nelhage / bemu

A just-in-time compiler for MIT 6.004's "Beta" processor.

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bemu / bt.h
100644 34 lines (27 sloc) 0.962 kb
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#ifndef __BT_H__
#define __BT_H__
 
#define MAX_BYTES_PER_INSTRUCTION       24
#define MAX_FRAG_SIZE                   10
#define PC_CHECK_SIZE                   12
#define CCBUFF_PROLOGUE_SIZE            26
#define CCBUFF_EPILOGUE_SIZE            11
#define CCBUFF_MAX_SIZE                 (MAX_BYTES_PER_INSTRUCTION * \
                                         MAX_FRAG_SIZE               \
                                         + CCBUFF_EPILOGUE_SIZE      \
                                         + CCBUFF_PROLOGUE_SIZE      \
                                         + PC_CHECK_SIZE)
#define PGSIZE                          0x1000
 
typedef struct {
    byteptr start_pc;
    bdecode  insts[MAX_FRAG_SIZE];
    bool     tail;
    uint8_t  ninsts;
} decode_frag;
 
typedef struct compiled_frag {
    byteptr start_pc;
    struct compiled_frag *hash_next;
    uint8_t *code;
} compiled_frag;
 
#define HASH_PC(pc) (((pc) >> 2) & 0xFF)
 
void bt_run();
 
#endif