From d9a0b40286b2424a6a7f1bdd9f7a5232a6e5e513 Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Mon, 30 May 2022 14:19:42 +0200
Subject: [PATCH 1/2] builder: move some code to transform package

The transform package is the more appropriate location for package-level
optimizations, to match `transform.Optimize` for whole-program
optimizations.
This is just a refactor, to make later changes easier to read.
---
 builder/build.go       | 22 +---------------------
 transform/optimizer.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/builder/build.go b/builder/build.go
index cf9f577760..d0e92d7c96 100644
--- a/builder/build.go
+++ b/builder/build.go
@@ -439,27 +439,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 					return errors.New("verification error after interpreting " + pkgInit.Name())
 				}
 
-				// Run function passes for each function in the module.
-				// These passes are intended to be run on each function right
-				// after they're created to reduce IR size (and maybe also for
-				// cache locality to improve performance), but for now they're
-				// run here for each function in turn. Maybe this can be
-				// improved in the future.
-				builder := llvm.NewPassManagerBuilder()
-				defer builder.Dispose()
-				builder.SetOptLevel(optLevel)
-				builder.SetSizeLevel(sizeLevel)
-				funcPasses := llvm.NewFunctionPassManagerForModule(mod)
-				defer funcPasses.Dispose()
-				builder.PopulateFunc(funcPasses)
-				funcPasses.InitializeFunc()
-				for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
-					if fn.IsDeclaration() {
-						continue
-					}
-					funcPasses.RunFunc(fn)
-				}
-				funcPasses.FinalizeFunc()
+				transform.OptimizePackage(mod, config)
 
 				// Serialize the LLVM module as a bitcode file.
 				// Write to a temporary path that is renamed to the destination
diff --git a/transform/optimizer.go b/transform/optimizer.go
index 8e2ef7a83a..66ad43f4ba 100644
--- a/transform/optimizer.go
+++ b/transform/optimizer.go
@@ -11,6 +11,34 @@ import (
 	"tinygo.org/x/go-llvm"
 )
 
+// OptimizePackage runs optimization passes over the LLVM module for the given
+// Go package.
+func OptimizePackage(mod llvm.Module, config *compileopts.Config) {
+	optLevel, sizeLevel, _ := config.OptLevels()
+
+	// Run function passes for each function in the module.
+	// These passes are intended to be run on each function right
+	// after they're created to reduce IR size (and maybe also for
+	// cache locality to improve performance), but for now they're
+	// run here for each function in turn. Maybe this can be
+	// improved in the future.
+	builder := llvm.NewPassManagerBuilder()
+	defer builder.Dispose()
+	builder.SetOptLevel(optLevel)
+	builder.SetSizeLevel(sizeLevel)
+	funcPasses := llvm.NewFunctionPassManagerForModule(mod)
+	defer funcPasses.Dispose()
+	builder.PopulateFunc(funcPasses)
+	funcPasses.InitializeFunc()
+	for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+		if fn.IsDeclaration() {
+			continue
+		}
+		funcPasses.RunFunc(fn)
+	}
+	funcPasses.FinalizeFunc()
+}
+
 // Optimize runs a number of optimization and transformation passes over the
 // given module. Some passes are specific to TinyGo, others are generic LLVM
 // passes. You can set a preferred performance (0-3) and size (0-2) level and

From f1827ede051b181817cef5dedc7c605696e94dbe Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Mon, 30 May 2022 14:55:14 +0200
Subject: [PATCH 2/2] transform: run OptimizeMaps during package optimizations

This shrinks transform.Optimize() a little bit, working towards the goal
of https://github.com/tinygo-org/tinygo/issues/2870. I ran the smoke
tests and there is no practical downside: one test got smaller (??) and
one had a different .hex hash, but other than that there was no
difference.

This should also make TinyGo a liiitle bit faster but it's probably not
even measurable.
---
 transform/optimizer.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/transform/optimizer.go b/transform/optimizer.go
index 66ad43f4ba..e688a53947 100644
--- a/transform/optimizer.go
+++ b/transform/optimizer.go
@@ -37,6 +37,11 @@ func OptimizePackage(mod llvm.Module, config *compileopts.Config) {
 		funcPasses.RunFunc(fn)
 	}
 	funcPasses.FinalizeFunc()
+
+	// Run TinyGo-specific optimization passes.
+	if optLevel > 0 {
+		OptimizeMaps(mod)
+	}
 }
 
 // Optimize runs a number of optimization and transformation passes over the
@@ -92,7 +97,6 @@ func Optimize(mod llvm.Module, config *compileopts.Config, optLevel, sizeLevel i
 		goPasses.Run(mod)
 
 		// Run TinyGo-specific optimization passes.
-		OptimizeMaps(mod)
 		OptimizeStringToBytes(mod)
 		OptimizeReflectImplements(mod)
 		OptimizeAllocs(mod, nil, nil)