hlstl

High Level Synthesis Template Library

Directory Structure

common/
common/assert.hpp - Assertion variants and related helpers. Automatically enabled during CSIM Macros:

• ASSERT(condition, message) Prints message and asserts if condition is false

• ASSERT_IF(condition_when_to_check_assertion,assertion_condition,message) When <condition_when_to_check_assertion> is true, check <assertion_condition> and print if <assertion_condition> fails

• DO_PRAGMA(x) Place a pragma on the current line Expands macros that are specified in x

• INFO(message) Print a message

• UNIMPLEMENTED() Assert if this line of code is tripped

• UNIMPLEMENTED_QUIET(messsage) If this line is tripped, print a message but don't assert

common/type_manip.hpp - Convenience helpers to manipulate, extract, and modify types

Functions:

• IsPowerOfTwo Returns true if # is power of 2

• BitsNeededToStore Calculates the minimum number of bits that are needed to store the value held in integral_value

• reverse_bit_groupings Given a bit group size, reverse a word by bit groupings Similar to reversing endianess, but bit groupings not restricted to 8 bits

• reverse_endianess *Reverses the endianess of a word Specialization of reverse_bit_groupings where a bit group is 8 bits.

• CountKeepBits Returns the number of high bits in a keep field

• CreateNBitMask Create a mask with N bits set high (container type can be specified)

• CreateNByteMask Creates a mask of bytes, N bytes wide (return container type can be specified)

• CreateTypeBitMask Create a bit mask of the same size as the specified type

• ExtractSmallerTypeFromIntegralType Given a larger word, extract some smaller type from that word at a given offset

• ByteAddressableToWordAddressable Given a byte address, convert it to a word address, where the word size is caller specified

• ByteAddressableToSubWordAddressable Given a byte address, extract that part of the address that is used to index into subwords of a larger type e.g. if given a byte address, and the memory bus is for 8 byte words, then the sub-word address is to address the 8 bytes of that word (i.e. the first 3 bits of the addr)

common/hls_types.hpp - Convenience helpers to define, types, derive types, inspect, and deduce types

Functions/Types:

• using hls_bool_t = ap_uint<1>;

• using hls_int_t = ap_int<32>;

• using hls_uint_t = ap_uint<32>;

• ReadVarIntoApInt Given a base type with a value, store that value in an ap_u?int container (not a type cast!)

• ReadApIntToVar Given an ap_u?int container with some value encoded as a base type, return that value in that base type (not a type cast!)

• hls_stream_flit_t Given an hls stream type, derive a type that is the same type as the flit of that stream

• hls_stream_data_t Given an hls stream type, derive a type that is the same type as the data field of that stream

• TYPE_WIDTH_IN_BITS Given a type, return its width in bits

• ComputeFieldLengthInBytes Given a type, return its width in bits

• HLS_STREAM_DATA_WIDTH Given an hls stream type, return it's data field size in bits

• FIELD_BUFFER_FITS_IN_STREAM Given an hls stream type and another type, T, check to see if T can fit inside of the data field of the hls stream type

For now this library contains the source headers of a handful of helper functions/types.