diff options
Diffstat (limited to 'gcc/vector-builder.h')
| -rw-r--r-- | gcc/vector-builder.h | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/gcc/vector-builder.h b/gcc/vector-builder.h index ae30b3bb..0edd6f5 100644 --- a/gcc/vector-builder.h +++ b/gcc/vector-builder.h @@ -68,6 +68,10 @@ along with GCC; see the file COPYING3. If not see given integral_p (ELT1) && integral_p (ELT2). There is no fixed choice of StepType. + T apply_step (T base, unsigned int factor, StepType step) const; + + Return a vector element with the value BASE + FACTOR * STEP. + bool can_elide_p (T elt) const; Return true if we can drop element ELT, even if the retained @@ -91,6 +95,7 @@ public: unsigned int nelts_per_pattern () const { return m_nelts_per_pattern; } unsigned int encoded_nelts () const; bool encoded_full_vector_p () const; + T elt (unsigned int) const; void finalize (); @@ -163,6 +168,38 @@ vector_builder<T, Derived>::new_vector (unsigned int full_nelts, this->truncate (0); } +/* Return the value of vector element I, which might or might not be + encoded explicitly. */ + +template<typename T, typename Derived> +T +vector_builder<T, Derived>::elt (unsigned int i) const +{ + /* This only makes sense if the encoding has been fully populated. */ + gcc_checking_assert (encoded_nelts () <= this->length ()); + + /* First handle elements that are already present in the underlying + vector, regardless of whether they're part of the encoding or not. */ + if (i < this->length ()) + return (*this)[i]; + + /* Identify the pattern that contains element I and work out the index of + the last encoded element for that pattern. */ + unsigned int pattern = i % m_npatterns; + unsigned int count = i / m_npatterns; + unsigned int final_i = encoded_nelts () - m_npatterns + pattern; + T final = (*this)[final_i]; + + /* If there are no steps, the final encoded value is the right one. */ + if (m_nelts_per_pattern <= 2) + return final; + + /* Otherwise work out the value from the last two encoded elements. */ + T prev = (*this)[final_i - m_npatterns]; + return derived ()->apply_step (final, count - 2, + derived ()->step (prev, final)); +} + /* Change the encoding to NPATTERNS patterns of NELTS_PER_PATTERN each, but without changing the underlying vector. */ |