From 27581f8d28d1ac2e1d2a86ff2b45dfda63c9b594 Mon Sep 17 00:00:00 2001
From: Kevin Kim <kevindkim723@gmail.com>
Date: Sat, 18 Feb 2023 20:57:07 -0800
Subject: [PATCH] alu and controllers handle andn, orn, xnor
---
src/ieu/alu.sv | 4 ++--
src/ieu/bmu/bmuctrl.sv | 3 +++
src/ieu/bmu/zbb.sv | 2 +-
src/ieu/controller.sv | 14 +++++++++++++-
4 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/src/ieu/alu.sv b/src/ieu/alu.sv
index 164a2810a..97400f447 100644
--- a/src/ieu/alu.sv
+++ b/src/ieu/alu.sv
@@ -113,8 +113,8 @@ module alu #(parameter WIDTH=32) (
3'b001: FullResult = Shift; // sll, sra, or srl
3'b010: FullResult = SLT; // slt
3'b011: FullResult = SLTU; // sltu
- 3'b100: FullResult = A ^ CondMaskB; // xor, binv
- 3'b110: FullResult = A | CondMaskB; // or, bset
+ 3'b100: FullResult = A ^ CondInvB; // xor, xnor, binv
+ 3'b110: FullResult = A | CondInvB; // or, orn, bset
3'b111: FullResult = A & CondInvB; // and, bclr
3'b101: FullResult = {{(WIDTH-1){1'b0}},{|(A & CondMaskB)}};// bext
endcase
diff --git a/src/ieu/bmu/bmuctrl.sv b/src/ieu/bmu/bmuctrl.sv
index ef021db0e..abaf36558 100644
--- a/src/ieu/bmu/bmuctrl.sv
+++ b/src/ieu/bmu/bmuctrl.sv
@@ -129,6 +129,9 @@ module bmuctrl(
BMUControlsD = `BMUCTRLW'b000_0100_100; // zexth (rv32)
else
BMUControlsD = `BMUCTRLW'b000_0000_000; // illegal instruction
+ 17'b0110011_0100000_111: BMUControlsD = `BMUCTRLW'b111_0100_111; // andn
+ 17'b0110011_0100000_110: BMUControlsD = `BMUCTRLW'b110_0100_111; // orn
+ 17'b0110011_0100000_100: BMUControlsD = `BMUCTRLW'b100_0100_111; // xnor
default: BMUControlsD = {Funct3D, {7'b0}}; // not B instruction or shift
endcase
diff --git a/src/ieu/bmu/zbb.sv b/src/ieu/bmu/zbb.sv
index d5198d484..bacbef817 100644
--- a/src/ieu/bmu/zbb.sv
+++ b/src/ieu/bmu/zbb.sv
@@ -56,7 +56,7 @@ module zbb #(parameter WIDTH=32) (
//can replace with structural mux by looking at bit 4 in rs2 field
always_comb begin
case (ZBBSelect)
- 3'b111: ZBBResult = ALUResult; // rotate
+ 3'b111: ZBBResult = ALUResult; // rotates, andn, xnor, orn
3'b000: ZBBResult = CntResult; // count
3'b100: ZBBResult = ExtResult; // sign/zero extend
/*15'b0010100_101_00111: ZBBResult = OrcBResult;
diff --git a/src/ieu/controller.sv b/src/ieu/controller.sv
index 70d5f5987..74d0e4f1e 100644
--- a/src/ieu/controller.sv
+++ b/src/ieu/controller.sv
@@ -107,6 +107,7 @@ module controller(
logic SubArithD; // TRUE for R-type subtracts and sra, slt, sltu
logic subD, sraD, sltD, sltuD; // Indicates if is one of these instructions
logic bclrD, bextD; // Indicates if is one of these instructions
+ logic andnD, ornD, xnorD; // Indicates if is one of these instructions
logic BranchTakenE; // Branch is taken
logic eqE, ltE; // Comparator outputs
logic unused;
@@ -210,11 +211,22 @@ module controller(
assign bclrD = 1'b0;
assign bextD = 1'b0;
end
+
+ if (`ZBB_SUPPORTED) begin
+ assign andnD = (ALUSelectD == 3'b111 & BSelectD[2]);
+ assign ornD = (ALUSelectD == 3'b110 & BSelectD[2]);
+ assign xnorD = (ALUSelectD == 3'b100 & BSelectD[2]);
+ end else begin
+ assign andnD = 0;
+ assign ornD = 0;
+ assign xnorD = 0;
+ end
+
// ALU Decoding is lazy, only using func7[5] to distinguish add/sub and srl/sra
assign sltuD = (Funct3D == 3'b011);
assign subD = (Funct3D == 3'b000 & Funct7D[5] & OpD[5]); // OpD[5] needed to distinguish sub from addi
assign sraD = (Funct3D == 3'b101 & Funct7D[5]);
- assign SubArithD = ALUOpD & (subD | sraD | sltD | sltuD | (`ZBS_SUPPORTED & (bextD | bclrD))); // TRUE for R-type subtracts and sra, slt, sltu
+ assign SubArithD = ALUOpD & (subD | sraD | sltD | sltuD | (`ZBS_SUPPORTED & (bextD | bclrD)) | (`ZBB_SUPPORTED & (andnD | ornD | xnorD))); // TRUE for R-type subtracts and sra, slt, sltu, and any B instruction that requires inverted operand
assign ALUControlD = {W64D, SubArithD, ALUOpD};
if (`ZBS_SUPPORTED) begin: bitmanipi //change the conditional expression to OR any Z supported flags