Introduce a tier-1 JIT compiler based on x86-64 architecture

.github/workflows/main.yml

@@ -32,7 +32,9 @@ jobs:
     - name: gdbstub test
       run: |
             make distclean ENABLE_GDBSTUB=1 gdbstub-test
-
+    - name: JIT test
+      run: |
+            make ENABLE_JIT=1 clean check
   coding-style:
     runs-on: ubuntu-22.04
     steps:

.gitignore

@@ -21,3 +21,4 @@ build/path/
 tests/**/*.elf
 tests/arch-test-target/config.ini
 __pycache__/
+src/rv32_jit_template.c

Makefile

@@ -118,6 +118,21 @@ gdbstub-test: $(BIN)
 	$(Q).ci/gdbstub-test.sh && $(call notice, [OK])
 endif
 
+ENABLE_JIT ?= 0
+$(call set-feature, JIT)
+ifeq ($(call has, JIT), 1)
+OBJS_EXT += jit_x64.o 
+ifneq ($(processor), x86_64)
+$(error JIT mode only supports for x64 target currently.)
+endif
+
+src/rv32_jit_template.c:
+	$(Q)tools/gen-jit-template.py $(CFLAGS) > $@
+
+$(OUT)/jit_x64.o: src/jit_x64.c src/rv32_jit_template.c
+	$(VECHO) "  CC\t$@\n"
+	$(Q)$(CC) -o $@ $(CFLAGS) -c -MMD -MF [email protected] $<
+endif
 # For tail-call elimination, we need a specific set of build flags applied.
 # FIXME: On macOS + Apple Silicon, -fno-stack-protector might have a negative impact.
 $(OUT)/emulate.o: CFLAGS += -foptimize-sibling-calls -fomit-frame-pointer -fno-stack-check -fno-stack-protector
@@ -214,7 +229,7 @@ endif
 endif
 
 clean:
-	$(RM) $(BIN) $(OBJS) $(HIST_BIN) $(HIST_OBJS) $(deps) $(CACHE_OUT)
+	$(RM) $(BIN) $(OBJS) $(HIST_BIN) $(HIST_OBJS) $(deps) $(CACHE_OUT) src/rv32_jit_template.c
 distclean: clean
 	-$(RM) $(DOOM_DATA) $(QUAKE_DATA)
 	$(RM) -r $(OUT)/id1

mk/tools.mk

@@ -3,6 +3,7 @@ HIST_BIN := $(OUT)/rv_histogram
 # FIXME: riscv.o and map.o are dependencies of 'elf.o', not 'rv_histogram'.
 HIST_OBJS := \
 	riscv.o \
+	utils.o \
 	map.o \
 	elf.o \
 	decode.o \

src/cache.c

@@ -13,10 +13,13 @@
 #include "mpool.h"
 #include "utils.h"
 
-/* THRESHOLD is set to identify hot spots. Once the frequency of use for a block
- * exceeds the THRESHOLD, the JIT compiler flow is triggered.
+/* Currently, THRESHOLD is set to identify hot spots. Once the using frequency
+ * for a block exceeds the THRESHOLD, the tier-1 JIT compiler process is
+ * triggered.
+ * FIXME: Implement effective  profiler to detect hot spots, instead of simply
+ * relying on THRESHOLD.
  */
-#define THRESHOLD 1000
+#define THRESHOLD 4096
 
 static uint32_t cache_size, cache_size_bits;
 static struct mpool *cache_mp;
@@ -530,3 +533,62 @@ void cache_free(cache_t *cache)
     free(cache->map);
     free(cache);
 }
+
+#if !RV32_HAS(ARC)
+uint32_t cache_freq(struct cache *cache, uint32_t key)
+{
+    if (!cache->capacity ||
+        hlist_empty(&cache->map->ht_list_head[cache_hash(key)]))
+        return 0;
+    lfu_entry_t *entry = NULL;
+#ifdef __HAVE_TYPEOF
+    hlist_for_each_entry (entry, &cache->map->ht_list_head[cache_hash(key)],
+                          ht_list)
+#else
+    hlist_for_each_entry (entry, &cache->map->ht_list_head[cache_hash(key)],
+                          ht_list, lfu_entry_t)
+#endif
+    {
+        if (entry->key == key)
+            return entry->frequency;
+    }
+    return 0;
+}
+#endif
+
+#if RV32_HAS(JIT)
+bool cache_hot(struct cache *cache, uint32_t key)
+{
+    if (!cache->capacity ||
+        hlist_empty(&cache->map->ht_list_head[cache_hash(key)]))
+        return false;
+#if RV32_HAS(ARC)
+    arc_entry_t *entry = NULL;
+#ifdef __HAVE_TYPEOF
+    hlist_for_each_entry (entry, &cache->map->ht_list_head[cache_hash(key)],
+                          ht_list)
+#else
+    hlist_for_each_entry (entry, &cache->map->ht_list_head[cache_hash(key)],
+                          ht_list, arc_entry_t)
+#endif
+    {
+        if (entry->key == key && entry->frequency == THRESHOLD)
+            return true;
+    }
+#else
+    lfu_entry_t *entry = NULL;
+#ifdef __HAVE_TYPEOF
+    hlist_for_each_entry (entry, &cache->map->ht_list_head[cache_hash(key)],
+                          ht_list)
+#else
+    hlist_for_each_entry (entry, &cache->map->ht_list_head[cache_hash(key)],
+                          ht_list, lfu_entry_t)
+#endif
+    {
+        if (entry->key == key && entry->frequency == THRESHOLD)
+            return true;
+    }
+#endif
+    return false;
+}
+#endif

src/cache.h

@@ -5,6 +5,7 @@
 
 #pragma once
 
+#include <stdbool.h>
 #include <stdint.h>
 
 struct cache;
@@ -38,3 +39,17 @@ void *cache_put(struct cache *cache, uint32_t key, void *value);
  * @callback: a function for freeing cache entry completely
  */
 void cache_free(struct cache *cache);
+
+#if RV32_HAS(JIT)
+/**
+ * cache_hot - check whether the frequency of the cache entry exceeds the
+ * threshold or not
+ * @cache: a pointer points to target cache
+ * @key: the key of the specified entry
+ */
+bool cache_hot(struct cache *cache, uint32_t key);
+#endif
+
+#if !RV32_HAS(ARC)
+uint32_t cache_freq(struct cache *cache, uint32_t key);
+#endif