sparc64/144900: commit references a PR

[dfilter service]

The following reply was made to PR sparc64/144900; it has been noted by GNATS.

From: dfilter at FreeBSD.ORG (dfilter service)
To: bug-followup at FreeBSD.org
Cc:  
Subject: Re: sparc64/144900: commit references a PR
Date: Sat, 20 Mar 2010 22:32:28 +0000 (UTC)

 Author: marius
 Date: Sat Mar 20 22:32:13 2010
 New Revision: 205397
 URL: http://svn.freebsd.org/changeset/base/205397
 
 Log:
   - While SPARC V9 allows tininess to be detected either before or after
     rounding (impl. dep. #55), the SPARC JPS1 responsible for SPARC64 and
     UltraSPARC processors defines that in all cases tinyness is detected
     before rounding, therefore rounding up to the smallest normalised
     number should set the underflow flag.
   - If an infinite result is rounded down, the result should have an
     exponent 1 less than the value for infinity.
   
   PR:		144900
   Submitted by:	Peter Jeremy
   MFC after:	3 days
 
 Modified:
   head/lib/libc/sparc64/fpu/fpu_implode.c
 
 Modified: head/lib/libc/sparc64/fpu/fpu_implode.c
 ==============================================================================
 --- head/lib/libc/sparc64/fpu/fpu_implode.c	Sat Mar 20 22:12:15 2010	(r205396)
 +++ head/lib/libc/sparc64/fpu/fpu_implode.c	Sat Mar 20 22:32:13 2010	(r205397)
 @@ -329,8 +329,9 @@ __fpu_ftos(fe, fp)
  	 * right to introduce leading zeroes.  Rounding then acts
  	 * differently for normals and subnormals: the largest subnormal
  	 * may round to the smallest normal (1.0 x 2^minexp), or may
 -	 * remain subnormal.  In the latter case, signal an underflow
 -	 * if the result was inexact or if underflow traps are enabled.
 +	 * remain subnormal.  A number that is subnormal before rounding
 +	 * will signal an underflow if the result is inexact or if underflow
 +	 * traps are enabled.
  	 *
  	 * Rounding a normal, on the other hand, always produces another
  	 * normal (although either way the result might be too big for
 @@ -345,8 +346,10 @@ __fpu_ftos(fe, fp)
  	if ((exp = fp->fp_exp + SNG_EXP_BIAS) <= 0) {	/* subnormal */
  		/* -NG for g,r; -SNG_FRACBITS-exp for fraction */
  		(void) __fpu_shr(fp, FP_NMANT - FP_NG - SNG_FRACBITS - exp);
 -		if (fpround(fe, fp) && fp->fp_mant[3] == SNG_EXP(1))
 +		if (fpround(fe, fp) && fp->fp_mant[3] == SNG_EXP(1)) {
 +			fe->fe_cx |= FSR_UF;
  			return (sign | SNG_EXP(1) | 0);
 +		}
  		if ((fe->fe_cx & FSR_NX) ||
  		    (fe->fe_fsr & (FSR_UF << FSR_TEM_SHIFT)))
  			fe->fe_cx |= FSR_UF;
 @@ -407,6 +410,7 @@ zero:		res[1] = 0;
  	if ((exp = fp->fp_exp + DBL_EXP_BIAS) <= 0) {
  		(void) __fpu_shr(fp, FP_NMANT - FP_NG - DBL_FRACBITS - exp);
  		if (fpround(fe, fp) && fp->fp_mant[2] == DBL_EXP(1)) {
 +			fe->fe_cx |= FSR_UF;
  			res[1] = 0;
  			return (sign | DBL_EXP(1) | 0);
  		}
 @@ -426,7 +430,7 @@ zero:		res[1] = 0;
  			return (sign | DBL_EXP(DBL_EXP_INFNAN) | 0);
  		}
  		res[1] = ~0;
 -		return (sign | DBL_EXP(DBL_EXP_INFNAN) | DBL_MASK);
 +		return (sign | DBL_EXP(DBL_EXP_INFNAN - 1) | DBL_MASK);
  	}
  done:
  	res[1] = fp->fp_mant[3];
 @@ -468,6 +472,7 @@ zero:		res[1] = res[2] = res[3] = 0;
  	if ((exp = fp->fp_exp + EXT_EXP_BIAS) <= 0) {
  		(void) __fpu_shr(fp, FP_NMANT - FP_NG - EXT_FRACBITS - exp);
  		if (fpround(fe, fp) && fp->fp_mant[0] == EXT_EXP(1)) {
 +			fe->fe_cx |= FSR_UF;
  			res[1] = res[2] = res[3] = 0;
  			return (sign | EXT_EXP(1) | 0);
  		}
 @@ -487,7 +492,7 @@ zero:		res[1] = res[2] = res[3] = 0;
  			return (sign | EXT_EXP(EXT_EXP_INFNAN) | 0);
  		}
  		res[1] = res[2] = res[3] = ~0;
 -		return (sign | EXT_EXP(EXT_EXP_INFNAN) | EXT_MASK);
 +		return (sign | EXT_EXP(EXT_EXP_INFNAN - 1) | EXT_MASK);
  	}
  done:
  	res[1] = fp->fp_mant[1];
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