Module isa

Instruction Set Architectures.

The isa module provides a TargetIsa trait which provides the behavior specialization needed by the ISA-independent code generator. The sub-modules of this module provide definitions for the instruction sets that Cranelift can target. Each sub-module has it’s own implementation of TargetIsa.

Constructing a TargetIsa instance

The target ISA is built from the following information:

• The name of the target ISA as a string. Cranelift is a cross-compiler, so the ISA to target can be selected dynamically. Individual ISAs can be left out when Cranelift is compiled, so a string is used to identify the proper sub-module.
• Values for settings that apply to all ISAs. This is represented by a settings::Flags instance.
• Values for ISA-specific settings.

The isa::lookup() function is the main entry point which returns an isa::Builder appropriate for the requested ISA:

use cranelift_codegen::isa;
use cranelift_codegen::settings::{self, Configurable};
use std::str::FromStr;
use target_lexicon::Triple;

let shared_builder = settings::builder();
let shared_flags = settings::Flags::new(shared_builder);

match isa::lookup(triple!("x86_64")) {
    Err(_) => {
        // The x86_64 target ISA is not available.
    }
    Ok(mut isa_builder) => {
        isa_builder.set("use_popcnt", "on");
        let isa = isa_builder.finish(shared_flags);
    }
}

The configured target ISA trait object is a Box<TargetIsa> which can be used for multiple concurrent function compilations.

Modules

aarch64arm64

ARM 64-bit Instruction Set Architecture.

riscv64riscv64

risc-v 64-bit Instruction Set Architecture.

unwind

Represents information relating to function unwinding.

x64x86

X86_64-bit Instruction Set Architecture.

Structs

FunctionAlignment

Function alignment specifications as required by an ISA, returned by TargetIsa::function_alignment.

IsaBuilder

Builder for a TargetIsa. Modify the ISA-specific settings before creating the TargetIsa trait object with finish.

TargetFrontendConfig

This struct provides information that a frontend may need to know about a target to produce Cranelift IR for the target.

Enums

CallConv

Calling convention identifiers.

LookupError

Describes reason for target lookup failure

Constants

ALL_ARCHITECTURES

The string names of all the supported, but possibly not enabled, architectures. The elements of this slice are suitable to be passed to the lookup_by_name function to obtain the default configuration for that architecture.

Traits

TargetIsa

Methods that are specialized to a target ISA.

Functions

lookup

Look for an ISA for the given triple. Return a builder that can create a corresponding TargetIsa.

lookup_by_name

Look for a supported ISA with the given name. Return a builder that can create a corresponding TargetIsa.

Type Aliases

Builder

Type alias of IsaBuilder used for building Cranelift’s ISAs.

Legalize

After determining that an instruction doesn’t have an encoding, how should we proceed to legalize it?

OwnedTargetIsa

The type of a polymorphic TargetISA object which is ’static.