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Safe handling of C left shift.

This commit is contained in:
steve 2005-08-29 04:46:52 +00:00
parent 7c19eb51e7
commit 70f146924a
1 changed files with 29 additions and 11 deletions
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40
vvp/vvp_net.cc
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@ -16,7 +16,7 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ident "$Id: vvp_net.cc,v 1.43 2005/08/27 03:28:16 steve Exp $"
#ident "$Id: vvp_net.cc,v 1.44 2005/08/29 04:46:52 steve Exp $"
# include "config.h"
# include "vvp_net.h"
@ -207,20 +207,25 @@ vvp_vector4_t::vvp_vector4_t(const vvp_vector4_t&that,
unsigned ptr = adr / BITS_PER_WORD;
unsigned off = adr % BITS_PER_WORD;
unsigned noff = BITS_PER_WORD - off;
unsigned long lmask = (1 << 2*off) - 1;
unsigned long lmask = (1UL << 2UL*off) - 1UL;
unsigned trans = 0;
unsigned dst = 0;
while (trans < wid) {
// The low bits of the result.
bits_ptr_[dst] = (that.bits_ptr_[ptr] & ~lmask) >> 2*off;
bits_ptr_[dst] = (that.bits_ptr_[ptr] & ~lmask) >> 2UL*off;
trans += noff;
if (trans >= wid)
break;
ptr += 1;
bits_ptr_[dst] |= (that.bits_ptr_[ptr] & lmask) << 2*noff;
trans += off;
// The high bits of the result. Skip this if the
// source and destination are perfectly aligned.
if (noff != BITS_PER_WORD) {
ptr += 1;
bits_ptr_[dst] |= (that.bits_ptr_[ptr]&lmask) << 2*noff;
trans += off;
}
dst += 1;
}
@ -349,7 +354,7 @@ void vvp_vector4_t::set_vec(unsigned adr, const vvp_vector4_t&that)
job by some shifting, masking and OR. */
unsigned long lmask = (1UL << 2UL*adr) - 1;
unsigned long hmask = (1 << 2UL*(adr+that.size_)) - 1;
unsigned long hmask = (1UL << 2UL*(adr+that.size_)) - 1;
unsigned long mask = hmask & ~lmask;
bits_val_ =
@ -361,15 +366,21 @@ void vvp_vector4_t::set_vec(unsigned adr, const vvp_vector4_t&that)
unsigned long dptr = adr / BITS_PER_WORD;
unsigned long doff = adr % BITS_PER_WORD;
unsigned long lmask = (1UL<<2UL*doff) - 1;
unsigned long hmask = (1UL << 2UL*(doff+that.size_)) - 1;
unsigned long lmask = (1UL << 2UL*doff) - 1;
unsigned long hshift = doff+that.size_;
unsigned long hmask;
if (hshift >= BITS_PER_WORD)
hmask = -1UL;
else
hmask = (1UL << 2*hshift) - 1UL;
unsigned long mask = hmask & ~lmask;
bits_ptr_[dptr] =
(bits_ptr_[dptr] & ~mask)
| ((that.bits_val_ << 2UL*doff) & mask);
if (doff + that.size_ > BITS_PER_WORD) {
if ((doff + that.size_) > BITS_PER_WORD) {
unsigned tail = doff + that.size_ - BITS_PER_WORD;
mask = (1UL << 2UL*tail) - 1;
@ -450,11 +461,15 @@ bool vvp_vector4_t::eeq(const vvp_vector4_t&that) const
if (size_ != that.size_)
return false;
if (size_ <= BITS_PER_WORD) {
if (size_ < BITS_PER_WORD) {
unsigned long mask = (1UL << 2UL * size_) - 1;
return (bits_val_&mask) == (that.bits_val_&mask);
}
if (size_ == BITS_PER_WORD) {
return bits_val_ == that.bits_val_;
}
unsigned words = size_ / BITS_PER_WORD;
for (unsigned idx = 0 ; idx < words ; idx += 1) {
if (bits_ptr_[idx] != that.bits_ptr_[idx])
@ -1639,6 +1654,9 @@ vvp_bit4_t compare_gtge_signed(const vvp_vector4_t&a,
/*
* $Log: vvp_net.cc,v $
* Revision 1.44 2005/08/29 04:46:52 steve
* Safe handling of C left shift.
*
* Revision 1.43 2005/08/27 03:28:16 steve
* Be more cautios about accessing out-of-range bits.
*