diff options
| author | Martin Liska <mliska@suse.cz> | 2016-12-02 09:36:01 +0100 |
|---|---|---|
| committer | Martin Liska <marxin@gcc.gnu.org> | 2016-12-02 08:36:01 +0000 |
| commit | a4f2895465da4c8856b119a5787b95db345567a9 (patch) | |
| tree | d78ade7d79b89f366b780063e24f411faa024243 /gcc/sreal.c | |
| parent | 32ff7e39c15206dada1406bdc06e18db9e02d248 (diff) | |
| download | gcc-a4f2895465da4c8856b119a5787b95db345567a9.zip gcc-a4f2895465da4c8856b119a5787b95db345567a9.tar.gz gcc-a4f2895465da4c8856b119a5787b95db345567a9.tar.bz2 | |
Fix runtime error: left shift of negative value (PR
PR ipa/78555
* sreal.c (sreal::to_int): Make absolute value before shifting.
(sreal::operator/): Likewise.
(sreal_verify_negative_division): New test.
(void sreal_c_tests): Call the new test.
* sreal.h (sreal::normalize_up): Use new SREAL_ABS and
SREAL_SIGN macros.
(sreal::normalize_down): Likewise.
From-SVN: r243163
Diffstat (limited to 'gcc/sreal.c')
| -rw-r--r-- | gcc/sreal.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/gcc/sreal.c b/gcc/sreal.c index 9c43b4e..52e530d 100644 --- a/gcc/sreal.c +++ b/gcc/sreal.c @@ -102,14 +102,14 @@ sreal::shift_right (int s) int64_t sreal::to_int () const { - int64_t sign = m_sig < 0 ? -1 : 1; + int64_t sign = SREAL_SIGN (m_sig); if (m_exp <= -SREAL_BITS) return 0; if (m_exp >= SREAL_PART_BITS) return sign * INTTYPE_MAXIMUM (int64_t); if (m_exp > 0) - return m_sig << m_exp; + return sign * (SREAL_ABS (m_sig) << m_exp); if (m_exp < 0) return m_sig >> -m_exp; return m_sig; @@ -229,7 +229,8 @@ sreal::operator/ (const sreal &other) const { gcc_checking_assert (other.m_sig != 0); sreal r; - r.m_sig = (m_sig << SREAL_PART_BITS) / other.m_sig; + r.m_sig + = SREAL_SIGN (m_sig) * (SREAL_ABS (m_sig) << SREAL_PART_BITS) / other.m_sig; r.m_exp = m_exp - other.m_exp - SREAL_PART_BITS; r.normalize (); return r; @@ -334,6 +335,18 @@ sreal_verify_shifting (void) verify_shifting (values[i]); } +/* Verify division by (of) a negative value. */ + +static void +sreal_verify_negative_division (void) +{ + ASSERT_EQ (sreal (1) / sreal (1), sreal (1)); + ASSERT_EQ (sreal (-1) / sreal (-1), sreal (1)); + ASSERT_EQ (sreal (-1234567) / sreal (-1234567), sreal (1)); + ASSERT_EQ (sreal (-1234567) / sreal (1234567), sreal (-1)); + ASSERT_EQ (sreal (1234567) / sreal (-1234567), sreal (-1)); +} + /* Run all of the selftests within this file. */ void sreal_c_tests () @@ -341,6 +354,7 @@ void sreal_c_tests () sreal_verify_basics (); sreal_verify_arithmetics (); sreal_verify_shifting (); + sreal_verify_negative_division (); } } // namespace selftest |