[newlib-cygwin] libm/math: Don't modify __ieee754_pow return values in pow

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=e108d04432bb0c0c223c447fcead5f7605342cba

commit e108d04432bb0c0c223c447fcead5f7605342cba
Author: Keith Packard via Newlib <newlib@sourceware.org>
Date:   Tue Aug 4 15:22:23 2020 -0700

    libm/math: Don't modify __ieee754_pow return values in pow
    
    The __ieee754 functions already return the right value in exception
    cases, so don't modify those. Setting the library to _POSIX_/_IEEE_
    mode now only affects whether errno is modified.
    
    Signed-off-by: Keith Packard <keithp@keithp.com>

Diff:
---
 newlib/libm/math/w_pow.c  | 14 +-------------
 newlib/libm/math/wf_pow.c | 14 +-------------
 2 files changed, 2 insertions(+), 26 deletions(-)

diff --git a/newlib/libm/math/w_pow.c b/newlib/libm/math/w_pow.c
index d8556a170..cf6099cf4 100644
--- a/newlib/libm/math/w_pow.c
+++ b/newlib/libm/math/w_pow.c
@@ -68,14 +68,6 @@ PORTABILITY
 	double z;
 	z=__ieee754_pow(x,y);
 	if(_LIB_VERSION == _IEEE_|| isnan(y)) return z;
-	if(isnan(x)) {
-	    if(y==0.0) { 
-		/* pow(NaN,0.0) */
-		/* Not an error.  */
-                return 1.0;
-	    } else 
-		return z;
-	}
 	if(x==0.0){ 
 	    if(y==0.0) {
 		/* pow(0.0,0.0) */
@@ -93,20 +85,16 @@ PORTABILITY
 	        if(isnan(z)) {
 		    /* neg**non-integral */
 		    errno = EDOM;
-		    return 0.0/0.0;
 	        } else {
 		    /* pow(x,y) overflow */
 		    errno = ERANGE;
-		    if(x<0.0&&rint(y)!=y)
-		      return -HUGE_VAL;
-		    return HUGE_VAL;
                 }
+		return z;
 	    }
 	} 
 	if(z==0.0&&finite(x)&&finite(y)) {
 	    /* pow(x,y) underflow */
 	    errno = ERANGE;
-	    return 0.0;
         } 
 	return z;
 #endif
diff --git a/newlib/libm/math/wf_pow.c b/newlib/libm/math/wf_pow.c
index e551e6b48..e9babf67c 100644
--- a/newlib/libm/math/wf_pow.c
+++ b/newlib/libm/math/wf_pow.c
@@ -34,14 +34,6 @@
 	float z;
 	z=__ieee754_powf(x,y);
 	if(_LIB_VERSION == _IEEE_|| isnan(y)) return z;
-	if(isnan(x)) {
-	    if(y==0.0f) {
-		/* powf(NaN,0.0) */
-		/* Not an error.  */
-		return 1.0f;
-	    } else 
-		return z;
-	}
 	if(x==0.0f){
 	    if(y==0.0f) {
 		/* powf(0.0,0.0) */
@@ -61,20 +53,16 @@
 		    errno = EDOM;
 		    /* Use a float divide, to avoid a soft-float double
 		       divide call on single-float only targets.  */
-		    return 0.0f/0.0f;
 		} else {
 		    /* powf(x,y) overflow */
 		    errno = ERANGE;
-		    if(x<0.0f&&rintf(y)!=y)
-		      return -HUGE_VALF;
-		    return HUGE_VALF;
 		}
+		return z;
 	    }
 	} 
 	if(z==0.0f&&finitef(x)&&finitef(y)) {
 	    /* powf(x,y) underflow */
 	    errno = ERANGE;
-	    return 0.0f;
         }
 	return z;
 #endif