From 303331cc8fa1253ea599c3352905c3f38984baae Mon Sep 17 00:00:00 2001
From: Yuecheng-CAM <yw737@cam.ac.uk>
Date: Sun, 20 Oct 2024 23:17:01 +0100
Subject: [PATCH] implement C_GET_HIGH

---
 src_Core/ISA/ISA_Decls_CHERI.bsv           | 1 +
 src_Core/RISCY_OOO/procs/lib/Decode.bsv    | 6 ++++++
 src_Core/RISCY_OOO/procs/lib/Exec.bsv      | 6 ++++++
 src_Core/RISCY_OOO/procs/lib/ProcTypes.bsv | 1 +
 4 files changed, 14 insertions(+)

diff --git a/src_Core/ISA/ISA_Decls_CHERI.bsv b/src_Core/ISA/ISA_Decls_CHERI.bsv
index 3dbd9dd..21ee1a7 100755
--- a/src_Core/ISA/ISA_Decls_CHERI.bsv
+++ b/src_Core/ISA/ISA_Decls_CHERI.bsv
@@ -184,6 +184,7 @@ Bit #(5) f5rs2_cap_CGetAddr    = 5'h0f;
 Bit #(5) f5rs2_cap_CClearFPReg = 5'h10;
 Bit #(5) f5rs2_cap_CSealEntry  = 5'h11;
 Bit #(5) f5rs2_cap_CLoadTags   = 5'h12;
+Bit #(5) f5rs2_cap_CGetHigh    = 5'h17;
 // 5'h13 unused
 Bit #(5) f5rs2_cap_JALR_PCC    = 5'h14;
 // 5'h15-5'h1f unused (5'h1f reserved for 1-reg instructions)
diff --git a/src_Core/RISCY_OOO/procs/lib/Decode.bsv b/src_Core/RISCY_OOO/procs/lib/Decode.bsv
index 8712175..ac3c73e 100644
--- a/src_Core/RISCY_OOO/procs/lib/Decode.bsv
+++ b/src_Core/RISCY_OOO/procs/lib/Decode.bsv
@@ -1303,6 +1303,12 @@ function DecodeResult decode(Instruction inst, Bool cap_mode);
                                     regs.src1 = Valid(tagged Gpr rs1);
                                     dInst.capFunc = CapInspect (GetType);
                                 end
+                                f5rs2_cap_CGetHigh: begin
+                                    dInst.iType = Cap;
+                                    regs.dst = Valid(tagged Gpr rd);
+                                    regs.src1 = Valid(tagged Gpr rs1);
+                                    dInst.capFunc = CapInspect (GetHigh);
+                                end
                                 f5rs2_cap_CLoadTags: begin
                                     dInst.iType = Ld;
                                     dInst.imm = Valid(0);
diff --git a/src_Core/RISCY_OOO/procs/lib/Exec.bsv b/src_Core/RISCY_OOO/procs/lib/Exec.bsv
index c408936..e4b25c5 100644
--- a/src_Core/RISCY_OOO/procs/lib/Exec.bsv
+++ b/src_Core/RISCY_OOO/procs/lib/Exec.bsv
@@ -308,6 +308,8 @@ function Data capInspect(CapPipe a, CapPipe b, CapInspectFunc func);
                    zeroExtend(getFlags(a));
                tagged GetPerm                :
                    zeroExtend(getPerms(a));
+               tagged GetHigh                : 
+                   zeroExtend(getHigh(pack(toMem(a))));
                tagged GetType                :
                    tpl_1(extractType(a));
                tagged ToPtr                  :
@@ -624,7 +626,11 @@ function MemTaggedData gatherLoad( Addr addr, ByteOrTagEn byteOrTagEn
         return dataToMemTaggedData(extend(dataVec[offset]));
     end
 endfunction
+function Bit#(64) getHigh(CapMem cap);
+    Bit #(129) cap_mem_bits = unpack(pack(cap));
+    return cap_mem_bits[128-1:64];
 
+endfunction 
 function Tuple2#(ByteEn, Data) scatterStore(Addr addr, ByteEn byteEn, Data data);
     Bit#(IndxShamt) offset = truncate(addr);
     if(byteEn[7]) begin
diff --git a/src_Core/RISCY_OOO/procs/lib/ProcTypes.bsv b/src_Core/RISCY_OOO/procs/lib/ProcTypes.bsv
index 208a2e6..fdb4da5 100644
--- a/src_Core/RISCY_OOO/procs/lib/ProcTypes.bsv
+++ b/src_Core/RISCY_OOO/procs/lib/ProcTypes.bsv
@@ -363,6 +363,7 @@ typedef union tagged {
     void GetFlags;
     void GetPerm;
     void GetType;
+    void GetHigh;
     void ToPtr;
 } CapInspectFunc deriving(Bits, Eq, FShow);