Module stack 

Stack scheduling for EVM code generation.

This module handles the translation from MIR’s SSA values to EVM’s stack-based model. The key abstraction is StackModel, which tracks which MIR values are at which stack depths.

Submodules

• model: Core stack model tracking value positions
• scheduler: Stack scheduler for generating DUP/SWAP sequences
• shuffler: Optimal stack layout transitions (backward analysis)
• spill: Spill management for values beyond depth 16

Modules

shuffler

Stack shuffler for optimal stack layout transitions.

Structs

BlockStackLayout

Represents a stack layout for a block - the values that should be on the stack when entering or exiting a block, from top to bottom.

LayoutAnalysis

Computes the ideal entry layout for an instruction given the desired exit layout.

ShuffleResult

Result of a shuffle operation.

SpillManager

Manages spill slots for values that cannot fit on the stack.

SpillSlot

A slot in memory where a spilled value is stored.

StackModel

Represents the current state of the EVM stack.

StackScheduler

Stack scheduler that generates stack manipulation operations.

StackShuffler

The stack shuffler transforms a source stack layout to a target layout.

Enums

ScheduledOp

A scheduled operation to emit.

StackOp

Operations to emit for stack manipulation.

TargetSlot

Represents a slot in the target layout.

Functions

combine_stack_layouts

Computes a common stack layout for multiple incoming edges at a merge point.

estimate_shuffle_cost

Computes the shuffle cost from a source layout to a target layout. This estimates the number of DUP/SWAP/POP operations needed.

ideal_binary_op_entry

Computes the ideal pre-layout for a binary operation.

ideal_operand_layout

Creates an ideal layout for preparing multiple operands.

ideal_unary_op_entry

Computes the ideal pre-layout for a unary operation.

is_freely_generable

Checks if a value can be freely generated (doesn’t need to be on stack).