From 747925f8fd8c31cca867eccbe95e44c12a174216 Mon Sep 17 00:00:00 2001
From: Karol Stasiak <karol.m.stasiak@gmail.com>
Date: Mon, 26 Feb 2018 17:49:55 +0100
Subject: [PATCH] Added new -O1 optimization preset

---
 CHANGELOG.md                                  |  2 ++
 src/main/scala/millfork/Main.scala            | 29 +++++++++++--------
 .../scala/millfork/OptimizationPresets.scala  | 17 +++++++++++
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 28c59c9f..9939e508 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 * **Breaking change!** Renamed `inline` to `macro`.
 
+* Added new `-O1` optimization preset; old `-O1` became `-O2`, old `-O2` became `-O3` and so on.
+
 * Added support for parameters for macros written in Millfork.
 
 * Enabled calling macros with index expression parameters.
diff --git a/src/main/scala/millfork/Main.scala b/src/main/scala/millfork/Main.scala
index 778a04bd..f4aea1a6 100644
--- a/src/main/scala/millfork/Main.scala
+++ b/src/main/scala/millfork/Main.scala
@@ -86,14 +86,19 @@ object Main {
 
     val env = new Environment(None, "")
     env.collectDeclarations(program, options)
-    val extras = List(
-      if (options.flag(CompilationFlag.EmitIllegals)) UndocumentedOptimizations.All else Nil,
-      if (options.flag(CompilationFlag.EmitCmosOpcodes)) CmosOptimizations.All else LaterOptimizations.Nmos,
-      if (options.flag(CompilationFlag.DangerousOptimizations)) DangerousOptimizations.All else Nil,
-    ).flatten
-    val goodCycle = List.fill(optLevel - 1)(OptimizationPresets.Good).flatten
-    val assemblyOptimizations = if (optLevel <= 0) Nil else if (optLevel >= 9) List(SuperOptimizer) else {
-      goodCycle ++ OptimizationPresets.AssOpt ++ extras ++ goodCycle
+
+    val assemblyOptimizations = optLevel match {
+      case 0 => Nil
+      case 1 => OptimizationPresets.QuickPreset
+      case i if i >= 9 => List(SuperOptimizer)
+      case _ =>
+        val extras = List(
+          if (options.flag(CompilationFlag.EmitIllegals)) UndocumentedOptimizations.All else Nil,
+          if (options.flag(CompilationFlag.EmitCmosOpcodes)) CmosOptimizations.All else LaterOptimizations.Nmos,
+          if (options.flag(CompilationFlag.DangerousOptimizations)) DangerousOptimizations.All else Nil,
+        ).flatten
+        val goodCycle = List.fill(optLevel - 2)(OptimizationPresets.Good).flatten
+        goodCycle ++ OptimizationPresets.AssOpt ++ extras ++ goodCycle
     }
 
     // compile
@@ -188,7 +193,7 @@ object Main {
     }.description("Whether should emit CMOS opcodes.")
     boolean("-fillegals", "-fno-illegals").action { (c, v) =>
       c.changeFlag(CompilationFlag.EmitIllegals, v)
-    }.description("Whether should emit illegal (undocumented) NMOS opcodes.")
+    }.description("Whether should emit illegal (undocumented) NMOS opcodes. Required -O2 or higher to have an effect.")
     boolean("-fjmp-fix", "-fno-jmp-fix").action { (c, v) =>
       c.changeFlag(CompilationFlag.PreventJmpIndirectBug, v)
     }.description("Whether should prevent indirect JMP bug on page boundary.")
@@ -230,18 +235,18 @@ object Main {
       c.changeFlag(CompilationFlag.OptimizeForSize, true)
       c.changeFlag(CompilationFlag.OptimizeForSpeed, false)
       c.changeFlag(CompilationFlag.OptimizeForSonicSpeed, false)
-    }.description("Optimize for size at cost of lower speed (experimental).")
+    }.description("Prefer smaller code even if it is slightly slower (experimental).")
     flag("-Of", "--fast").action { c =>
       c.changeFlag(CompilationFlag.OptimizeForSize, false)
       c.changeFlag(CompilationFlag.OptimizeForSpeed, true)
       c.changeFlag(CompilationFlag.OptimizeForSonicSpeed, false)
-    }.description("Optimize for speed at cost of bigger size (experimental).")
+    }.description("Prefer faster code even if it is slightly bigger (experimental).")
     flag("-Ob", "--blast-processing").action { c =>
       c.changeFlag(CompilationFlag.OptimizeForSize, false)
       c.changeFlag(CompilationFlag.OptimizeForSpeed, true)
       c.changeFlag(CompilationFlag.OptimizeForSonicSpeed, true)
       c.changeFlag(CompilationFlag.InlineFunctions, true)
-    }.description("Optimize for speed at cost of much bigger size (experimental). Implies --inline.")
+    }.description("Prefer faster code even if it is much bigger (experimental). Implies --inline.")
     flag("--detailed-flow").action { c =>
       c.changeFlag(CompilationFlag.DetailedFlowAnalysis, true)
     }.description("Use detailed flow analysis (experimental).")
diff --git a/src/main/scala/millfork/OptimizationPresets.scala b/src/main/scala/millfork/OptimizationPresets.scala
index 4e3a8636..f7a54a48 100644
--- a/src/main/scala/millfork/OptimizationPresets.scala
+++ b/src/main/scala/millfork/OptimizationPresets.scala
@@ -179,4 +179,21 @@ object OptimizationPresets {
     AlwaysGoodOptimizations.UnusedLabelRemoval,
     VariableToRegisterOptimization,
   )
+
+  val QuickPreset: List[AssemblyOptimization] = List[AssemblyOptimization](
+    AlwaysGoodOptimizations.Adc0Optimization,
+    AlwaysGoodOptimizations.BranchInPlaceRemoval,
+    AlwaysGoodOptimizations.CommonBranchBodyOptimization,
+    AlwaysGoodOptimizations.CommonExpressionInConditional,
+    AlwaysGoodOptimizations.CommonIndexSubexpressionElimination,
+    AlwaysGoodOptimizations.IndexSequenceOptimization,
+    AlwaysGoodOptimizations.PoinlessStoreBeforeStore,
+    AlwaysGoodOptimizations.PointlessLoadAfterLoadOrStore,
+    AlwaysGoodOptimizations.PointlessLoadBeforeTransfer,
+    AlwaysGoodOptimizations.PointlessOperationFromFlow,
+    AlwaysGoodOptimizations.ReverseFlowAnalysis,
+    AlwaysGoodOptimizations.SimplifiableCondition,
+    VariableToRegisterOptimization,
+    LaterOptimizations.DoubleLoadToTheSameRegister
+  )
 }