From ed038678ef23a4b5ca18ed2c803fe3f7289ef037 Mon Sep 17 00:00:00 2001 From: "Wesley W. Terpstra" Date: Thu, 22 Sep 2016 11:33:40 -0700 Subject: [PATCH] tilelink2 Fuzzer: work around for firrtl/verilator performance issue Big Vec()s cause very slow compilation. --- src/main/scala/uncore/tilelink2/Fuzzer.scala | 21 +++++++++---------- src/main/scala/uncore/tilelink2/package.scala | 6 ++++++ 2 files changed, 16 insertions(+), 11 deletions(-) diff --git a/src/main/scala/uncore/tilelink2/Fuzzer.scala b/src/main/scala/uncore/tilelink2/Fuzzer.scala index 6d46bd6b..aa7e0d2a 100644 --- a/src/main/scala/uncore/tilelink2/Fuzzer.scala +++ b/src/main/scala/uncore/tilelink2/Fuzzer.scala @@ -14,23 +14,22 @@ class IDMapGenerator(numIds: Int) extends Module { } // True indicates that the id is available - val bitmap = RegInit(Vec.fill(numIds){Bool(true)}) + val bitmap = RegInit(UInt((BigInt(1) << numIds) - 1, width = numIds)) io.free.ready := Bool(true) - assert(!io.free.valid || !bitmap(io.free.bits)) // No double freeing + assert (!io.free.valid || !bitmap(io.free.bits)) // No double freeing - val mask = bitmap.scanLeft(Bool(false))(_||_).init - val select = mask zip bitmap map { case(m,b) => !m && b } + val select = ~(highOR(bitmap) << 1) & bitmap io.alloc.bits := OHToUInt(select) - io.alloc.valid := bitmap.reduce(_||_) + io.alloc.valid := bitmap.orR() - when (io.alloc.fire()) { - bitmap(io.alloc.bits) := Bool(false) - } + val clr = Wire(init = UInt(0, width = numIds)) + when (io.alloc.fire()) { clr := UIntToOH(io.alloc.bits) } - when (io.free.fire()) { - bitmap(io.free.bits) := Bool(true) - } + val set = Wire(init = UInt(0, width = numIds)) + when (io.free.fire()) { set := UIntToOH(io.free.bits) } + + bitmap := (bitmap & ~clr) | set } object LFSR64 diff --git a/src/main/scala/uncore/tilelink2/package.scala b/src/main/scala/uncore/tilelink2/package.scala index 050a4b6d..c1cfeb45 100644 --- a/src/main/scala/uncore/tilelink2/package.scala +++ b/src/main/scala/uncore/tilelink2/package.scala @@ -10,6 +10,12 @@ package object tilelink2 def OH1ToUInt(x: UInt) = OHToUInt((x << 1 | UInt(1)) ^ x) def UIntToOH1(x: UInt, width: Int) = ~(SInt(-1, width=width).asUInt << x)(width-1, 0) def trailingZeros(x: Int) = if (x > 0) Some(log2Ceil(x & -x)) else None + def highOR(x: UInt) = { + val w = x.getWidth + def helper(s: Int, x: UInt): UInt = + if (s >= w) x else helper(s+s, x | x << s) + helper(1, x) + } def sourceLine(sourceInfo: SourceInfo, prefix: String = " (", suffix: String = ")") = sourceInfo match { case SourceLine(filename, line, col) => s"$prefix$filename:$line:$col$suffix"