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31 lines
648 B
31 lines
648 B
7 years ago
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/* from http://blog.llvm.org/2010/01/address-of-label-and-indirect-branches.html
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*/
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static int fn(const char* opcodes) {
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static const void* codetable[] = {&&RETURN, &&INCREMENT, &&DECREMENT,
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&&DOUBLE, &&SWAPWORD};
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int result = 0;
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goto* codetable[*(opcodes++)];
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RETURN:
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return result;
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INCREMENT:
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result++;
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goto* codetable[*(opcodes++)];
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DECREMENT:
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result--;
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goto* codetable[*(opcodes++)];
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DOUBLE:
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result <<= 1;
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goto* codetable[*(opcodes++)];
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SWAPWORD:
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result = (result << 16) | (result >> 16);
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goto* codetable[*(opcodes++)];
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}
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5 years ago
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int main() {
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char opcodes[10];
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return fn(opcodes);
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}
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