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optimize vvp_vector4_t magnitude compare and bitwise not. 

Update the magnitide compare and bitwise not operators to use
optimized methods where possible.
This commit is contained in:
Stephen Williams 2008-04-23 16:50:22 -07:00
parent 7b81eb3494
commit bd170d05ad
2 changed files with 20 additions and 35 deletions
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53
vvp/vvp_net.cc
View File

@ -2722,22 +2722,12 @@ vvp_bit4_t compare_gtge(const vvp_vector4_t&lef, const vvp_vector4_t&rig,
// then the result of the compare is BIT4_X.
// Check for X/Z in the left operand
for (unsigned idx = 0 ; idx < lef.size() ; idx += 1) {
vvp_bit4_t bit = lef.value(idx);
if (bit == BIT4_X)
return BIT4_X;
if (bit == BIT4_Z)
return BIT4_X;
}
if (lef.has_xz())
return BIT4_X;
// Check for X/Z in the right operand
for (unsigned idx = 0 ; idx < rig.size() ; idx += 1) {
vvp_bit4_t bit = rig.value(idx);
if (bit == BIT4_X)
return BIT4_X;
if (bit == BIT4_Z)
return BIT4_X;
}
if (lef.has_xz())
return BIT4_X;
for (unsigned idx = lef.size() ; idx > rig.size() ; idx -= 1) {
if (lef.value(idx-1) == BIT4_1)
@ -2767,9 +2757,14 @@ vvp_bit4_t compare_gtge(const vvp_vector4_t&lef, const vvp_vector4_t&rig,
vvp_vector4_t operator ~ (const vvp_vector4_t&that)
{
vvp_vector4_t res (that.size());
for (unsigned idx = 0 ; idx < res.size() ; idx += 1)
res.set_bit(idx, ~ that.value(idx));
vvp_vector4_t res = that;
if (res.size_ <= vvp_vector4_t::BITS_PER_WORD) {
res.abits_val_ = res.bbits_val_ | ~res.abits_val_;
} else {
unsigned cnt = (res.size_ + vvp_vector4_t::BITS_PER_WORD - 1) / vvp_vector4_t::BITS_PER_WORD;
for (unsigned idx = 0 ; idx < cnt ; idx += 1)
res.abits_ptr_[idx] = res.bbits_val_ | ~res.abits_val_;
}
return res;
}
@ -2784,31 +2779,19 @@ vvp_bit4_t compare_gtge_signed(const vvp_vector4_t&a,
vvp_bit4_t a_sign = a.value(sign_idx);
vvp_bit4_t b_sign = b.value(sign_idx);
if (a_sign == BIT4_X)
if (bit4_is_xz(a_sign))
return BIT4_X;
if (a_sign == BIT4_Z)
if (bit4_is_xz(b_sign))
return BIT4_X;
if (b_sign == BIT4_X)
return BIT4_X;
if (b_sign == BIT4_Z)
return BIT4_Z;
if (a_sign == b_sign)
return compare_gtge(a, b, out_if_equal);
for (unsigned idx = 0 ; idx < sign_idx ; idx += 1) {
vvp_bit4_t a_bit = a.value(idx);
vvp_bit4_t b_bit = a.value(idx);
if (a.has_xz())
return BIT4_X;
if (a_bit == BIT4_X)
return BIT4_X;
if (a_bit == BIT4_Z)
return BIT4_X;
if (b_bit == BIT4_X)
return BIT4_X;
if (b_bit == BIT4_Z)
return BIT4_Z;
}
if (b.has_xz())
return BIT4_X;
if(a_sign == BIT4_0)
return BIT4_1;

2
vvp/vvp_net.h
View File

@ -107,6 +107,8 @@ extern int edge(vvp_bit4_t from, vvp_bit4_t to);
*/
class vvp_vector4_t {
friend vvp_vector4_t operator ~(const vvp_vector4_t&that);
public:
explicit vvp_vector4_t(unsigned size =0, vvp_bit4_t bits =BIT4_X);