From a6d06d7b86f724046b462115556d0df682f9f703 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Fri, 2 Mar 2012 15:32:56 +0000 Subject: Fix scalbn, scalbln integer overflow. --- sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c') diff --git a/sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c b/sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c index a52cd42..48102ef 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c @@ -52,10 +52,12 @@ long double __scalbnl (long double x, int n) k = ((hx>>52)&0x7ff) - 54; } else if (k==0x7ff) return x+x; /* NaN or Inf */ - k = k+n; - if (n> 50000 || k > 0x7fe) - return huge*__copysignl(huge,x); /* overflow */ if (n< -50000) return tiny*__copysignl(tiny,x); /*underflow */ + if (n> 50000 || k+n > 0x7fe) + return huge*__copysignl(huge,x); /* overflow */ + /* Now k and n are bounded we know that k = k+n does not + overflow. */ + k = k+n; if (k > 0) { /* normal result */ hx = (hx&0x800fffffffffffffULL)|(k<<52); if ((lx & 0x7fffffffffffffffULL) == 0) { /* low part +-0 */ -- cgit v1.1