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/flt-32/s_scalblnf.c | 8 +++++--- sysdeps/ieee754/flt-32/s_scalbnf.c | 8 +++++--- 2 files changed, 10 insertions(+), 6 deletions(-) (limited to 'sysdeps/ieee754/flt-32') diff --git a/sysdeps/ieee754/flt-32/s_scalblnf.c b/sysdeps/ieee754/flt-32/s_scalblnf.c index 5256c32592..2a2d7ab651 100644 --- a/sysdeps/ieee754/flt-32/s_scalblnf.c +++ b/sysdeps/ieee754/flt-32/s_scalblnf.c @@ -35,11 +35,13 @@ __scalblnf (float x, long int n) k = ((ix&0x7f800000)>>23) - 25; } if (__builtin_expect(k==0xff, 0)) return x+x; /* NaN or Inf */ - k = k+n; - if (__builtin_expect(n> 50000 || k > 0xfe, 0)) - return huge*copysignf(huge,x); /* overflow */ if (__builtin_expect(n< -50000, 0)) return tiny*copysignf(tiny,x); /*underflow*/ + if (__builtin_expect(n> 50000 || k+n > 0xfe, 0)) + return huge*copysignf(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_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;} if (k <= -25) diff --git a/sysdeps/ieee754/flt-32/s_scalbnf.c b/sysdeps/ieee754/flt-32/s_scalbnf.c index 3be2925a03..a7cb1a1a49 100644 --- a/sysdeps/ieee754/flt-32/s_scalbnf.c +++ b/sysdeps/ieee754/flt-32/s_scalbnf.c @@ -35,11 +35,13 @@ __scalbnf (float x, int n) k = ((ix&0x7f800000)>>23) - 25; } if (__builtin_expect(k==0xff, 0)) return x+x; /* NaN or Inf */ - k = k+n; - if (__builtin_expect(n> 50000 || k > 0xfe, 0)) - return huge*__copysignf(huge,x); /* overflow */ if (__builtin_expect(n< -50000, 0)) return tiny*__copysignf(tiny,x); /*underflow*/ + if (__builtin_expect(n> 50000 || k+n > 0xfe, 0)) + return huge*__copysignf(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_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;} if (k <= -25) -- cgit v1.2.3-70-g09d2