Module memory_utils

An analysis to compute symbols that escape out from a function. This could be into another function, or via ptr_to_int etc. Any transformations involving such symbols are unsafe.

Enums

EscapedSymbols

ReferredSymbols

Provides Symbols, both Symbol::Locals and Symbol::Args, reachable from a certain Value via chain of InstOp::GetElemPtr (GEP) instructions or via InstOp::IntToPtr and InstOp::PtrToInt instruction patterns specific to references, both referencing (&) and dereferencing (*), and raw pointers, via __addr_of.

Symbol

Constants

ESCAPED_SYMBOLS_NAME

Functions

combine_indices

Combine a series of GEPs into one.

compute_escaped_symbols

compute_escaped_symbols_pass

create_escaped_symbols_pass

get_gep_referred_symbols

Get Symbols, both Symbol::Locals and Symbol::Args, reachable from the val via chain of InstOp::GetElemPtr (GEP) instructions. A val can, via GEP instructions, refer indirectly to none, or one or more symbols.

get_gep_symbol

get_loaded_ptr_values

Pointers that may possibly be loaded from the instruction inst.

get_loaded_symbols

Symbols that may possibly, directly or indirectly, be loaded from the instruction inst.

get_memory_offsets

Given a memory pointer instruction, compute the offset of indexed element, for each symbol that it may alias to. If for any symbol we can’t compute it, return None.

get_referred_symbol

Return Symbol referred by val if there is exactly one symbol referred, or None if there are no Symbols referred or if there is more then one referred.

get_referred_symbols

Get Symbols, both Symbol::Locals and Symbol::Args, reachable from the val via chain of InstOp::GetElemPtr (GEP) instructions or via InstOp::IntToPtr and InstOp::PtrToInt instruction patterns specific to references, both referencing (&) and dereferencing (*), and raw pointers, via __addr_of. A val can, via these instructions, refer indirectly to none, or one or more symbols.

get_stored_ptr_values

Pointers that may possibly be stored to the instruction inst.

get_stored_symbols

Symbols that may possibly, directly or indirectly, be stored to the instruction inst.

may_alias

Can memory ranges [val1, val1+len1] and [val2, val2+len2] overlap? Conservatively returns true if cannot statically determine.

must_alias

Are memory ranges [val1, val1+len1] and [val2, val2+len2] exactly the same? Conservatively returns false if cannot statically determine.

pointee_size

For a pointer argument ptr_val, what’s the size of its pointee.