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| author | Joseph Myers <joseph@codesourcery.com> | 2012-03-02 15:32:56 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2012-03-02 15:32:56 +0000 |
| commit | a6d06d7b86f724046b462115556d0df682f9f703 (patch) | |
| tree | 640870a7d978c8a224fe317e862b65fddba6f40e /sysdeps/ieee754/dbl-64/s_scalbln.c | |
| parent | 07e12bb391ae84eb74817d42feda42cff7f687e5 (diff) | |
| download | glibc-a6d06d7b86f724046b462115556d0df682f9f703.tar.gz glibc-a6d06d7b86f724046b462115556d0df682f9f703.tar.xz glibc-a6d06d7b86f724046b462115556d0df682f9f703.zip | |
Fix scalbn, scalbln integer overflow.
Diffstat (limited to 'sysdeps/ieee754/dbl-64/s_scalbln.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/s_scalbln.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_scalbln.c b/sysdeps/ieee754/dbl-64/s_scalbln.c index 89174b47fb..b5903c97d0 100644 --- a/sysdeps/ieee754/dbl-64/s_scalbln.c +++ b/sysdeps/ieee754/dbl-64/s_scalbln.c @@ -38,11 +38,13 @@ __scalbln (double x, long int n) k = ((hx&0x7ff00000)>>20) - 54; } if (__builtin_expect(k==0x7ff, 0)) return x+x; /* NaN or Inf */ - k = k+n; - if (__builtin_expect(n> 50000 || k > 0x7fe, 0)) - return huge*__copysign(huge,x); /* overflow */ if (__builtin_expect(n< -50000, 0)) return tiny*__copysign(tiny,x); /*underflow*/ + if (__builtin_expect(n> 50000 || k+n > 0x7fe, 0)) + return huge*__copysign(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_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); return x;} if (k <= -54) |