[Qemu-devel] [PATCH 3/6] tcg-x86_64: Implement setcond and movcond.

[Richard Henderson]

Implement conditional moves in the x86_64 backend.

Signed-off-by: Richard Henderson <r...@twiddle.net>
---
 tcg/x86_64/tcg-target.c |   65 ++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/tcg/x86_64/tcg-target.c b/tcg/x86_64/tcg-target.c
index 2339091..e411755 100644
--- a/tcg/x86_64/tcg-target.c
+++ b/tcg/x86_64/tcg-target.c
@@ -491,9 +491,8 @@ static void tcg_out_jxx(TCGContext *s, int opc, int 
label_index)
     }
 }
 
-static void tcg_out_brcond(TCGContext *s, int cond, 
-                           TCGArg arg1, TCGArg arg2, int const_arg2,
-                           int label_index, int rexw)
+static void tcg_out_cond(TCGContext *s, int cond, TCGArg arg1,
+                         TCGArg arg2, int const_arg2, int rexw)
 {
     if (const_arg2) {
         if (arg2 == 0) {
@@ -508,9 +507,45 @@ static void tcg_out_brcond(TCGContext *s, int cond,
     } else {
         tcg_out_modrm(s, 0x01 | (ARITH_CMP << 3) | rexw, arg2, arg1);
     }
+}
+
+static void tcg_out_brcond(TCGContext *s, int cond,
+                           TCGArg arg1, TCGArg arg2, int const_arg2,
+                           int label_index, int rexw)
+{
+    tcg_out_cond(s, cond, arg1, arg2, const_arg2, rexw);
     tcg_out_jxx(s, tcg_cond_to_jcc[cond], label_index);
 }
 
+static void tcg_out_setcond(TCGContext *s, int cond, TCGArg arg0,
+                            TCGArg arg1, TCGArg arg2, int const_arg2, int rexw)
+{
+    int use_xor = (arg0 != arg1 && (const_arg2 || arg0 != arg2));
+
+    if (use_xor)
+        tcg_out_movi(s, TCG_TYPE_I32, arg0, 0);
+    tcg_out_cond(s, cond, arg1, arg2, const_arg2, rexw);
+    tcg_out_modrm(s, 0x90 | tcg_cond_to_jcc[cond] | P_EXT | P_REXB, 0, arg0);
+    if (!use_xor)
+        tgen_arithi32(s, ARITH_AND, arg0, 0xff);
+}
+
+static void tcg_out_movcond(TCGContext *s, int cond, TCGArg arg0,
+                            TCGArg arg1, TCGArg arg2, int const_arg2,
+                            TCGArg arg3, TCGArg arg4, int rexw)
+{
+    if (arg0 == arg3) {
+        cond = tcg_invert_cond(cond);
+        arg3 = arg4;
+        arg4 = arg0;
+    }
+
+    tcg_out_cond(s, cond, arg1, arg2, const_arg2, rexw);
+    if (arg0 != arg4)
+        tcg_out_mov(s, arg0, arg4);
+    tcg_out_modrm(s, 0x40 | tcg_cond_to_jcc[cond] | P_EXT | rexw, arg0, arg3);
+}
+
 #if defined(CONFIG_SOFTMMU)
 
 #include "../../softmmu_defs.h"
@@ -1197,6 +1232,24 @@ static inline void tcg_out_op(TCGContext *s, int opc, 
const TCGArg *args,
         tcg_out_modrm(s, 0x8b, args[0], args[1]);
         break;
 
+    case INDEX_op_setcond_i32:
+        tcg_out_setcond(s, args[3], args[0], args[1], args[2],
+                        const_args[2], 0);
+        break;
+    case INDEX_op_setcond_i64:
+        tcg_out_setcond(s, args[3], args[0], args[1], args[2],
+                        const_args[2], P_REXW);
+        break;
+
+    case INDEX_op_movcond_i32:
+        tcg_out_movcond(s, args[5], args[0], args[1], args[2],
+                        const_args[2], args[3], args[4], 0);
+        break;
+    case INDEX_op_movcond_i64:
+        tcg_out_movcond(s, args[5], args[0], args[1], args[2],
+                        const_args[2], args[3], args[4], P_REXW);
+        break;
+
     case INDEX_op_qemu_ld8u:
         tcg_out_qemu_ld(s, args, 0);
         break;
@@ -1376,6 +1429,12 @@ static const TCGTargetOpDef x86_64_op_defs[] = {
     { INDEX_op_ext16u_i64, { "r", "r"} },
     { INDEX_op_ext32u_i64, { "r", "r"} },
 
+    { INDEX_op_setcond_i32, { "r", "r", "re" } },
+    { INDEX_op_setcond_i64, { "r", "r", "re" } },
+
+    { INDEX_op_movcond_i32, { "r", "r", "re", "r", "r" } },
+    { INDEX_op_movcond_i64, { "r", "r", "re", "r", "r" } },
+
     { INDEX_op_qemu_ld8u, { "r", "L" } },
     { INDEX_op_qemu_ld8s, { "r", "L" } },
     { INDEX_op_qemu_ld16u, { "r", "L" } },
-- 
1.6.5.2