diff options
| author | Marc Glisse <marc.glisse@inria.fr> | 2016-10-28 21:51:33 +0200 |
|---|---|---|
| committer | Marc Glisse <marc.glisse@inria.fr> | 2016-10-28 21:51:33 +0200 |
| commit | 4225225d5de516221eb771aacf5cc0615da96787 (patch) | |
| tree | 0675d96fd2620a29c76d0913286b2c2964079428 | |
| parent | ffb534049ff90767cd30e562930d67a6529d1908 (diff) | |
| download | gmp-4225225d5de516221eb771aacf5cc0615da96787.tar.gz | |
Optimize 1/q to call mpq_inv.
Also handle (-1)/q and 0/q. We could test for l == 1 at runtime and not just with __builtin_constant_p, it might be worth it, especially for non-gcc compilers.
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | gmpxx.h | 29 | ||||
| -rw-r--r-- | tests/cxx/t-ops.cc | 10 |
3 files changed, 42 insertions, 2 deletions
@@ -1,3 +1,8 @@ +2016-10-28 Marc Glisse <marc.glisse@inria.fr> + + * gmpxx.h (__gmp_binary_divides): Let 1/q call mpq_inv. + * tests/cxx/t-ops.cc (check_mpq): Test it. + 2016-08-29 Torbjörn Granlund <tg@gmplib.org> * All C files: Include just gmp-impl.h, make gmp-impl.h grab gmp.h. @@ -689,7 +689,17 @@ struct __gmp_binary_divides } } static void eval(mpq_ptr q, unsigned long int l, mpq_srcptr r) - { __GMPXX_TMPQ_UI; mpq_div (q, temp, r); } + { + if (__GMPXX_CONSTANT_TRUE(l == 0)) + mpq_set_ui(q, 0, 1); + else if (__GMPXX_CONSTANT_TRUE(l == 1)) + mpq_inv(q, r); + else + { + __GMPXX_TMPQ_UI; + mpq_div (q, temp, r); + } + } static void eval(mpq_ptr q, mpq_srcptr r, signed long int l) { if (__GMPXX_CONSTANT_TRUE(l >= 0)) @@ -706,7 +716,22 @@ struct __gmp_binary_divides } } static void eval(mpq_ptr q, signed long int l, mpq_srcptr r) - { __GMPXX_TMPQ_SI; mpq_div (q, temp, r); } + { + if (__GMPXX_CONSTANT_TRUE(l == 0)) + mpq_set_ui(q, 0, 1); + else if (__GMPXX_CONSTANT_TRUE(l == 1)) + mpq_inv(q, r); + else if (__GMPXX_CONSTANT_TRUE(l == -1)) + { + mpq_inv(q, r); + mpq_neg(q, q); + } + else + { + __GMPXX_TMPQ_SI; + mpq_div (q, temp, r); + } + } static void eval(mpq_ptr q, mpq_srcptr r, double d) { __GMPXX_TMPQ_D; mpq_div (q, r, temp); } static void eval(mpq_ptr q, double d, mpq_srcptr r) diff --git a/tests/cxx/t-ops.cc b/tests/cxx/t-ops.cc index a86da6036..ecc6bd07f 100644 --- a/tests/cxx/t-ops.cc +++ b/tests/cxx/t-ops.cc @@ -502,6 +502,16 @@ check_mpq (void) mpq_class c; c = a / b; ASSERT_ALWAYS(c == 0.75); } + { + mpq_class one = 1; + mpq_class x(2, 5); + ASSERT_ALWAYS(1 / x == one / x); + ASSERT_ALWAYS(1u / x == one / x); + x = (-1) / x; + ASSERT_ALWAYS(x == -2.5); + ASSERT_ALWAYS(0 / x == 0); + ASSERT_ALWAYS(0u / x == 0); + } // operator<< // operator>> |