From 11b0272d917c25706cc837382abc9b2c511321d1 Mon Sep 17 00:00:00 2001
From: "Wesley W. Terpstra" <wesley@sifive.com>
Date: Fri, 2 Sep 2016 19:55:08 -0700
Subject: [PATCH] tilelink2: create optimized hasData method on edges
 (statically evaluates if known)

---
 uncore/src/main/scala/tilelink2/Bundles.scala | 17 ++++++++
 uncore/src/main/scala/tilelink2/Edges.scala   | 41 ++++++++++++++++++-
 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/uncore/src/main/scala/tilelink2/Bundles.scala b/uncore/src/main/scala/tilelink2/Bundles.scala
index 88b742d7..0c0a95e4 100644
--- a/uncore/src/main/scala/tilelink2/Bundles.scala
+++ b/uncore/src/main/scala/tilelink2/Bundles.scala
@@ -106,12 +106,24 @@ object Bogus
   def apply() = new Bogus
 }
 
+object ChannelType {
+  sealed trait T
+  case object A extends T
+  case object B extends T
+  case object C extends T
+  case object D extends T
+  case object E extends T
+  val cases = Seq(A, B, C, D, E)
+}
+
 trait HasTLOpcode
 {
   // The data field in this message has value
   def hasData(x: Bogus = Bogus()): Bool
   // This message requires a response
   def hasFollowUp(x: Bogus = Bogus()): Bool
+  // What channel type is this?
+  def channelType(x: Bogus = Bogus()): ChannelType.T
   // The size field of the opcode
   def size(x: Bogus = Bogus()): UInt
 }
@@ -142,6 +154,7 @@ class TLBundleA(params: TLBundleParameters)
 //    opcode === TLMessages.ArithmeticData ||
 //    opcode === TLMessages.LogicalData
   def hasFollowUp(x: Bogus = Bogus()) = Bool(true)
+  def channelType(x: Bogus = Bogus()) = ChannelType.A
   def size(x: Bogus = Bogus()) = size
   def data(x: Bogus = Bogus()) = data
   def mask(x: Bogus = Bogus()) = mask
@@ -163,6 +176,7 @@ class TLBundleB(params: TLBundleParameters)
 
   def hasData(x: Bogus = Bogus()) = !opcode(2)
   def hasFollowUp(x: Bogus = Bogus()) = Bool(true)
+  def channelType(x: Bogus = Bogus()) = ChannelType.B
   def size(x: Bogus = Bogus()) = size
   def data(x: Bogus = Bogus()) = data
   def mask(x: Bogus = Bogus()) = mask
@@ -189,6 +203,7 @@ class TLBundleC(params: TLBundleParameters)
   def hasFollowUp(x: Bogus = Bogus()) = opcode(2) && opcode(1)
 //    opcode === TLMessages.Release ||
 //    opcode === TLMessages.ReleaseData
+  def channelType(x: Bogus = Bogus()) = ChannelType.C
   def size(x: Bogus = Bogus()) = size
   def data(x: Bogus = Bogus()) = data
   def mask(x: Bogus = Bogus()) = SInt(-1, width = params.dataBits/8).asUInt
@@ -214,6 +229,7 @@ class TLBundleD(params: TLBundleParameters)
   def hasFollowUp(x: Bogus = Bogus()) = opcode(2) && !opcode(1)
 //    opcode === TLMessages.Grant     ||
 //    opcode === TLMessages.GrantData
+  def channelType(x: Bogus = Bogus()) = ChannelType.D
   def size(x: Bogus = Bogus()) = size
   def data(x: Bogus = Bogus()) = data
   def mask(x: Bogus = Bogus()) = SInt(-1, width = params.dataBits/8).asUInt
@@ -227,6 +243,7 @@ class TLBundleE(params: TLBundleParameters)
 
   def hasData(x: Bogus = Bogus()) = Bool(false)
   def hasFollowUp(x: Bogus = Bogus()) = Bool(false)
+  def channelType(x: Bogus = Bogus()) = ChannelType.E
   def size(x: Bogus = Bogus()) = UInt(log2Up(params.dataBits/8))
 }
 
diff --git a/uncore/src/main/scala/tilelink2/Edges.scala b/uncore/src/main/scala/tilelink2/Edges.scala
index cd1a2449..0d178560 100644
--- a/uncore/src/main/scala/tilelink2/Edges.scala
+++ b/uncore/src/main/scala/tilelink2/Edges.scala
@@ -39,8 +39,47 @@ class TLEdge(
     Cat(helper(lgBytes).map(_._1).reverse)
   }
 
+  def staticHasData(bundle: HasTLOpcode): Option[Boolean] = {
+    bundle.channelType() match {
+      case ChannelType.A => {
+        // Do there exist A messages with Data?
+        val aDataYes = manager.anySupportArithmetic || manager.anySupportLogical || manager.anySupportPutFull || manager.anySupportPutPartial
+        // Do there exist A messages without Data?
+        val aDataNo  = manager.anySupportAcquire || manager.anySupportGet || manager.anySupportHint
+        // Statically optimize the case where hasData is a constant
+        if (!aDataYes) Some(false) else if (!aDataNo) Some(true) else None
+      }
+      case ChannelType.B => {
+        // Do there exist B messages with Data?
+        val bDataYes = client.anySupportArithmetic || client.anySupportLogical || client.anySupportPutFull || client.anySupportPutPartial
+        // Do there exist B messages without Data?
+        val bDataNo  = client.anySupportProbe || client.anySupportGet || client.anySupportHint
+        // Statically optimize the case where hasData is a constant
+        if (!bDataYes) Some(false) else if (!bDataNo) Some(true) else None
+      }
+      case ChannelType.C => {
+        // Do there eixst C messages with Data?
+        val cDataYes = client.anySupportGet || client.anySupportArithmetic || client.anySupportLogical || client.anySupportProbe
+        // Do there exist C messages without Data?
+        val cDataNo  = client.anySupportPutFull || client.anySupportPutPartial || client.anySupportHint || client.anySupportProbe
+        if (!cDataYes) Some(false) else if (!cDataNo) Some(true) else None
+      }
+      case ChannelType.D => {
+        // Do there eixst D messages with Data?
+        val dDataYes = manager.anySupportGet || manager.anySupportArithmetic || manager.anySupportLogical || manager.anySupportAcquire
+        // Do there exist D messages without Data?
+        val dDataNo  = manager.anySupportPutFull || manager.anySupportPutPartial || manager.anySupportHint || manager.anySupportAcquire
+        if (!dDataYes) Some(false) else if (!dDataNo) Some(true) else None
+      }
+      case ChannelType.E => Some(false)
+    }
+  }
+
+  def hasData(bundle: HasTLOpcode): Bool =
+    staticHasData(bundle).map(Bool(_)).getOrElse(bundle.hasData())
+
   def numBeats(bundle: HasTLOpcode) = {
-    val hasData = bundle.hasData()
+    val hasData = this.hasData(bundle)
     val size = bundle.size()
     val cutoff = log2Ceil(manager.beatBytes)
     val small = size <= UInt(cutoff)