77 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
			
		
		
	
	
			77 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
| #include <assert.h>
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| 
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| namespace factor
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| {
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| 
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| #define FRAME_RETURN_ADDRESS(frame,vm) *(void **)(vm->frame_successor(frame) + 1)
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| 
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| #define CALLSTACK_BOTTOM(ctx) (stack_frame *)(ctx->callstack_seg->end - sizeof(cell) * 5)
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| 
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| inline static void flush_icache(cell start, cell len) {}
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| 
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| /* In the instruction sequence:
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| 
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|    MOV EBX,...
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|    JMP blah
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| 
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|    the offset from the immediate operand to MOV to the instruction after
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|    the jump is a cell for the immediate operand, 4 bytes for the JMP
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|    destination, and one byte for the JMP opcode. */
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| static const fixnum xt_tail_pic_offset = 4 + 1;
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| 
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| static const unsigned char call_opcode = 0xe8;
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| static const unsigned char jmp_opcode = 0xe9;
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| 
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| inline static unsigned char call_site_opcode(cell return_address)
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| {
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| 	return *(unsigned char *)(return_address - 5);
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| }
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| 
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| inline static void check_call_site(cell return_address)
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| {
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| 	unsigned char opcode = call_site_opcode(return_address);
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| 	assert(opcode == call_opcode || opcode == jmp_opcode);
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| }
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| 
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| inline static void *get_call_target(cell return_address)
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| {
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| 	check_call_site(return_address);
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| 	return (void *)(*(int *)(return_address - 4) + return_address);
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| }
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| 
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| inline static void set_call_target(cell return_address, void *target)
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| {
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| 	check_call_site(return_address);
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| 	*(int *)(return_address - 4) = (u32)((cell)target - return_address);
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| }
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| 
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| inline static bool tail_call_site_p(cell return_address)
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| {
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| 	switch(call_site_opcode(return_address))
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| 	{
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| 	case jmp_opcode: return true;
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| 	case call_opcode: return false;
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| 	default: abort(); return false;
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| 	}
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| }
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| 
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| inline static unsigned int fpu_status(unsigned int status)
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| {
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| 	unsigned int r = 0;
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| 	
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| 	if (status & 0x01)
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| 		r |= FP_TRAP_INVALID_OPERATION;
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| 	if (status & 0x04)
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| 		r |= FP_TRAP_ZERO_DIVIDE;
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| 	if (status & 0x08)
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| 		r |= FP_TRAP_OVERFLOW;
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| 	if (status & 0x10)
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| 		r |= FP_TRAP_UNDERFLOW;
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| 	if (status & 0x20)
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| 		r |= FP_TRAP_INEXACT;
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| 
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| 	return r;
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| }
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| 
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| }
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