Refine "N_JIT_CACHE_ENTRIES"

Author: vacantron

src/jit.h

@@ -59,7 +59,11 @@ typedef void (*exec_t2c_func_t)(riscv_t *);
  * instructions generated by T2C. Like hardware cache, the old jit-cache will be
  * replaced by the new one which uses the same slot.
  */
-#define MAX_JIT_CACHE_TABLE_ENTRIES (1 << 12)
+
+/* The size of jit-cache table should be the power of 2, thus, we can easily
+ * access the element by masking the program counter.
+ */
+#define N_JIT_CACHE_ENTRIES (1 << 12)
 
 struct jit_cache {
     uint64_t pc; /* program counter, easy to build LLVM IR with 64-bit width */

src/t2c.c

@@ -318,7 +318,7 @@ void t2c_compile(riscv_t *rv, block_t *block)
 #if RV32_HAS(JIT_CACHE)
 struct jit_cache *jit_cache_init()
 {
-    return calloc(MAX_JIT_CACHE_TABLE_ENTRIES, sizeof(struct jit_cache));
+    return calloc(N_JIT_CACHE_ENTRIES, sizeof(struct jit_cache));
 }
 
 void jit_cache_exit(struct jit_cache *cache)
@@ -328,14 +328,14 @@ void jit_cache_exit(struct jit_cache *cache)
 
 void jit_cache_update(struct jit_cache *cache, uint32_t pc, void *entry)
 {
-    uint32_t pos = pc & (MAX_JIT_CACHE_TABLE_ENTRIES - 1);
+    uint32_t pos = pc & (N_JIT_CACHE_ENTRIES - 1);
 
     cache[pos].pc = pc;
     cache[pos].entry = entry;
 }
 
 void jit_cache_clear(struct jit_cache *cache)
 {
-    memset(cache, 0, MAX_JIT_CACHE_TABLE_ENTRIES * sizeof(struct jit_cache));
+    memset(cache, 0, N_JIT_CACHE_ENTRIES * sizeof(struct jit_cache));
 }
 #endif

src/t2c_template.c

@@ -54,8 +54,7 @@ FORCE_INLINE void t2c_jit_cache_helper(LLVMBuilderRef *builder,
     /* get index */
     LLVMValueRef hash = LLVMBuildAnd(
         *builder, addr,
-        LLVMConstInt(LLVMInt32Type(), MAX_JIT_CACHE_TABLE_ENTRIES - 1, false),
-        "");
+        LLVMConstInt(LLVMInt32Type(), N_JIT_CACHE_ENTRIES - 1, false), "");
 
     /* get jit_cache_t::pc */
     LLVMValueRef cast =