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>
117 	} /* End left NaN or Infinity processing */  in dbl_fsub()
157 	/* Set the left operand to the larger one by XOR swap *  in dbl_fsub()
165     /* Invariant:  left is not smaller than right. */   in dbl_fsub()
188 		/* Left is not a zero and must be the result.  Trapped  in dbl_fsub()
189 		 * underflows are signaled if left is denormalized.  Result  in dbl_fsub()
266     diff_exponent = result_exponent - right_exponent;  in dbl_fsub()
296 	    /* A straight forward algorithm would now shift the result  in dbl_fsub()
297 	     * and extension left until the hidden bit becomes one.  Not  in dbl_fsub()
298 	     * all of the extension bits need participate in the shift.  in dbl_fsub()
300 	     * needed.  If only a single shift is needed then the guard  in dbl_fsub()
303 	     * shift is needed, then all bits to the right of the guard   in dbl_fsub()
313 		/* Must have been "x-x" or "x+(-x)". */  in dbl_fsub()
319 	    result_exponent--;  in dbl_fsub()
325 		    /* Denormalized, exponent should be zero.  Left operand *  in dbl_fsub()
338 	    /* Check for denormalized, exponent should be zero.  Left    *  in dbl_fsub()
343 	    /* Shift extension to complete one bit of normalization and  in dbl_fsub()
347 	    /* Discover first one bit to determine shift amount.  Use a  in dbl_fsub()
355 		if((result_exponent -= 8) <= 0  && !underflowtrap)  in dbl_fsub()
363 		if((result_exponent -= 4) <= 0 && !underflowtrap)  in dbl_fsub()
367 	     * otherwise select the proper shift. */  in dbl_fsub()
383 		    result_exponent -= 3;  in dbl_fsub()
390 		    result_exponent -= 2;  in dbl_fsub()
399 		    result_exponent -= 1;  in dbl_fsub()
423 	    Dbl_fix_overshift(resultp1,resultp2,(1-result_exponent),extent);  in dbl_fsub()
447      * all zeros so no shift is needed. */  in dbl_fsub()