From 7048fbdf59509e4f52eff56d7c044ed28eb67727 Mon Sep 17 00:00:00 2001 From: Peter Zhu Date: Fri, 26 Jul 2024 11:10:39 -0400 Subject: Fix floor when ndigits is large [Bug #20654] This commit fixes Integer#floor and Float#floor when the number is negative and ndigits is large such that 10**ndigits is a bignum. Previously, it would return 0 in such cases. However, this would cause unexpected behaviour such as: puts -1.floor(-5) # => -100000 puts -1.floor(-10) # => -10000000000 puts -1.floor(-20) # => 0 This commit changes the last result so that it will return -100000000000000000000. --- numeric.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'numeric.c') diff --git a/numeric.c b/numeric.c index 7489d96dd2..41e1e18d50 100644 --- a/numeric.c +++ b/numeric.c @@ -2372,11 +2372,7 @@ rb_int_round(VALUE num, int ndigits, enum ruby_num_rounding_mode mode) static VALUE rb_int_floor(VALUE num, int ndigits) { - VALUE f; - - if (int_round_zero_p(num, ndigits)) - return INT2FIX(0); - f = int_pow(10, -ndigits); + VALUE f = int_pow(10, -ndigits); if (FIXNUM_P(num) && FIXNUM_P(f)) { SIGNED_VALUE x = FIX2LONG(num), y = FIX2LONG(f); int neg = x < 0; @@ -2385,11 +2381,13 @@ rb_int_floor(VALUE num, int ndigits) if (neg) x = -x; return LONG2NUM(x); } - if (RB_FLOAT_TYPE_P(f)) { - /* then int_pow overflow */ - return INT2FIX(0); + else { + bool neg = int_neg_p(num); + if (neg) num = rb_int_minus(rb_int_plus(rb_int_uminus(num), f), INT2FIX(1)); + num = rb_int_mul(rb_int_div(num, f), f); + if (neg) num = rb_int_uminus(num); + return num; } - return rb_int_minus(num, rb_int_modulo(num, f)); } static VALUE -- cgit v1.2.3