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-96/s_scalblnl.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'sysdeps/ieee754/ldbl-96/s_scalblnl.c') diff --git a/sysdeps/ieee754/ldbl-96/s_scalblnl.c b/sysdeps/ieee754/ldbl-96/s_scalblnl.c index ada587b9d5..755a212555 100644 --- a/sysdeps/ieee754/ldbl-96/s_scalblnl.c +++ b/sysdeps/ieee754/ldbl-96/s_scalblnl.c @@ -43,11 +43,13 @@ __scalblnl (long double x, long int n) k = (hx&0x7fff) - 63; } if (__builtin_expect(k==0x7fff, 0)) return x+x; /* NaN or Inf */ - k = k+n; - if (__builtin_expect(n> 50000 || k > 0x7ffe, 0)) - return huge*__copysignl(huge,x); /* overflow */ if (__builtin_expect(n< -50000, 0)) return tiny*__copysignl(tiny,x); + if (__builtin_expect(n> 50000 || k+n > 0x7ffe, 0)) + 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 (__builtin_expect(k > 0, 1)) /* normal result */ {SET_LDOUBLE_EXP(x,(es&0x8000)|k); return x;} if (k <= -63) -- cgit 1.4.1