fpubext.c

来自「这是一个潜入式开发的c语言代码」· C语言 代码 · 共 45 行

#include "fpubext.h"

VOID SetMode(BYTE* from, REGINT sourcemode, BYTE* to, REGINT targetmode)
{
	if(sourcemode == targetmode)
	{
		memcpy(to, from, 8);
	}
	else // only think about HL,LH IEEE DOUBLE
	{
		BYTE b[8];
		memcpy((BYTE*)&b, from, 8);
		memcpy(to, (BYTE*)(&b)+4, 4);
		memcpy(to+4, (BYTE*)&b, 4);
	}
}

/* parase double value in system matched format */
DOUBLE ext_ParaseDouble(BYTE* buffer, REGINT mode)
{
	DOUBLE result = 0;
	if(mode == __SYS_DOUBLE_MODE__)
	{
		memcpy(&result, buffer, 8);
	}
	else
	{
		SetMode(buffer, mode, &result, __SYS_DOUBLE_MODE__);
	}
	return result;
}

/* parase system double into target mode bytes */
VOID ext_ToBuffer(DOUBLE value, REGINT targetMode, BYTE* buffer)
{
	if(targetMode == __SYS_DOUBLE_MODE__)
	{
		memcpy(buffer, &value, 8);
	}
	else
	{
		SetMode(&value, __SYS_DOUBLE_MODE__, buffer, targetMode);
	}
}