From b4bbfe4bb91db310d903a149cfa5525295e4a70c Mon Sep 17 00:00:00 2001 From: nobu Date: Sat, 20 Oct 2018 02:49:18 +0000 Subject: [PATCH] complex.c: small optimization of Complex#** * complex.c (rb_complex_pow): calculate power of a Fixnum without allocating intermediate Complex objects, and avoid unexpected NaNs. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65190 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- complex.c | 95 ++++++++++++++++++++++----------------- internal.h | 3 ++ numeric.c | 16 +++++++ rational.c | 5 ++- test/ruby/test_complex.rb | 4 ++ 5 files changed, 79 insertions(+), 44 deletions(-) diff --git a/complex.c b/complex.c index ff6e3e038e..8a60a4fb4b 100644 --- a/complex.c +++ b/complex.c @@ -725,6 +725,19 @@ safe_mul(VALUE a, VALUE b, int az, int bz) return f_mul(a, b); } +static void +comp_mul(VALUE areal, VALUE aimag, VALUE breal, VALUE bimag, VALUE *real, VALUE *imag) +{ + int arzero = f_zero_p(areal); + int aizero = f_zero_p(aimag); + int brzero = f_zero_p(breal); + int bizero = f_zero_p(bimag); + *real = f_sub(safe_mul(areal, breal, arzero, brzero), + safe_mul(aimag, bimag, aizero, bizero)); + *imag = f_add(safe_mul(areal, bimag, arzero, bizero), + safe_mul(aimag, breal, aizero, brzero)); +} + /* * call-seq: * cmp * numeric -> complex @@ -742,19 +755,9 @@ rb_complex_mul(VALUE self, VALUE other) { if (RB_TYPE_P(other, T_COMPLEX)) { VALUE real, imag; - VALUE areal, aimag, breal, bimag; - int arzero, aizero, brzero, bizero; - get_dat2(self, other); - arzero = f_zero_p(areal = adat->real); - aizero = f_zero_p(aimag = adat->imag); - brzero = f_zero_p(breal = bdat->real); - bizero = f_zero_p(bimag = bdat->imag); - real = f_sub(safe_mul(areal, breal, arzero, brzero), - safe_mul(aimag, bimag, aizero, bizero)); - imag = f_add(safe_mul(areal, bimag, arzero, bizero), - safe_mul(aimag, breal, aizero, brzero)); + comp_mul(adat->real, adat->imag, bdat->real, bdat->imag, &real, &imag); return f_complex_new2(CLASS_OF(self), real, imag); } @@ -867,8 +870,8 @@ f_reciprocal(VALUE x) * Complex('i') ** 2 #=> (-1+0i) * Complex(-8) ** Rational(1, 3) #=> (1.0000000000000002+1.7320508075688772i) */ -static VALUE -nucomp_expt(VALUE self, VALUE other) +VALUE +rb_complex_pow(VALUE self, VALUE other) { if (k_numeric_p(other) && k_exact_zero_p(other)) return f_complex_new_bang1(CLASS_OF(self), ONE); @@ -898,38 +901,45 @@ nucomp_expt(VALUE self, VALUE other) return f_complex_polar(CLASS_OF(self), nr, ntheta); } if (FIXNUM_P(other)) { - if (f_gt_p(other, ZERO)) { - VALUE x, z; - long n; + long n = FIX2LONG(other); + if (n == 0) { + return nucomp_s_new_internal(CLASS_OF(self), ONE, ZERO); + } + if (n < 0) { + self = f_reciprocal(self); + other = rb_int_uminus(other); + n = -n; + } + { + get_dat1(self); + VALUE xr = dat->real, xi = dat->imag, zr = xr, zi = xi; - x = self; - z = x; - n = FIX2LONG(other) - 1; + if (f_zero_p(xi)) { + zr = rb_num_pow(zr, other); + } + else if (f_zero_p(xr)) { + zi = rb_num_pow(zi, other); + if (n & 2) zi = f_negate(zi); + if (!(n & 1)) { + VALUE tmp = zr; + zr = zi; + zi = tmp; + } + } + else { + while (--n) { + long q, r; - while (n) { - long q, r; - - while (1) { - get_dat1(x); - - q = n / 2; - r = n % 2; - - if (r) - break; - - x = nucomp_s_new_internal(CLASS_OF(self), - f_sub(f_mul(dat->real, dat->real), - f_mul(dat->imag, dat->imag)), - f_mul(f_mul(TWO, dat->real), dat->imag)); - n = q; - } - z = f_mul(z, x); - n--; - } - return z; + for (; q = n / 2, r = n % 2, r == 0; n = q) { + VALUE tmp = f_sub(f_mul(xr, xr), f_mul(xi, xi)); + xi = f_mul(f_mul(TWO, xr), xi); + xr = tmp; + } + comp_mul(zr, zi, xr, xi, &zr, &zi); + } + } + return nucomp_s_new_internal(CLASS_OF(self), zr, zi); } - return f_expt(f_reciprocal(self), rb_int_uminus(other)); } if (k_numeric_p(other) && f_real_p(other)) { VALUE r, theta; @@ -945,6 +955,7 @@ nucomp_expt(VALUE self, VALUE other) } return rb_num_coerce_bin(self, other, id_expt); } +#define nucomp_expt rb_complex_pow /* * call-seq: diff --git a/internal.h b/internal.h index b55121fbc7..f6fcd399b7 100644 --- a/internal.h +++ b/internal.h @@ -1174,6 +1174,7 @@ VALUE rb_complex_mul(VALUE, VALUE); VALUE rb_complex_abs(VALUE x); VALUE rb_complex_sqrt(VALUE x); VALUE rb_dbl_complex_polar(double abs, double ang); +VALUE rb_complex_pow(VALUE self, VALUE other); /* cont.c */ VALUE rb_obj_is_fiber(VALUE); @@ -1471,6 +1472,7 @@ VALUE rb_int_abs(VALUE num); VALUE rb_int_odd_p(VALUE num); int rb_int_positive_p(VALUE num); int rb_int_negative_p(VALUE num); +VALUE rb_num_pow(VALUE x, VALUE y); static inline VALUE rb_num_compare_with_zero(VALUE num, ID mid) @@ -1735,6 +1737,7 @@ VALUE rb_rational_reciprocal(VALUE x); VALUE rb_cstr_to_rat(const char *, int); VALUE rb_rational_abs(VALUE self); VALUE rb_rational_cmp(VALUE self, VALUE other); +VALUE rb_rational_pow(VALUE self, VALUE other); VALUE rb_numeric_quo(VALUE x, VALUE y); /* re.c */ diff --git a/numeric.c b/numeric.c index 292af0af27..d698fcedea 100644 --- a/numeric.c +++ b/numeric.c @@ -4077,6 +4077,22 @@ rb_int_pow(VALUE x, VALUE y) return Qnil; } +VALUE +rb_num_pow(VALUE x, VALUE y) +{ + VALUE z = rb_int_pow(x, y); + if (!NIL_P(z)) return z; + if (RB_FLOAT_TYPE_P(x)) return rb_float_pow(x, y); + if (SPECIAL_CONST_P(x)) return Qnil; + switch (BUILTIN_TYPE(x)) { + case T_COMPLEX: + return rb_complex_pow(x, y); + case T_RATIONAL: + return rb_rational_pow(x, y); + } + return Qnil; +} + /* * Document-method: Integer#== * Document-method: Integer#=== diff --git a/rational.c b/rational.c index d62a24ffbc..9712ce72bb 100644 --- a/rational.c +++ b/rational.c @@ -1001,8 +1001,8 @@ f_odd_p(VALUE integer) * Rational(1, 2) ** 0 #=> (1/1) * Rational(1, 2) ** 0.0 #=> 1.0 */ -static VALUE -nurat_expt(VALUE self, VALUE other) +VALUE +rb_rational_pow(VALUE self, VALUE other) { if (k_numeric_p(other) && k_exact_zero_p(other)) return f_rational_new_bang1(CLASS_OF(self), ONE); @@ -1077,6 +1077,7 @@ nurat_expt(VALUE self, VALUE other) return rb_num_coerce_bin(self, other, rb_intern("**")); } } +#define nurat_expt rb_rational_pow /* * call-seq: diff --git a/test/ruby/test_complex.rb b/test/ruby/test_complex.rb index 10289226fe..1180e9acb0 100644 --- a/test/ruby/test_complex.rb +++ b/test/ruby/test_complex.rb @@ -407,6 +407,10 @@ class Complex_Test < Test::Unit::TestCase r = c ** Rational(-2,3) assert_in_delta(0.432, r.real, 0.001) assert_in_delta(-0.393, r.imag, 0.001) + + c = Complex(0.0, -888888888888888.0)**8888 + assert_not_predicate(c.real, :nan?) + assert_not_predicate(c.imag, :nan?) end def test_cmp