[Qemu-devel] [PATCH 03/21] tcg-i386: Tidy ext8u and ext16u operations.

[Richard Henderson <rth@twiddle.net>]

Define OPC_MOVZBL and OPC_MOVZWL.  Factor opcode emission to
separate functions.  Don't restrict the input register to the
low 4 "q" registers; emit an AND instead if needed.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/i386/tcg-target.c |   68 ++++++++++++++++++++++++++++++------------------
 1 files changed, 42 insertions(+), 26 deletions(-)

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index 359f81b..2cc1191 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -161,6 +161,11 @@ static inline int tcg_target_const_match(tcg_target_long val,
         return 0;
 }
 
+#define P_EXT   0x100 /* 0x0f opcode prefix */
+
+#define OPC_MOVZBL	(0xb6 | P_EXT)
+#define OPC_MOVZWL	(0xb7 | P_EXT)
+
 #define ARITH_ADD 0
 #define ARITH_OR  1
 #define ARITH_ADC 2
@@ -194,8 +199,6 @@ static inline int tcg_target_const_match(tcg_target_long val,
 #define JCC_JLE 0xe
 #define JCC_JG  0xf
 
-#define P_EXT   0x100 /* 0x0f opcode prefix */
-
 static const uint8_t tcg_cond_to_jcc[10] = {
     [TCG_COND_EQ] = JCC_JE,
     [TCG_COND_NE] = JCC_JNE,
@@ -288,6 +291,27 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, int arg,
     tcg_out_modrm_offset(s, 0x89, arg, arg1, arg2);
 }
 
+static void tcg_out_ext8u(TCGContext *s, int dest, int src)
+{
+    if (src >= 4) {
+        tcg_out_mov(s, dest, src);
+        if (dest >= 4) {
+            tcg_out_modrm(s, 0x81, ARITH_AND, dest);
+            tcg_out32(s, 0xff);
+            return;
+        }
+        src = dest;
+    }
+    /* movzbl */
+    tcg_out_modrm(s, OPC_MOVZBL, dest, src);
+}
+
+static inline void tcg_out_ext16u(TCGContext *s, int dest, int src)
+{
+    /* movzwl */
+    tcg_out_modrm(s, OPC_MOVZWL, dest, src);
+}
+
 static inline void tgen_arithi(TCGContext *s, int c, int r0, int32_t val, int cf)
 {
     if (!cf && ((c == ARITH_ADD && val == 1) || (c == ARITH_SUB && val == -1))) {
@@ -300,11 +324,9 @@ static inline void tgen_arithi(TCGContext *s, int c, int r0, int32_t val, int cf
         tcg_out_modrm(s, 0x83, c, r0);
         tcg_out8(s, val);
     } else if (c == ARITH_AND && val == 0xffu && r0 < 4) {
-        /* movzbl */
-        tcg_out_modrm(s, 0xb6 | P_EXT, r0, r0);
+        tcg_out_ext8u(s, r0, r0);
     } else if (c == ARITH_AND && val == 0xffffu) {
-        /* movzwl */
-        tcg_out_modrm(s, 0xb7 | P_EXT, r0, r0);
+        tcg_out_ext16u(s, r0, r0);
     } else {
         tcg_out_modrm(s, 0x81, c, r0);
         tcg_out32(s, val);
@@ -645,12 +667,10 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
         tcg_out_modrm(s, 0xbf | P_EXT, data_reg, TCG_REG_EAX);
         break;
     case 0:
-        /* movzbl */
-        tcg_out_modrm(s, 0xb6 | P_EXT, data_reg, TCG_REG_EAX);
+        tcg_out_ext8u(s, data_reg, TCG_REG_EAX);
         break;
     case 1:
-        /* movzwl */
-        tcg_out_modrm(s, 0xb7 | P_EXT, data_reg, TCG_REG_EAX);
+        tcg_out_ext16u(s, data_reg, TCG_REG_EAX);
         break;
     case 2:
     default:
@@ -690,7 +710,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
     switch(opc) {
     case 0:
         /* movzbl */
-        tcg_out_modrm_offset(s, 0xb6 | P_EXT, data_reg, r0, GUEST_BASE);
+        tcg_out_modrm_offset(s, OPC_MOVZBL, data_reg, r0, GUEST_BASE);
         break;
     case 0 | 4:
         /* movsbl */
@@ -698,7 +718,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
         break;
     case 1:
         /* movzwl */
-        tcg_out_modrm_offset(s, 0xb7 | P_EXT, data_reg, r0, GUEST_BASE);
+        tcg_out_modrm_offset(s, OPC_MOVZWL, data_reg, r0, GUEST_BASE);
         if (bswap) {
             /* rolw $8, data_reg */
             tcg_out8(s, 0x66); 
@@ -850,12 +870,10 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
     } else {
         switch(opc) {
         case 0:
-            /* movzbl */
-            tcg_out_modrm(s, 0xb6 | P_EXT, TCG_REG_EDX, data_reg);
+            tcg_out_ext8u(s, TCG_REG_EDX, data_reg);
             break;
         case 1:
-            /* movzwl */
-            tcg_out_modrm(s, 0xb7 | P_EXT, TCG_REG_EDX, data_reg);
+            tcg_out_ext16u(s, TCG_REG_EDX, data_reg);
             break;
         case 2:
             tcg_out_mov(s, TCG_REG_EDX, data_reg);
@@ -881,12 +899,10 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
         tcg_out_mov(s, TCG_REG_EDX, addr_reg2);
         switch(opc) {
         case 0:
-            /* movzbl */
-            tcg_out_modrm(s, 0xb6 | P_EXT, TCG_REG_ECX, data_reg);
+            tcg_out_ext8u(s, TCG_REG_ECX, data_reg);
             break;
         case 1:
-            /* movzwl */
-            tcg_out_modrm(s, 0xb7 | P_EXT, TCG_REG_ECX, data_reg);
+            tcg_out_ext16u(s, TCG_REG_ECX, data_reg);
             break;
         case 2:
             tcg_out_mov(s, TCG_REG_ECX, data_reg);
@@ -1022,7 +1038,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         break;
     case INDEX_op_ld8u_i32:
         /* movzbl */
-        tcg_out_modrm_offset(s, 0xb6 | P_EXT, args[0], args[1], args[2]);
+        tcg_out_modrm_offset(s, OPC_MOVZBL, args[0], args[1], args[2]);
         break;
     case INDEX_op_ld8s_i32:
         /* movsbl */
@@ -1030,7 +1046,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         break;
     case INDEX_op_ld16u_i32:
         /* movzwl */
-        tcg_out_modrm_offset(s, 0xb7 | P_EXT, args[0], args[1], args[2]);
+        tcg_out_modrm_offset(s, OPC_MOVZWL, args[0], args[1], args[2]);
         break;
     case INDEX_op_ld16s_i32:
         /* movswl */
@@ -1177,10 +1193,10 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         tcg_out_modrm(s, 0xbf | P_EXT, args[0], args[1]);
         break;
     case INDEX_op_ext8u_i32:
-        tcg_out_modrm(s, 0xb6 | P_EXT, args[0], args[1]);
+        tcg_out_ext8u(s, args[0], args[1]);
         break;
     case INDEX_op_ext16u_i32:
-        tcg_out_modrm(s, 0xb7 | P_EXT, args[0], args[1]);
+        tcg_out_ext16u(s, args[0], args[1]);
         break;
 
     case INDEX_op_setcond_i32:
@@ -1275,8 +1291,8 @@ static const TCGTargetOpDef x86_op_defs[] = {
 
     { INDEX_op_ext8s_i32, { "r", "q" } },
     { INDEX_op_ext16s_i32, { "r", "r" } },
-    { INDEX_op_ext8u_i32, { "r", "q"} },
-    { INDEX_op_ext16u_i32, { "r", "r"} },
+    { INDEX_op_ext8u_i32, { "r", "r" } },
+    { INDEX_op_ext16u_i32, { "r", "r" } },
 
     { INDEX_op_setcond_i32, { "q", "r", "ri" } },
     { INDEX_op_setcond2_i32, { "r", "r", "r", "ri", "ri" } },
-- 
1.6.2.5