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| author | Joseph Myers <joseph@codesourcery.com> | 2015-05-21 23:05:45 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-05-21 23:05:45 +0000 |
| commit | 89f3b6e18c6e7833438789746fcfc2e7189f7cac (patch) | |
| tree | 285370ecb7b84c7ad70b289779c1dd141e549a8d /sysdeps/ieee754 | |
| parent | 9d12d7652b830635528639ece2206ecf5bb9ffbf (diff) | |
| download | glibc-89f3b6e18c6e7833438789746fcfc2e7189f7cac.zip glibc-89f3b6e18c6e7833438789746fcfc2e7189f7cac.tar.gz glibc-89f3b6e18c6e7833438789746fcfc2e7189f7cac.tar.bz2 | |
Fix sysdeps/ieee754/dbl-64/mpa.c for -Wuninitialized.
If you remove the "override CFLAGS += -Wno-uninitialized" in
math/Makefile, one of the errors you get is:
../sysdeps/ieee754/dbl-64/mpa.c: In function '__mp_dbl.part.0':
../sysdeps/ieee754/dbl-64/mpa.c:183:5: error: 'c' may be used uninitialized in this function [-Werror=maybe-uninitialized]
c *= X[0];
The problem is that the p < 5 case initializes c if p is 1, 2, 3 or 4
but not otherwise, and in fact p is positive for all calls to this
function so the uninitialized case can't actually occur. This patch
replaces the "if (p == 4)" last case with a comment so the compiler
can see that all paths do initialize c.
Tested for x86_64.
* sysdeps/ieee754/dbl-64/mpa.c (norm): Remove if condition on
(p == 4) case.
Diffstat (limited to 'sysdeps/ieee754')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/mpa.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sysdeps/ieee754/dbl-64/mpa.c b/sysdeps/ieee754/dbl-64/mpa.c index 7d6b0c5..7b52da9 100644 --- a/sysdeps/ieee754/dbl-64/mpa.c +++ b/sysdeps/ieee754/dbl-64/mpa.c @@ -119,7 +119,8 @@ __cpy (const mp_no *x, mp_no *y, int p) #ifndef NO___MP_DBL /* Convert a multiple precision number *X into a double precision - number *Y, normalized case (|x| >= 2**(-1022))). */ + number *Y, normalized case (|x| >= 2**(-1022))). X has precision + P, which is positive. */ static void norm (const mp_no *x, double *y, int p) { @@ -135,7 +136,7 @@ norm (const mp_no *x, double *y, int p) c = X[1] + R * X[2]; else if (p == 3) c = X[1] + R * (X[2] + R * X[3]); - else if (p == 4) + else /* p == 4. */ c = (X[1] + R * X[2]) + R * R * (X[3] + R * X[4]); } else |