[Qemu-devel] [PATCH 3/7] tcg-i386: Implement movcond

[Richard Henderson <rth@twiddle.net>]

Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
---
 tcg/i386/tcg-target.c | 29 +++++++++++++++++++++++++++++
 tcg/i386/tcg-target.h |  7 ++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index 3017858..aa1fa9f 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -249,6 +249,7 @@ static inline int tcg_target_const_match(tcg_target_long val,
 #define OPC_ADD_GvEv	(OPC_ARITH_GvEv | (ARITH_ADD << 3))
 #define OPC_BSWAP	(0xc8 | P_EXT)
 #define OPC_CALL_Jz	(0xe8)
+#define OPC_CMOVCC      (0x40 | P_EXT)  /* ... plus condition code */
 #define OPC_CMP_GvEv	(OPC_ARITH_GvEv | (ARITH_CMP << 3))
 #define OPC_DEC_r32	(0x48)
 #define OPC_IMUL_GvEv	(0xaf | P_EXT)
@@ -936,6 +937,24 @@ static void tcg_out_setcond2(TCGContext *s, const TCGArg *args,
 }
 #endif
 
+static void tcg_out_movcond32(TCGContext *s, TCGCond cond, TCGArg dest,
+                              TCGArg c1, TCGArg c2, int const_c2,
+                              TCGArg v1)
+{
+    tcg_out_cmp(s, c1, c2, const_c2, 0);
+    tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond], dest, v1);
+}
+
+#if TCG_TARGET_REG_BITS == 64
+static void tcg_out_movcond64(TCGContext *s, TCGCond cond, TCGArg dest,
+                              TCGArg c1, TCGArg c2, int const_c2,
+                              TCGArg v1)
+{
+    tcg_out_cmp(s, c1, c2, const_c2, P_REXW);
+    tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond] | P_REXW, dest, v1);
+}
+#endif
+
 static void tcg_out_branch(TCGContext *s, int call, tcg_target_long dest)
 {
     tcg_target_long disp = dest - (tcg_target_long)s->code_ptr - 5;
@@ -1668,6 +1687,10 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_setcond32(s, args[3], args[0], args[1],
                           args[2], const_args[2]);
         break;
+    case INDEX_op_movcond_i32:
+        tcg_out_movcond32(s, args[5], args[0], args[1],
+                          args[2], const_args[2], args[3]);
+        break;
 
     OP_32_64(bswap16):
         tcg_out_rolw_8(s, args[0]);
@@ -1796,6 +1819,10 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_setcond64(s, args[3], args[0], args[1],
                           args[2], const_args[2]);
         break;
+    case INDEX_op_movcond_i64:
+        tcg_out_movcond64(s, args[5], args[0], args[1],
+                          args[2], const_args[2], args[3]);
+        break;
 
     case INDEX_op_bswap64_i64:
         tcg_out_bswap64(s, args[0]);
@@ -1880,6 +1907,7 @@ static const TCGTargetOpDef x86_op_defs[] = {
     { INDEX_op_setcond_i32, { "q", "r", "ri" } },
 
     { INDEX_op_deposit_i32, { "Q", "0", "Q" } },
+    { INDEX_op_movcond_i32, { "r", "r", "ri", "r", "0" } },
 
 #if TCG_TARGET_REG_BITS == 32
     { INDEX_op_mulu2_i32, { "a", "d", "a", "r" } },
@@ -1934,6 +1962,7 @@ static const TCGTargetOpDef x86_op_defs[] = {
     { INDEX_op_ext32u_i64, { "r", "r" } },
 
     { INDEX_op_deposit_i64, { "Q", "0", "Q" } },
+    { INDEX_op_movcond_i64, { "r", "r", "re", "r", "0" } },
 #endif
 
 #if TCG_TARGET_REG_BITS == 64
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 504f953..b356d76 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -86,7 +86,12 @@ typedef enum {
 #define TCG_TARGET_HAS_nand_i32         0
 #define TCG_TARGET_HAS_nor_i32          0
 #define TCG_TARGET_HAS_deposit_i32      1
+#if defined(__x86_64__) || defined(__i686__)
+/* Use cmov only if the compiler is already doing so.  */
+#define TCG_TARGET_HAS_movcond_i32      1
+#else
 #define TCG_TARGET_HAS_movcond_i32      0
+#endif
 
 #if TCG_TARGET_REG_BITS == 64
 #define TCG_TARGET_HAS_div2_i64         1
@@ -108,7 +113,7 @@ typedef enum {
 #define TCG_TARGET_HAS_nand_i64         0
 #define TCG_TARGET_HAS_nor_i64          0
 #define TCG_TARGET_HAS_deposit_i64      1
-#define TCG_TARGET_HAS_movcond_i64      0
+#define TCG_TARGET_HAS_movcond_i64      1
 #endif
 
 #define TCG_TARGET_deposit_i32_valid(ofs, len) \
-- 
1.7.11.4