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Corrected unspecified behavior of corner cases in fp.min/fp.max.

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Partially addresses #68.
This commit is contained in:
Christoph M. Wintersteiger 2015-10-06 19:45:05 +01:00
parent 6e852762ba
commit 8a026c355f
10 changed files with 211 additions and 55 deletions
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66
src/ast/rewriter/fpa_rewriter.cpp
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@ -93,6 +93,10 @@ br_status fpa_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr * con
case OP_FPA_TO_IEEE_BV: SASSERT(num_args == 1); st = mk_to_ieee_bv(f, args[0], result); break;
case OP_FPA_TO_REAL: SASSERT(num_args == 1); st = mk_to_real(args[0], result); break;
case OP_FPA_INTERNAL_MIN_UNSPECIFIED:
case OP_FPA_INTERNAL_MAX_UNSPECIFIED:
SASSERT(num_args == 0); st = BR_FAILED; break;
case OP_FPA_INTERNAL_TO_UBV_UNSPECIFIED:
SASSERT(num_args == 0); st = mk_to_ubv_unspecified(f, result); break;
case OP_FPA_INTERNAL_TO_SBV_UNSPECIFIED:
@ -422,29 +426,24 @@ br_status fpa_rewriter::mk_min(expr * arg1, expr * arg2, expr_ref & result) {
result = arg2;
return BR_DONE;
}
if (m_util.is_nan(arg2)) {
else if (m_util.is_nan(arg2)) {
result = arg1;
return BR_DONE;
}
if (m_util.is_zero(arg1) && m_util.is_zero(arg2)) {
result = arg2;
return BR_DONE;
scoped_mpf v1(m_fm), v2(m_fm);
if (m_util.is_numeral(arg1, v1) && m_util.is_numeral(arg2, v2)) {
if (m_fm.is_zero(v1) && m_fm.is_zero(v2) && m_fm.sgn(v1) != m_fm.sgn(v2))
return BR_FAILED; // Result could be +zero or -zero.
else {
scoped_mpf r(m_fm);
m_fm.minimum(v1, v2, r);
result = m_util.mk_value(r);
return BR_DONE;
}
}
result = m().mk_ite(mk_eq_nan(arg1),
arg2,
m().mk_ite(mk_eq_nan(arg2),
arg1,
// min(-0.0, +0.0) = min(+0.0, -0.0) = +0.0
m().mk_ite(m().mk_and(m_util.mk_is_zero(arg1), m_util.mk_is_zero(arg2),
m().mk_not(m().mk_eq(m_util.mk_is_positive(arg1), m_util.mk_is_positive(arg2)))),
m_util.mk_pzero(m().get_sort(arg1)),
m().mk_ite(m().mk_and(m_util.mk_is_zero(arg1), m_util.mk_is_zero(arg2)),
arg2,
m().mk_ite(m_util.mk_lt(arg1, arg2),
arg1,
arg2)))));
return BR_REWRITE_FULL;
return BR_FAILED;
}
br_status fpa_rewriter::mk_max(expr * arg1, expr * arg2, expr_ref & result) {
@ -452,29 +451,24 @@ br_status fpa_rewriter::mk_max(expr * arg1, expr * arg2, expr_ref & result) {
result = arg2;
return BR_DONE;
}
if (m_util.is_nan(arg2)) {
else if (m_util.is_nan(arg2)) {
result = arg1;
return BR_DONE;
}
if (m_util.is_zero(arg1) && m_util.is_zero(arg2)) {
result = arg2;
return BR_DONE;
scoped_mpf v1(m_fm), v2(m_fm);
if (m_util.is_numeral(arg1, v1) && m_util.is_numeral(arg2, v2)) {
if (m_fm.is_zero(v1) && m_fm.is_zero(v2) && m_fm.sgn(v1) != m_fm.sgn(v2))
return BR_FAILED; // Result could be +zero or -zero.
else {
scoped_mpf r(m_fm);
m_fm.maximum(v1, v2, r);
result = m_util.mk_value(r);
return BR_DONE;
}
}
result = m().mk_ite(mk_eq_nan(arg1),
arg2,
m().mk_ite(mk_eq_nan(arg2),
arg1,
// max(-0.0, +0.0) = max(+0.0, -0.0) = +0.0
m().mk_ite(m().mk_and(m_util.mk_is_zero(arg1), m_util.mk_is_zero(arg2),
m().mk_not(m().mk_eq(m_util.mk_is_positive(arg1), m_util.mk_is_positive(arg2)))),
m_util.mk_pzero(m().get_sort(arg1)),
m().mk_ite(m().mk_and(m_util.mk_is_zero(arg1), m_util.mk_is_zero(arg2)),
arg2,
m().mk_ite(m_util.mk_gt(arg1, arg2),
arg1,
arg2)))));
return BR_REWRITE_FULL;
return BR_FAILED;
}
br_status fpa_rewriter::mk_fma(expr * arg1, expr * arg2, expr * arg3, expr * arg4, expr_ref & result) {