| // Copyright 2024 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package common |
| |
| import chisel3._ |
| import chisel3.util._ |
| |
| class Fp32 extends Bundle { |
| val mantissa = UInt(23.W) |
| val exponent = UInt(8.W) |
| val sign = Bool() |
| |
| def asWord(): UInt = { |
| Cat(sign, exponent, mantissa) |
| } |
| |
| def isZero(): Bool = { |
| (exponent === 0.U) && (mantissa === 0.U) |
| } |
| |
| def isInf(): Bool = { |
| (exponent === "b11111111".U) && (mantissa === 0.U) |
| } |
| |
| def isNan(): Bool = { |
| (exponent === "b11111111".U) && (mantissa =/= 0.U) |
| } |
| |
| // The mantissa is the fractional component of significand. |
| // There is a leading 1, except for subnormal numbers. |
| def significand(): UInt = { |
| Cat(exponent.orR, mantissa) |
| } |
| |
| def negate(): Fp32 = { |
| val negated = Wire(new Fp32) |
| negated.sign := ~sign |
| negated.exponent := exponent |
| negated.mantissa := mantissa |
| negated |
| } |
| } |
| |
| object Fp32 { |
| def apply(sign: Bool, exponent: UInt, mantissa: UInt): Fp32 = { |
| assert(exponent.getWidth == 8) |
| assert(mantissa.getWidth == 23) |
| val fp = Wire(new Fp32) |
| fp.mantissa := mantissa |
| fp.exponent := exponent |
| fp.sign := sign |
| fp |
| } |
| |
| def fromWord(word: UInt): Fp32 = { |
| assert(word.getWidth == 32) |
| val fp = Wire(new Fp32) |
| fp.mantissa := word(22, 0) |
| fp.exponent := word(30, 23) |
| fp.sign := word(31) |
| fp |
| } |
| |
| def Zero(sign: Bool): Fp32 = { |
| val fp = Wire(new Fp32) |
| fp.mantissa := 0.U |
| fp.exponent := 0.U |
| fp.sign := sign |
| fp |
| } |
| |
| def Inf(sign: Bool): Fp32 = { |
| val fp = Wire(new Fp32) |
| fp.mantissa := 0.U |
| fp.exponent := "b11111111".U |
| fp.sign := sign |
| fp |
| } |
| |
| def NaN(): Fp32 = { |
| val fp = Wire(new Fp32) |
| fp.mantissa := (1 << 22).U // Cannonical NaN per RV32F spec |
| fp.exponent := "b11111111".U |
| fp.sign := 0.U |
| fp |
| } |
| } |