From f8401a80e92b65271625c55dd24ec83d84314d9c Mon Sep 17 00:00:00 2001
From: ajalali <ayoub.jalali@external.thalesgroup.com>
Date: Wed, 15 Nov 2023 11:32:12 +0100
Subject: [PATCH] Add more constraints to cover corner cases in CC

---
 verif/env/corev-dv/cva6_instr_sequence.sv    |  3 +-
 verif/env/corev-dv/cva6_unsupported_instr.sv | 49 ++++++++++++++++++--
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/verif/env/corev-dv/cva6_instr_sequence.sv b/verif/env/corev-dv/cva6_instr_sequence.sv
index f64b882f654..e0f17ae12d8 100644
--- a/verif/env/corev-dv/cva6_instr_sequence.sv
+++ b/verif/env/corev-dv/cva6_instr_sequence.sv
@@ -45,7 +45,8 @@ class cva6_instr_sequence_c extends riscv_instr_sequence;
                       bin_instr_cnt, cfg_cva6.unsupported_instr_ratio), UVM_LOW)
       repeat (bin_instr_cnt) begin
         `DV_CHECK_RANDOMIZE_WITH_FATAL(unsupported_instr, 
-                                       unsupported_instr inside {rv64i_instr,rv64c_instr,rv64m_instr,rvfdq_instr,illegal_slli_srai,sys_instr};)
+                                       unsupported_instr inside {rv64i_instr, rv64c_instr, rv64m_instr, rvfdq_instr, illegal_slli_srai, sys_instr,
+                                                                 illegal_rv32zcb_instr, rv64zcb_instr, rv32vf_instr};)
         str = {indent, $sformatf(".4byte 0x%s # %0s",
                        unsupported_instr.get_bin_str(), unsupported_instr.comment)};
                idx = $urandom_range(0, instr_string_list.size());
diff --git a/verif/env/corev-dv/cva6_unsupported_instr.sv b/verif/env/corev-dv/cva6_unsupported_instr.sv
index 5cdd74911fd..3ab24dc0405 100644
--- a/verif/env/corev-dv/cva6_unsupported_instr.sv
+++ b/verif/env/corev-dv/cva6_unsupported_instr.sv
@@ -26,13 +26,16 @@ class cva6_unsupported_instr_c extends uvm_object;
 
   string comment;
 
-  typedef enum bit [2:0] {
+  typedef enum bit [3:0] {
     rv64i_instr,
     rv64c_instr,
     rv64m_instr,
     rvfdq_instr,
     sys_instr,
-    illegal_slli_srai
+    illegal_slli_srai,
+    rv64zcb_instr,
+    illegal_rv32zcb_instr,
+    rv32vf_instr
   } illegal_ext_instr_type_e;
 
   // Default legal opcode for RV32I instructions
@@ -119,7 +122,10 @@ class cva6_unsupported_instr_c extends uvm_object;
       rv64m_instr := 3,
       rvfdq_instr := 3,
       sys_instr   := 1,
-      illegal_slli_srai := 1
+      illegal_slli_srai := 1,
+      rv64zcb_instr := 1,
+      illegal_rv32zcb_instr := 1,
+      rv32vf_instr :=1
     };
   }
 
@@ -226,6 +232,15 @@ class cva6_unsupported_instr_c extends uvm_object;
     }
   }
 
+  // RV32 Vectorial FP instructions
+  constraint rv32vf_instr_c {
+    if (unsupported_instr == rv32vf_instr) {
+         compressed == 0;
+         opcode == 7'b0110011;
+         instr_bin[31:30] == 2'b10;
+    }
+  }
+
   // RV64C instructions
   constraint rv64c_instr_c {
     if (!RV64C inside {supported_isa} ||
@@ -259,6 +274,34 @@ class cva6_unsupported_instr_c extends uvm_object;
     }
   }
 
+  // RV64Zcb instructions
+  constraint rv64zcb_instr_c {
+    if (unsupported_instr == rv64zcb_instr) {
+         compressed == 1;
+         c_op  == 2'b01;
+         c_msb == 3'b100;
+         instr_bin[12:10] == 3'b111;
+         instr_bin[6:2] == 5'b11100;
+    }
+  }
+
+  // Illegal RV32Zcb instructions
+  constraint illegal_rv32zcb_instr_c {
+    if (unsupported_instr == illegal_rv32zcb_instr) {
+         compressed == 1;
+         c_op inside {2'b00, 2'b01};
+         c_msb == 3'b100;
+         if (c_op == 2'b00) {
+            !(instr_bin[12:10] inside {3'b000, 3'b001, 3'b010, 3'b011});
+         }
+         if (c_op == 2'b01) {
+            instr_bin[12:10] == 3'b111;
+            !(instr_bin[4:2] inside {3'b000, 3'b001, 3'b010, 3'b011, 3'b100, 3'b101});
+            instr_bin[6:5] == 2'b11;
+         }
+    }
+  }
+
   // RV32FDQ, RV64FDQ instructions
   constraint rvfdq_instr_c {
     if (!RV32F inside {supported_isa} ||