1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Linux/PA-RISC Project (http://www.parisc-linux.org/)
5  * Floating-point emulation code
6  *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
42     register unsigned int left, right, result, extent;  in sgl_fsub()  local
50     left = *leftptr;  in sgl_fsub()
55     Sgl_xortointp1(left,right,/*to*/save);  in sgl_fsub()
60     if ((result_exponent = Sgl_exponent(left)) == SGL_INFINITY_EXPONENT)  in sgl_fsub()
62 	if (Sgl_iszero_mantissa(left))   in sgl_fsub()
80 		*dstptr = left;  in sgl_fsub()
89             if (Sgl_isone_signaling(left))   in sgl_fsub()
95         	Sgl_set_quiet(left);  in sgl_fsub()
113  	    *dstptr = left;  in sgl_fsub()
116 	} /* End left NaN or Infinity processing */  in sgl_fsub()
150     Sgl_copytoint_exponentmantissa(left,signless_upper_left);  in sgl_fsub()
156 	/* Set the left operand to the larger one by XOR swap *  in sgl_fsub()
159 	Sgl_xorfromintp1(save,left,/*to*/left);  in sgl_fsub()
160 	result_exponent = Sgl_exponent(left);  in sgl_fsub()
161 	Sgl_invert_sign(left);  in sgl_fsub()
163     /* Invariant:  left is not smaller than right. */   in sgl_fsub()
171 	    if(Sgl_iszero_exponentmantissa(left))  in sgl_fsub()
177 		    Sgl_or_signs(left,/*with*/right);  in sgl_fsub()
181 		    Sgl_and_signs(left,/*with*/right);  in sgl_fsub()
186 		/* Left is not a zero and must be the result.  Trapped  in sgl_fsub()
187 		 * underflows are signaled if left is denormalized.  Result  in sgl_fsub()
192 	    	    sign_save = Sgl_signextendedsign(left);  in sgl_fsub()
193 		    Sgl_leftshiftby1(left);  in sgl_fsub()
194 		    Sgl_normalize(left,result_exponent);  in sgl_fsub()
195 		    Sgl_set_sign(left,/*using*/sign_save);  in sgl_fsub()
196                     Sgl_setwrapped_exponent(left,result_exponent,unfl);  in sgl_fsub()
197 		    *dstptr = left;  in sgl_fsub()
202 	    *dstptr = left;  in sgl_fsub()
215 		Sgl_subtract(left,/*minus*/right,/*into*/result);  in sgl_fsub()
232 		Sgl_addition(left,right,/*into*/result);  in sgl_fsub()
261     Sgl_clear_exponent_set_hidden(left);  in sgl_fsub()
262     diff_exponent = result_exponent - right_exponent;  in sgl_fsub()
276     Sgl_right_align(/*operand*/right,/*shifted by*/diff_exponent,  in sgl_fsub()
287 	Sgl_subtract_withextension(left,/*minus*/right,/*with*/extent,/*into*/result);  in sgl_fsub()
292 	     * and extension left until the hidden bit becomes one.  Not  in sgl_fsub()
308 		/* Must have been "x-x" or "x+(-x)". */  in sgl_fsub()
314 	    result_exponent--;  in sgl_fsub()
320 		    /* Denormalized, exponent should be zero.  Left operand *  in sgl_fsub()
333 	    /* Check for denormalized, exponent should be zero.  Left    *  in sgl_fsub()
343 	     * modified binary search.  We have already shifted the result  in sgl_fsub()
350 		if((result_exponent -= 8) <= 0  && !underflowtrap)  in sgl_fsub()
358 		if((result_exponent -= 4) <= 0 && !underflowtrap)  in sgl_fsub()
378 		    result_exponent -= 3;  in sgl_fsub()
385 		    result_exponent -= 2;  in sgl_fsub()
394 		    result_exponent -= 1;  in sgl_fsub()
418 	    Sgl_right_align(result,/*by*/(1-result_exponent),extent);  in sgl_fsub()
429 	Sgl_addition(left,right,/*to*/result);  in sgl_fsub()