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Extend AMOALU to support RV32

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This commit is contained in:
Andrew Waterman 2016-03-10 17:19:42 -08:00
parent c28d115b30
commit 2eafc4c8f3
1 changed files with 18 additions and 10 deletions
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14
uncore/src/main/scala/amoalu.scala
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@ -53,7 +53,7 @@ class LoadGen(typ: UInt, addr: UInt, dat: UInt, zero: Bool, maxSize: Int) {
class AMOALU(rhsIsAligned: Boolean = false)(implicit p: Parameters) extends CacheModule()(p) {
val operandBits = p(AmoAluOperandBits)
require(operandBits == 64)
require(operandBits == 32 || operandBits == 64)
val io = new Bundle {
val addr = Bits(INPUT, blockOffBits)
val cmd = Bits(INPUT, M_SZ)
@ -74,16 +74,24 @@ class AMOALU(rhsIsAligned: Boolean = false)(implicit p: Parameters) extends Cach
val word = io.typ === MT_W || io.typ === MT_WU || // Logic minimization:
io.typ === MT_B || io.typ === MT_BU
val adder_out =
if (operandBits == 32) io.lhs + rhs
else {
val mask = ~UInt(0,64) ^ (io.addr(2) << 31)
val adder_out = (io.lhs & mask).toUInt + (rhs & mask)
(io.lhs & mask).toUInt + (rhs & mask)
}
val less =
if (operandBits == 32) Mux(io.lhs(31) === rhs(31), io.lhs < rhs, Mux(sgned, io.lhs(31), io.rhs(31)))
else {
val cmp_lhs = Mux(word && !io.addr(2), io.lhs(31), io.lhs(63))
val cmp_rhs = Mux(word && !io.addr(2), rhs(31), rhs(63))
val lt_lo = io.lhs(31,0) < rhs(31,0)
val lt_hi = io.lhs(63,32) < rhs(63,32)
val eq_hi = io.lhs(63,32) === rhs(63,32)
val lt = Mux(word, Mux(io.addr(2), lt_hi, lt_lo), lt_hi || eq_hi && lt_lo)
val less = Mux(cmp_lhs === cmp_rhs, lt, Mux(sgned, cmp_lhs, cmp_rhs))
Mux(cmp_lhs === cmp_rhs, lt, Mux(sgned, cmp_lhs, cmp_rhs))
}
val out = Mux(io.cmd === M_XA_ADD, adder_out,
Mux(io.cmd === M_XA_AND, io.lhs & rhs,