From c068896f7f10f82d96a986ceea0d69d8579e3932 Mon Sep 17 00:00:00 2001
From: Richard Henderson <rth@twiddle.net>
Date: Tue, 15 Apr 2014 22:20:57 -0700
Subject: [PATCH] tcg-mips: Simplify brcond

Use the same table to fold comparisons as with setcond.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/mips/tcg-target.c | 89 ++++++++++++++++++++-----------------------
 1 file changed, 42 insertions(+), 47 deletions(-)

diff --git a/tcg/mips/tcg-target.c b/tcg/mips/tcg-target.c
index 278925c6ff..c0a7a048ca 100644
--- a/tcg/mips/tcg-target.c
+++ b/tcg/mips/tcg-target.c
@@ -634,70 +634,65 @@ static void tcg_out_setcond(TCGContext *s, TCGCond cond, TCGReg ret,
      }
 }
 
-static void tcg_out_brcond(TCGContext *s, TCGCond cond, TCGArg arg1,
-                           TCGArg arg2, int label_index)
+static void tcg_out_brcond(TCGContext *s, TCGCond cond, TCGReg arg1,
+                           TCGReg arg2, int label_index)
 {
-    TCGLabel *l = &s->labels[label_index];
+    static const MIPSInsn b_zero[16] = {
+        [TCG_COND_LT] = OPC_BLTZ,
+        [TCG_COND_GT] = OPC_BGTZ,
+        [TCG_COND_LE] = OPC_BLEZ,
+        [TCG_COND_GE] = OPC_BGEZ,
+    };
+
+    TCGLabel *l;
+    MIPSInsn s_opc = OPC_SLTU;
+    MIPSInsn b_opc;
+    int cmp_map;
 
     switch (cond) {
     case TCG_COND_EQ:
-        tcg_out_opc_br(s, OPC_BEQ, arg1, arg2);
+        b_opc = OPC_BEQ;
         break;
     case TCG_COND_NE:
-        tcg_out_opc_br(s, OPC_BNE, arg1, arg2);
+        b_opc = OPC_BNE;
         break;
+
     case TCG_COND_LT:
-        if (arg2 == 0) {
-            tcg_out_opc_br(s, OPC_BLTZ, 0, arg1);
-        } else {
-            tcg_out_opc_reg(s, OPC_SLT, TCG_TMP0, arg1, arg2);
-            tcg_out_opc_br(s, OPC_BNE, TCG_TMP0, TCG_REG_ZERO);
-        }
-        break;
-    case TCG_COND_LTU:
-        tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP0, arg1, arg2);
-        tcg_out_opc_br(s, OPC_BNE, TCG_TMP0, TCG_REG_ZERO);
-        break;
+    case TCG_COND_GT:
+    case TCG_COND_LE:
     case TCG_COND_GE:
         if (arg2 == 0) {
-            tcg_out_opc_br(s, OPC_BGEZ, 0, arg1);
-        } else {
-            tcg_out_opc_reg(s, OPC_SLT, TCG_TMP0, arg1, arg2);
-            tcg_out_opc_br(s, OPC_BEQ, TCG_TMP0, TCG_REG_ZERO);
+            b_opc = b_zero[cond];
+            arg2 = arg1;
+            arg1 = 0;
+            break;
         }
-        break;
-    case TCG_COND_GEU:
-        tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP0, arg1, arg2);
-        tcg_out_opc_br(s, OPC_BEQ, TCG_TMP0, TCG_REG_ZERO);
-        break;
-    case TCG_COND_LE:
-        if (arg2 == 0) {
-            tcg_out_opc_br(s, OPC_BLEZ, 0, arg1);
-        } else {
-            tcg_out_opc_reg(s, OPC_SLT, TCG_TMP0, arg2, arg1);
-            tcg_out_opc_br(s, OPC_BEQ, TCG_TMP0, TCG_REG_ZERO);
-        }
-        break;
-    case TCG_COND_LEU:
-        tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP0, arg2, arg1);
-        tcg_out_opc_br(s, OPC_BEQ, TCG_TMP0, TCG_REG_ZERO);
-        break;
-    case TCG_COND_GT:
-        if (arg2 == 0) {
-            tcg_out_opc_br(s, OPC_BGTZ, 0, arg1);
-        } else {
-            tcg_out_opc_reg(s, OPC_SLT, TCG_TMP0, arg2, arg1);
-            tcg_out_opc_br(s, OPC_BNE, TCG_TMP0, TCG_REG_ZERO);
-        }
-        break;
+        s_opc = OPC_SLT;
+        /* FALLTHRU */
+
+    case TCG_COND_LTU:
     case TCG_COND_GTU:
-        tcg_out_opc_reg(s, OPC_SLTU, TCG_TMP0, arg2, arg1);
-        tcg_out_opc_br(s, OPC_BNE, TCG_TMP0, TCG_REG_ZERO);
+    case TCG_COND_LEU:
+    case TCG_COND_GEU:
+        cmp_map = mips_cmp_map[cond];
+        if (cmp_map & MIPS_CMP_SWAP) {
+            TCGReg t = arg1;
+            arg1 = arg2;
+            arg2 = t;
+        }
+        tcg_out_opc_reg(s, s_opc, TCG_TMP0, arg1, arg2);
+        b_opc = (cmp_map & MIPS_CMP_INV ? OPC_BEQ : OPC_BNE);
+        arg1 = TCG_TMP0;
+        arg2 = TCG_REG_ZERO;
         break;
+
     default:
         tcg_abort();
         break;
     }
+
+    tcg_out_opc_br(s, b_opc, arg1, arg2);
+    l = &s->labels[label_index];
     if (l->has_value) {
         reloc_pc16(s->code_ptr - 1, l->u.value_ptr);
     } else {