:
+      /* Emit directly with native hardware insn.  */
+      break;
+    case LT:
+    case 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)));
+      code = swap_condition (rcode);
+      swap_operands = true;
+      break;
+    case NE:
+    case LE:
+    case LEU:
+      /* ne(a,b) = ~eq(a,b); le{,u}(a,b) = ~gt{,u}(a,b)  */
+      code = reverse_condition (rcode);
+      need_invert = true;
+      break;
+    case GE:
+      /* ge(a,b) = ~gt(b,a)  */
+      code = GT;
+      swap_operands = true;
+      need_invert = true;
+      break;
+    case GEU:
+      /* geu(a,b) = ~gtu(b,a)  */
+      code = GTU;
+      swap_operands = true;
+      need_invert = true;
+      break;
+    default:
+      gcc_unreachable ();
+      break;
     }
-  else if (rcode == NE || rcode == LE || rcode == LEU)
+
+  if (swap_operands)
+    std::swap (op0, op1);
+
+  emit_insn (gen_rtx_SET (mask, gen_rtx_fmt_ee (code, dmode, op0, op1)));
+
+  if (need_invert)
     {
-      /* ne(a,b) = ~eq(a,b); le{,u}(a,b) = ~gt{,u}(a,b)  */
-      enum rtx_code code = reverse_condition (rcode);
-      mask = gen_reg_rtx (dmode);
-      emit_insn (gen_rtx_SET (mask, gen_rtx_fmt_ee (code, dmode, op0, op1)));
-      enum insn_code nor_code = optab_handler (one_cmpl_optab, dmode);
-      gcc_assert (nor_code != CODE_FOR_nothing);
-      emit_insn (GEN_FCN (nor_code) (mask, mask));
-    } else {
-      /* ge{,u}(a,b) = ~gt{,u}(b,a)  */
-      gcc_assert (rcode == GE || rcode == GEU);
-      enum rtx_code code = rcode == GE ? GT : GTU;
-      mask = gen_reg_rtx (dmode);
-      emit_insn (gen_rtx_SET (mask, gen_rtx_fmt_ee (code, dmode, op0, op1)));
       enum insn_code nor_code = optab_handler (one_cmpl_optab, dmode);
       gcc_assert (nor_code != CODE_FOR_nothing);
       emit_insn (GEN_FCN (nor_code) (mask, mask));
-- 
2.27.0