Add TCG optimizations stub

Added file tcg/optimize.c to hold TCG optimizations. Function tcg_optimize
is called from tcg_gen_code_common. It calls other functions performing
specific optimizations. Stub for constant folding was added.

Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

Makefile.target

@@ -72,7 +72,7 @@ all: $(PROGS) stap
 #########################################################
 # cpu emulator library
 libobj-y = exec.o translate-all.o cpu-exec.o translate.o
-libobj-y += tcg/tcg.o
+libobj-y += tcg/tcg.o tcg/optimize.o
 libobj-y += fpu/softfloat.o
 libobj-y += op_helper.o helper.o
 ifeq ($(TARGET_BASE_ARCH), i386)

tcg/optimize.c

@@ -0,0 +1,97 @@
+/*
+ * Optimizations for Tiny Code Generator for QEMU
+ *
+ * Copyright (c) 2010 Samsung Electronics.
+ * Contributed by Kirill Batuzov <batuzovk@ispras.ru>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "qemu-common.h"
+#include "tcg-op.h"
+
+#if TCG_TARGET_REG_BITS == 64
+#define CASE_OP_32_64(x)                        \
+        glue(glue(case INDEX_op_, x), _i32):    \
+        glue(glue(case INDEX_op_, x), _i64)
+#else
+#define CASE_OP_32_64(x)                        \
+        glue(glue(case INDEX_op_, x), _i32)
+#endif
+
+static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
+                                    TCGArg *args, TCGOpDef *tcg_op_defs)
+{
+    int i, nb_ops, op_index, op, nb_temps, nb_globals;
+    const TCGOpDef *def;
+    TCGArg *gen_args;
+
+    nb_temps = s->nb_temps;
+    nb_globals = s->nb_globals;
+
+    nb_ops = tcg_opc_ptr - gen_opc_buf;
+    gen_args = args;
+    for (op_index = 0; op_index < nb_ops; op_index++) {
+        op = gen_opc_buf[op_index];
+        def = &tcg_op_defs[op];
+        switch (op) {
+        case INDEX_op_call:
+            i = (args[0] >> 16) + (args[0] & 0xffff) + 3;
+            while (i) {
+                *gen_args = *args;
+                args++;
+                gen_args++;
+                i--;
+            }
+            break;
+        case INDEX_op_set_label:
+        case INDEX_op_jmp:
+        case INDEX_op_br:
+        CASE_OP_32_64(brcond):
+            for (i = 0; i < def->nb_args; i++) {
+                *gen_args = *args;
+                args++;
+                gen_args++;
+            }
+            break;
+        default:
+            for (i = 0; i < def->nb_args; i++) {
+                gen_args[i] = args[i];
+            }
+            args += def->nb_args;
+            gen_args += def->nb_args;
+            break;
+        }
+    }
+
+    return gen_args;
+}
+
+TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr,
+        TCGArg *args, TCGOpDef *tcg_op_defs)
+{
+    TCGArg *res;
+    res = tcg_constant_folding(s, tcg_opc_ptr, args, tcg_op_defs);
+    return res;
+}

tcg/tcg.c

@@ -24,6 +24,7 @@
 
 /* define it to use liveness analysis (better code) */
 #define USE_LIVENESS_ANALYSIS
+#define USE_TCG_OPTIMIZATIONS
 
 #include "config.h"
 
@@ -2035,6 +2036,11 @@ static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
     }
 #endif
 
+#ifdef USE_TCG_OPTIMIZATIONS
+    gen_opparam_ptr =
+        tcg_optimize(s, gen_opc_ptr, gen_opparam_buf, tcg_op_defs);
+#endif
+
 #ifdef CONFIG_PROFILER
     s->la_time -= profile_getclock();
 #endif

tcg/tcg.h

@@ -502,6 +502,9 @@ void tcg_gen_callN(TCGContext *s, TCGv_ptr func, unsigned int flags,
 void tcg_gen_shifti_i64(TCGv_i64 ret, TCGv_i64 arg1,
                         int c, int right, int arith);
 
+TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr, TCGArg *args,
+                     TCGOpDef *tcg_op_def);
+
 /* only used for debugging purposes */
 void tcg_register_helper(void *func, const char *name);
 const char *tcg_helper_get_name(TCGContext *s, void *func);