tinygo/transform/transform.go

// Package transform contains transformation passes for the TinyGo compiler.
// These transformation passes may be optimization passes or lowering passes.
//
// Optimization passes transform the IR in such a way that they increase the
// performance of the generated code and/or help the LLVM optimizer better do
// its job by simplifying the IR. This usually means that certain
// TinyGo-specific runtime calls are removed or replaced with something simpler
// if that is a valid operation.
//
// Lowering passes are usually required to run. One example is the interface
// lowering pass, which replaces stub runtime calls to get an interface method
// with the method implementation (either a direct call or a thunk).
package transform

import (
	"github.com/tinygo-org/tinygo/compileopts"
	"tinygo.org/x/go-llvm"
)

// AddStandardAttributes is a helper function to add standard function
// attributes to a function. For example, it adds optsize when requested from
// the -opt= compiler flag.
func AddStandardAttributes(fn llvm.Value, config *compileopts.Config) {
	ctx := fn.Type().Context()
	_, sizeLevel, _ := config.OptLevels()
	if sizeLevel >= 1 {
		fn.AddFunctionAttr(ctx.CreateEnumAttribute(llvm.AttributeKindID("optsize"), 0))
	}
	if sizeLevel >= 2 {
		fn.AddFunctionAttr(ctx.CreateEnumAttribute(llvm.AttributeKindID("minsize"), 0))
	}
	if config.CPU() != "" {
		fn.AddFunctionAttr(ctx.CreateStringAttribute("target-cpu", config.CPU()))
	}
	if config.Features() != "" {
		fn.AddFunctionAttr(ctx.CreateStringAttribute("target-features", config.Features()))
	}
}