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* buffer_is_zero: use vector optimizations if possiblePeter Lieven2013-03-261-0/+5
| | | | | | | | | | | performance gain on SSE2 is approx. 20-25%. altivec is not tested. performance for unsigned long arithmetic is unchanged. Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Orit Wasserman <owasserm@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
* cutils: add a function to find non-zero content in a bufferPeter Lieven2013-03-261-0/+55
| | | | | | | | | | | | | | | | | | | | | this adds buffer_find_nonzero_offset() which is a SSE2/Altivec optimized function that searches for non-zero content in a buffer. the function starts full unrolling only after the first few chunks have been checked one by one. analyzing real memory page data has revealed that non-zero pages are non-zero within the first 256-512 bits in most cases. as this function is also heavily used to check for zero memory pages this tweak has been made to avoid the high setup costs of the fully unrolled check for non-zero pages. due to the optimizations used in the function there are restrictions on buffer address and search length. the function can_use_buffer_find_nonzero_content() can be used to check if the function can be used safely. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Juan Quintela <quintela@redhat.com>
* cutils: unsigned int parsing functionsEduardo Habkost2013-02-041-0/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are lots of duplicate parsing code using strto*() in QEMU, and most of that code is broken in one way or another. Even the visitors code have duplicate integer parsing code[1]. This introduces functions to help parsing unsigned int values: parse_uint() and parse_uint_full(). Parsing functions for signed ints and floats will be submitted later. parse_uint_full() has all the checks made by opts_type_uint64() at opts-visitor.c: - Check for NULL (returns -EINVAL) - Check for negative numbers (returns -EINVAL) - Check for empty string (returns -EINVAL) - Check for overflow or other errno values set by strtoll() (returns -errno) - Check for end of string (reject invalid characters after number) (returns -EINVAL) parse_uint() does everything above except checking for the end of the string, so callers can continue parsing the remainder of string after the number. Unit tests included. [1] string-input-visitor.c:parse_int() could use the same parsing code used by opts-visitor.c:opts_type_int(), instead of duplicating that logic. Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
* build: move libqemuutil.a components to util/Paolo Bonzini2013-01-121-0/+325
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>