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Fixed bug in to_fp/to_fp_unsigned. Thanks to Florian Schanda for reporting this bug.

This commit is contained in:
Christoph M. Wintersteiger 2018-04-06 17:08:29 +01:00
parent 287c6f08e1
commit be4edddd2b

View file

@ -2845,7 +2845,7 @@ void fpa2bv_converter::mk_to_fp_signed(func_decl * f, unsigned num, expr * const
expr_ref is_neg(m), x_abs(m), neg_x(m);
is_neg_bit = m_bv_util.mk_extract(bv_sz - 1, bv_sz - 1, x);
is_neg = m.mk_eq(is_neg_bit, bv1_1);
neg_x = m_bv_util.mk_bv_neg(x);
neg_x = m_bv_util.mk_bv_neg(x); // overflow problem?
x_abs = m.mk_ite(is_neg, neg_x, x);
dbg_decouple("fpa2bv_to_fp_signed_is_neg", is_neg);
// x_abs has an extra bit in the front.
@ -2882,11 +2882,13 @@ void fpa2bv_converter::mk_to_fp_signed(func_decl * f, unsigned num, expr * const
SASSERT(is_well_sorted(m, lz));
}
SASSERT(m_bv_util.get_bv_size(sig_4) == sig_sz);
dbg_decouple("fpa2bv_to_fp_signed_sig_4", sig_4);
expr_ref s_exp(m), exp_rest(m);
s_exp = m_bv_util.mk_bv_sub(m_bv_util.mk_numeral(bv_sz - 2, bv_sz), lz);
// s_exp = (bv_sz-2) + (-lz) signed
SASSERT(m_bv_util.get_bv_size(s_exp) == bv_sz);
dbg_decouple("fpa2bv_to_fp_signed_s_exp", s_exp);
unsigned exp_sz = ebits + 2; // (+2 for rounder)
exp_2 = m_bv_util.mk_extract(exp_sz - 1, 0, s_exp);
@ -2907,10 +2909,9 @@ void fpa2bv_converter::mk_to_fp_signed(func_decl * f, unsigned num, expr * const
mk_max_exp(exp_sz, max_exp);
max_exp_bvsz = m_bv_util.mk_zero_extend(bv_sz - exp_sz, max_exp);
exp_too_large = m_bv_util.mk_ule(m_bv_util.mk_bv_add(
max_exp_bvsz,
m_bv_util.mk_numeral(1, bv_sz)),
s_exp);
exp_too_large = m_bv_util.mk_sle(
m_bv_util.mk_bv_add(max_exp_bvsz, m_bv_util.mk_numeral(1, bv_sz)),
s_exp);
zero_sig_sz = m_bv_util.mk_numeral(0, sig_sz);
sig_4 = m.mk_ite(exp_too_large, zero_sig_sz, sig_4);
exp_2 = m.mk_ite(exp_too_large, max_exp, exp_2);
@ -3040,7 +3041,7 @@ void fpa2bv_converter::mk_to_fp_unsigned(func_decl * f, unsigned num, expr * con
mk_max_exp(exp_sz, max_exp);
max_exp_bvsz = m_bv_util.mk_zero_extend(bv_sz - exp_sz, max_exp);
exp_too_large = m_bv_util.mk_ule(m_bv_util.mk_bv_add(
exp_too_large = m_bv_util.mk_sle(m_bv_util.mk_bv_add(
max_exp_bvsz,
m_bv_util.mk_numeral(1, bv_sz)),
s_exp);