Data Fields | |
| rtx | rtl |
| rtx | src |
| struct table_elt * | src_elt |
| unsigned | src_hash |
| unsigned | dest_hash |
| rtx | inner_dest |
| char | src_in_memory |
| char | src_volatile |
Detailed Description
CSE processing for one instruction.
Most "true" common subexpressions are mostly optimized away in GIMPLE, but the few that "leak through" are cleaned up by cse_insn, and complex addressing modes are often formed here.
The main function is cse_insn, and between here and that function a couple of helper functions is defined to keep the size of cse_insn within reasonable proportions.
Data is shared between the main and helper functions via STRUCT SET, that contains all data related for every set in the instruction that is being processed.
Note that cse_main processes all sets in the instruction. Most passes in GCC only process simple SET insns or single_set insns, but CSE processes insns with multiple sets as well. Data on one SET contained in the instruction.
Field Documentation
| unsigned set::dest_hash |
Hash value for the SET_DEST.
| rtx set::inner_dest |
The SET_DEST, with SUBREG, etc., stripped.
| rtx set::rtl |
The SET rtx itself.
| rtx set::src |
The SET_SRC of the rtx (the original value, if it is changing).
Referenced by try_back_substitute_reg().
| struct table_elt* set::src_elt |
The hash-table element for the SET_SRC of the SET.
| unsigned set::src_hash |
Hash value for the SET_SRC.
| char set::src_in_memory |
Nonzero if the SET_SRC is in memory.
| char set::src_volatile |
Nonzero if the SET_SRC contains something whose value cannot be predicted and understood.
The documentation for this struct was generated from the following file:
