[Qemu-devel] [PATCH 10/10] tcg/mips: implement movcond op on MIPS32R2

[Aurelien Jarno <aurelien@aurel32.net>]

movcond operation can be implemented on MIPS32 Release 2 using the MOVN,
MOVZ, SLT and SLTU instructions.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 tcg/mips/tcg-target.c |   69 +++++++++++++++++++++++++++++++++++++++++++++++++
 tcg/mips/tcg-target.h |    8 ++++++
 2 files changed, 77 insertions(+)

diff --git a/tcg/mips/tcg-target.c b/tcg/mips/tcg-target.c
index b2e1056..44210e5 100644
--- a/tcg/mips/tcg-target.c
+++ b/tcg/mips/tcg-target.c
@@ -308,6 +308,8 @@ enum {
     OPC_SRAV     = OPC_SPECIAL | 0x07,
     OPC_JR       = OPC_SPECIAL | 0x08,
     OPC_JALR     = OPC_SPECIAL | 0x09,
+    OPC_MOVZ     = OPC_SPECIAL | 0x0A,
+    OPC_MOVN     = OPC_SPECIAL | 0x0B,
     OPC_MFHI     = OPC_SPECIAL | 0x10,
     OPC_MFLO     = OPC_SPECIAL | 0x12,
     OPC_MULT     = OPC_SPECIAL | 0x18,
@@ -735,6 +737,68 @@ static void tcg_out_brcond2(TCGContext *s, TCGCond cond, TCGArg arg1,
     reloc_pc16(label_ptr, (tcg_target_long) s->code_ptr);
 }
 
+static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
+                            TCGArg c1, TCGArg c2, TCGArg v)
+{
+    switch (cond) {
+    case TCG_COND_EQ:
+        if (c1 == 0) {
+            tcg_out_opc_reg(s, OPC_MOVZ, ret, v, c2);
+        } else if (c2 == 0) {
+            tcg_out_opc_reg(s, OPC_MOVZ, ret, v, c1);
+        } else {
+            tcg_out_opc_reg(s, OPC_XOR, TCG_REG_AT, c1, c2);
+            tcg_out_opc_reg(s, OPC_MOVZ, ret, v, TCG_REG_AT);
+        }
+        break;
+    case TCG_COND_NE:
+        if (c1 == 0) {
+            tcg_out_opc_reg(s, OPC_MOVN, ret, v, c2);
+        } else if (c2 == 0) {
+            tcg_out_opc_reg(s, OPC_MOVN, ret, v, c1);
+        } else {
+            tcg_out_opc_reg(s, OPC_XOR, TCG_REG_AT, c1, c2);
+            tcg_out_opc_reg(s, OPC_MOVN, ret, v, TCG_REG_AT);
+        }
+        break;
+    case TCG_COND_LT:
+        tcg_out_opc_reg(s, OPC_SLT, TCG_REG_AT, c1, c2);
+        tcg_out_opc_reg(s, OPC_MOVN, ret, v, TCG_REG_AT);
+        break;
+    case TCG_COND_LTU:
+        tcg_out_opc_reg(s, OPC_SLTU, TCG_REG_AT, c1, c2);
+        tcg_out_opc_reg(s, OPC_MOVN, ret, v, TCG_REG_AT);
+        break;
+    case TCG_COND_GE:
+        tcg_out_opc_reg(s, OPC_SLT, TCG_REG_AT, c1, c2);
+        tcg_out_opc_reg(s, OPC_MOVZ, ret, v, TCG_REG_AT);
+        break;
+    case TCG_COND_GEU:
+        tcg_out_opc_reg(s, OPC_SLTU, TCG_REG_AT, c1, c2);
+        tcg_out_opc_reg(s, OPC_MOVZ, ret, v, TCG_REG_AT);
+        break;
+    case TCG_COND_LE:
+        tcg_out_opc_reg(s, OPC_SLT, TCG_REG_AT, c2, c1);
+        tcg_out_opc_reg(s, OPC_MOVZ, ret, v, TCG_REG_AT);
+        break;
+    case TCG_COND_LEU:
+        tcg_out_opc_reg(s, OPC_SLTU, TCG_REG_AT, c2, c1);
+        tcg_out_opc_reg(s, OPC_MOVZ, ret, v, TCG_REG_AT);
+        break;
+    case TCG_COND_GT:
+        tcg_out_opc_reg(s, OPC_SLT, TCG_REG_AT, c2, c1);
+        tcg_out_opc_reg(s, OPC_MOVN, ret, v, TCG_REG_AT);
+        break;
+    case TCG_COND_GTU:
+        tcg_out_opc_reg(s, OPC_SLTU, TCG_REG_AT, c2, c1);
+        tcg_out_opc_reg(s, OPC_MOVN, ret, v, TCG_REG_AT);
+        break;
+    default:
+        tcg_abort();
+        break;
+    }
+}
+
 static void tcg_out_setcond(TCGContext *s, TCGCond cond, TCGReg ret,
                             TCGArg arg1, TCGArg arg2)
 {
@@ -1468,6 +1532,10 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_brcond2(s, args[4], args[0], args[1], args[2], args[3], args[5]);
         break;
 
+    case INDEX_op_movcond_i32:
+        tcg_out_movcond(s, args[5], args[0], args[1], args[2], args[3]);
+        break;
+
     case INDEX_op_setcond_i32:
         tcg_out_setcond(s, args[3], args[0], args[1], args[2]);
         break;
@@ -1559,6 +1627,7 @@ static const TCGTargetOpDef mips_op_defs[] = {
     { INDEX_op_deposit_i32, { "r", "0", "rZ" } },
 
     { INDEX_op_brcond_i32, { "rZ", "rZ" } },
+    { INDEX_op_movcond_i32, { "r", "r", "ri", "r", "0" } },
     { INDEX_op_setcond_i32, { "r", "rZ", "rZ" } },
     { INDEX_op_setcond2_i32, { "r", "rZ", "rZ", "rZ", "rZ" } },
 
diff --git a/tcg/mips/tcg-target.h b/tcg/mips/tcg-target.h
index 897a737..d147e70 100644
--- a/tcg/mips/tcg-target.h
+++ b/tcg/mips/tcg-target.h
@@ -86,7 +86,15 @@ typedef enum {
 #define TCG_TARGET_HAS_orc_i32          0
 #define TCG_TARGET_HAS_eqv_i32          0
 #define TCG_TARGET_HAS_nand_i32         0
+
+/* optional instructions only implemented on MIPS4, MIPS32 and Loongson 2 */
+#if defined(_MIPS_ARCH_MIPS4) || defined(_MIPS_ARCH_MIPS32) || \
+    defined(_MIPS_ARCH_MIPS32R2) || defined(_MIPS_ARCH_LOONGSON2E) || \
+    defined(_MIPS_ARCH_LOONGSON2F)
+#define TCG_TARGET_HAS_movcond_i32      1
+#else
 #define TCG_TARGET_HAS_movcond_i32      0
+#endif
 
 /* optional instructions only implemented on MIPS32R2 */
 #ifdef _MIPS_ARCH_MIPS32R2
-- 
1.7.10.4