Merge pull request #565 from davidharrishmc/dev

Dev

bin/wally-tool-chain-install.sh

@@ -137,6 +137,27 @@ sudo make install
 # package manager. Sail has so many dependencies that it can be difficult to install.
 # This script works for Ubuntu.
 
+# Alex Solomatnikov found these commands worked to build Sail for Centos 8 on 1/12/24
+#sudo su -
+#dnf install ocaml.x86_64
+#pip3 install z3-solver
+#wget https://raw.githubusercontent.com/ocaml/opam/master/shell/install.sh
+#sh install.sh
+#opam init
+#exit
+#ocaml -version
+#opam switch create 5.1.0
+#eval $(opam config env)
+#git clone --recurse-submodules git@github.com:riscv/sail-riscv.git
+#cd sail-riscv
+#make
+#ARCH=RV32 make
+#ARCH=RV64 make
+#git log -1
+#cp -p c_emulator/riscv_sim_RV* /tools/sail-riscv/d7a3d8012fd579f40e53a29569141d72dd5e0c32/bin/.
+
+
+# This was an earlier attemp to prepare to install Sail on RedHat 8
 # Do these commands only for RedHat / Rocky 8 to build from source.
 #cd $RISCV
 #git clone https://github.com/Z3Prover/z3.git

src/ieu/alu.sv

@@ -101,11 +101,16 @@ module alu import cvw::*; #(parameter cvw_t P) (
 
   // Zicond block
   if (P.ZICOND_SUPPORTED) begin: zicond
-    logic  BZero, KillB;
+    logic  BZero;
+    
     assign BZero = (B == 0); // check if rs2 = 0
     // Create a signal that is 0 when czero.* instruction should clear result
     // If B = 0 for czero.eqz or if B != 0 for czero.nez
-    assign KillB = BZero & CZero[0] | ~BZero & CZero[1];
-    assign ZeroCondMaskInvB = |CZero ? {P.XLEN{~KillB}} : CondMaskInvB; // extend to full width
+    always_comb 
+     case (CZero)
+        2'b01:   ZeroCondMaskInvB = {P.XLEN{~BZero}}; // czero.eqz: kill if B = 0
+        2'b10:   ZeroCondMaskInvB = {P.XLEN{BZero}};  // czero.nez: kill if B != 0
+        default: ZeroCondMaskInvB = CondMaskInvB;     // otherwise normal behavior
+      endcase
   end else assign ZeroCondMaskInvB = CondMaskInvB; // no masking if Zicond is not supported
 endmodule