Data Structures
struct	[struct].sig

Public Types
enum	long_mul_row_part { HIGH_PART , LOW_PART }

Data Fields
enum long_mul_row::long_mul_row_part	part
tree_code	outer
unsigned char	count
struct	sig [LONG_MUL_MAX_SUMMANDS]
bool(*)	extra_check (const vec< long_mul_summand > &, gimple *)

Detailed Description

One row of the long-multiply variant table.  COUNT is how many entries
of SIG carry the row's signature (2 to LONG_MUL_MAX_SUMMANDS); a row
with fewer summands leaves the remaining SIG entries zero-initialized.
Those zeros are not a terminator -- {LMK_MUL_HIHI, LMX_NONE} is itself a
valid signature -- so long_mul_signature_matches is bounded by COUNT,
never by a sentinel entry.