Owned unspillable and unevictable temporary register with RAII semantics. More...

#include <ScratchReg.hpp>

Public Member Functions
	ScratchReg (CompilerBase *compiler)
	Constructor, no register.

bool	has_reg () const
	Whether a register is currently allocated.

AsmReg	cur_reg () const
	The allocated register.

AsmReg	alloc_specific (AsmReg reg)
	Allocate a specific register.

AsmReg	alloc_gp ()
	Allocate a general-purpose register.

AsmReg	alloc (RegBank bank)
	Allocate register in the specified bank.

AsmReg	release ()
	Release register, marking it as unused; returns the register.

void	reset ()
	Deallocate register.

	CompilerBase (Adaptor *adaptor)
	Initialize a CompilerBase, should be called by the derived classes.

Derived *	derived ()
	shortcut for casting to the Derived class so that overloading works

bool	compile ()
	Compile the functions returned by Adaptor::funcs.

void	reset ()
	Reset any leftover data from the previous compilation such that it will not affect the next compilation.

CCAssigner *	cur_cc_assigner ()
	Get CCAssigner for current function.

void	release_assignment (ValLocalIdx local_idx, ValueAssignment *)
	Release an assignment when reference count drops to zero, either frees the assignment immediately or delays free to the end of the live range.

void	init_variable_ref (ValLocalIdx local_idx, u32 var_ref_data)
	Init a variable-ref assignment.

void	init_variable_ref (IRValueRef value, u32 var_ref_data)
	Init a variable-ref assignment.

void	prologue_assign_arg (CCAssigner *cc_assigner, u32 arg_idx, IRValueRef arg, u32 align=1, bool allow_split=false)
	Assign function argument in prologue.

AsmReg	gval_as_reg (GenericValuePart &gv)
	Get generic value part into a single register, evaluating expressions and materializing immediates as required.

AsmReg	gval_as_reg_reuse (GenericValuePart &gv, ScratchReg &dst)
	Like gval_as_reg; if the GenericValuePart owns a reusable register (either a ScratchReg, possibly due to materialization, or a reusable ValuePartRef), store it in dst.

AsmReg	gval_as_reg_reuse (GenericValuePart &gv, ValuePart &dst)
	Like gval_as_reg; if the GenericValuePart owns a reusable register (either a ScratchReg, possibly due to materialization, or a reusable ValuePartRef), store it in dst.

void	label_place (Label label)
	Convenience function to place a label at the current position.

Stack Slots
i32	allocate_stack_slot (u32 size)
	Allocate a static stack slot.

void	free_stack_slot (u32 slot, u32 size)
	Free a static stack slot.

Value References
ValueRef	val_ref (IRValueRef value)
	Get a using reference to a value.

std::pair< ValueRef, ValuePartRef >	val_ref_single (IRValueRef value)
	Get a using reference to a single-part value and provide direct access to the only part.

ValueRef	result_ref (IRValueRef value)
	Get a defining reference to a value.

std::pair< ValueRef, ValuePartRef >	result_ref_single (IRValueRef value)
	Get a defining reference to a single-part value and provide direct access to the only part.

ValueRef	result_ref_alias (IRValueRef dst, ValueRef &&src)
	Make dst an alias for src, which must be a non-constant value with an identical part configuration.

ValueRef	result_ref_stack_slot (IRValueRef value, AssignmentPartRef base, i32 off)
	Initialize value as a pointer into a stack variable (i.e., a value allocated from cur_static_allocas() or similar) with an offset.

Low-Level Assignment Register Handling
Reg	select_reg (RegBank bank)
	Select an available register, evicting loaded values if needed.

void	reload_to_reg (AsmReg dst, AssignmentPartRef ap)
	Reload a value part from memory or recompute variable address.

void	allocate_spill_slot (AssignmentPartRef ap)
	Allocate a stack slot for an assignment.

void	spill (AssignmentPartRef ap)
	Ensure the value is spilled in its stack slot (except variable refs).

void	evict (AssignmentPartRef ap)
	Evict the value from its register, spilling if needed, and free register.

void	evict_reg (Reg reg)
	Evict the value from the register, spilling if needed, and free register.

void	free_reg (Reg reg)
	Free the register. Requires that the contained value is already spilled.

High-Level Branch Generation
void	generate_uncond_branch (IRBlockRef target)
	Generate an unconditional branch at the end of a basic block.

void	generate_cond_branch (Jump jmp, IRBlockRef true_target, IRBlockRef false_target)
	Generate an conditional branch at the end of a basic block.

void	generate_switch (ScratchReg &&cond, u32 width, IRBlockRef default_block, std::span< const std::pair< u64, IRBlockRef > > cases)
	Generate a switch at the end of a basic block.

Low-Level Branch Primitives
The general flow of using these low-level primitive is: spill_before_branch() begin_branch_region() One or more calls to generate_branch_to_block() end_branch_region() release_spilled_regs()
RegisterFile::RegBitSet	spill_before_branch (bool force_spill=false)
	Spill values that need to be spilled for later blocks.

void	release_spilled_regs (typename RegisterFile::RegBitSet)
	Free registers marked by spill_before_branch().

void	release_regs_after_return ()
	When reaching a point in the function where no other blocks will be reached anymore, use this function to release register assignments after the end of that block so the compiler does not accidentally use registers which don't contain any values.

void	begin_branch_region ()
	Indicate beginning of region where value-state must not change.

void	end_branch_region ()
	Indicate end of region where value-state must not change.

void	generate_branch_to_block (Jump jmp, IRBlockRef target, bool needs_split, bool last_inst)
	Generate a branch to a basic block; execution continues afterwards.

bool	branch_needs_split (IRBlockRef target)
	Whether branch to a block requires additional instructions and therefore a direct jump to the block is not possible.

Public Attributes
u32	frame_size
	The current size of the stack frame.

bool	has_dynamic_alloca
	Whether the stack frame might have dynamic alloca.

bool	is_leaf_function
	Whether the function is guaranteed to be a leaf function.

bool	generated_call
	Whether the function actually includes a call.

bool	frame_used
	Whether the stack frame is used.

util::SmallVector< i32, 16 >	fixed_free_lists [5]
	Free-Lists for 1/2/4/8/16 sized allocations.

std::unordered_map< u32, std::vector< i32 > >	dynamic_free_lists
	Free-Lists for all other sizes.

bool	generating_branch
	Whether we are currently in the middle of generating branch-related code and therefore must not change any value-related state.

Detailed Description

template<IRAdaptor Adaptor, typename Derived, CompilerConfig Config = CompilerConfigDefault>
struct tpde::CompilerBase< Adaptor, Derived, Config >::ScratchReg

Owned unspillable and unevictable temporary register with RAII semantics.

Definition at line 10 of file ScratchReg.hpp.

Member Function Documentation

◆ alloc()

template<IRAdaptor Adaptor, typename Derived, CompilerConfig Config>

CompilerBase< Adaptor, Derived, Config >::AsmReg tpde::CompilerBase< Adaptor, Derived, Config >::ScratchReg::alloc ( RegBank bank )

Allocate register in the specified bank.

Does nothing if it holds a register in the specified bank. Evicts a register if required.

Definition at line 106 of file ScratchReg.hpp.

◆ compile()

bool tpde::CompilerBase< Adaptor, Derived, Config >::compile ( )

Compile the functions returned by Adaptor::funcs.

Warning: If you intend to call this multiple times, you must call reset in-between the calls.

Returns: Whether the compilation was successful

Definition at line 334 of file CompilerBase.hpp.

◆ generate_branch_to_block()

void tpde::CompilerBase< Adaptor, Derived, Config >::generate_branch_to_block	(	Jump	jmp,
		IRBlockRef	target,
		bool	needs_split,
		bool	last_inst )

Generate a branch to a basic block; execution continues afterwards.

Multiple calls to this function can be used to build conditional branches.

Template Parameters

Jump	Target-defined Jump type (e.g., CompilerX64::Jump).

Parameters

needs_split	Result of branch_needs_split(); pass false for an unconditional branch.
last_inst	Whether fall-through to target is possible.

Definition at line 545 of file CompilerBase.hpp.

◆ generate_switch()

void tpde::CompilerBase< Adaptor, Derived, Config >::generate_switch	(	ScratchReg &&	cond,
		u32	width,
		IRBlockRef	default_block,
		std::span< const std::pair< u64, IRBlockRef > >	cases )

Generate a switch at the end of a basic block.

Only the lowest bits of the condition are considered. The condition must be a general-purpose register. The cases must be sorted and every case value must appear at most once.

Definition at line 491 of file CompilerBase.hpp.

◆ generate_uncond_branch()

void tpde::CompilerBase< Adaptor, Derived, Config >::generate_uncond_branch ( IRBlockRef target )

Generate an unconditional branch at the end of a basic block.

No further instructions must follow. If target is the next block in the block order, the branch is omitted.

Definition at line 479 of file CompilerBase.hpp.

◆ prologue_assign_arg()

void tpde::CompilerBase< Adaptor, Derived, Config >::prologue_assign_arg	(	CCAssigner *	cc_assigner,
		u32	arg_idx,
		IRValueRef	arg,
		u32	align = 1,
		bool	allow_split = false )

Assign function argument in prologue.

align can be used to increase the minimal stack alignment of the first part of the argument. If allow_split is set, the argument can be passed partially in registers, otherwise (default) it must be either passed completely in registers or completely on the stack.

Definition at line 376 of file CompilerBase.hpp.

◆ result_ref_alias()

CompilerBase< Adaptor, Derived, Config >::ValueRef tpde::CompilerBase< Adaptor, Derived, Config >::result_ref_alias	(	IRValueRef	dst,
		ValueRef &&	src )

Make dst an alias for src, which must be a non-constant value with an identical part configuration.

src must be in its last use (is_owned()), and the assignment will be repurposed for dst, keeping all assigned registers and stack slots.

Definition at line 405 of file CompilerBase.hpp.

◆ result_ref_single()

std::pair< typename CompilerBase< Adaptor, Derived, Config >::ValueRef, typename CompilerBase< Adaptor, Derived, Config >::ValuePartRef > tpde::CompilerBase< Adaptor, Derived, Config >::result_ref_single ( IRValueRef value )

Get a defining reference to a single-part value and provide direct access to the only part.

Similar to val_ref_single().

Definition at line 399 of file CompilerBase.hpp.

◆ result_ref_stack_slot()

CompilerBase< Adaptor, Derived, Config >::ValueRef tpde::CompilerBase< Adaptor, Derived, Config >::result_ref_stack_slot	(	IRValueRef	value,
		AssignmentPartRef	base,
		i32	off )

Initialize value as a pointer into a stack variable (i.e., a value allocated from cur_static_allocas() or similar) with an offset.

The result value will be a stack variable itself.

Definition at line 411 of file CompilerBase.hpp.

◆ spill_before_branch()

CompilerBase< Adaptor, Derived, Config >::RegisterFile::RegBitSet tpde::CompilerBase< Adaptor, Derived, Config >::spill_before_branch ( bool force_spill = false )

Spill values that need to be spilled for later blocks.

Returns the set of registers that will be free'd at the end of the block; pass this to release_spilled_regs().

Definition at line 512 of file CompilerBase.hpp.

◆ val_ref_single()

std::pair< typename CompilerBase< Adaptor, Derived, Config >::ValueRef, typename CompilerBase< Adaptor, Derived, Config >::ValuePartRef > tpde::CompilerBase< Adaptor, Derived, Config >::val_ref_single ( IRValueRef value )

Get a using reference to a single-part value and provide direct access to the only part.

This is a convenience function; note that the ValueRef must outlive the ValuePartRef (i.e. auto p = val_ref().part(0); won't work, as the value will possibly be deallocated when the ValueRef is destroyed).

Definition at line 392 of file CompilerBase.hpp.

Member Data Documentation

◆ frame_used

bool tpde::CompilerBase< Adaptor, Derived, Config >::frame_used

Whether the stack frame is used.

If the stack frame is never used, the frame setup can in some cases be omitted entirely.

Definition at line 146 of file CompilerBase.hpp.

◆ generated_call

bool tpde::CompilerBase< Adaptor, Derived, Config >::generated_call

Whether the function actually includes a call.

There are cases, where it is not clear from the beginning whether a function has function calls. If a function has no calls, this will allow using the red zone guaranteed by some ABIs.

Definition at line 143 of file CompilerBase.hpp.

◆ has_dynamic_alloca

bool tpde::CompilerBase< Adaptor, Derived, Config >::has_dynamic_alloca

Whether the stack frame might have dynamic alloca.

Dynamic allocas may require a different and less efficient frame setup. As static allocas can be converted into dynamic allocas, this is only valid after static allocas were processed.

Definition at line 135 of file CompilerBase.hpp.

◆ is_leaf_function

bool tpde::CompilerBase< Adaptor, Derived, Config >::is_leaf_function

Whether the function is guaranteed to be a leaf function.

Throughout the entire function, the compiler may assume the absence of function calls.

Definition at line 138 of file CompilerBase.hpp.

The documentation for this struct was generated from the following files:

tpde/include/tpde/ScratchReg.hpp
tpde/include/tpde/CompilerBase.hpp

Public Member Functions

Public Attributes