Cheri-research/Toooba
1
0
Fork 0
Code Issues 1 Pull Requests Actions Packages Projects Releases Wiki Activity

Ban illegal shift immediate encodings

Browse Source
This commit is contained in:
Peter Rugg
2025-01-23 12:24:28 +00:00
committed by PeterRugg
parent 773d5c1107
commit 8d0f985d99
1 changed files with 8 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
src_Core/RISCY_OOO/procs/lib/Decode.bsv
View File

@@ -338,8 +338,10 @@ function DecodeResult decode(Instruction inst, Bool cap_mode);
fnAND: Valid(And);
fnOR: Valid(Or);
fnXOR: Valid(Xor);
fnSLL: Valid(Sll);
fnSR: Valid(immI[10] == 0 ? Srl : Sra);
fnSLL: (immI[11:6] == 6'b000000 ? Valid(Sll) : Invalid);
fnSR: (immI[11:6] == 6'b000000 ? Valid(Srl) :
immI[11:6] == 6'b010000 ? Valid(Sra) :
Invalid);
default: Invalid;
endcase;
legalInst = isValid(mAluFunc);
@@ -355,8 +357,10 @@ function DecodeResult decode(Instruction inst, Bool cap_mode);
dInst.iType = Alu;
Maybe#(AluFunc) mAluFunc = case (funct3)
fnADD: Valid(Addw);
fnSLL: Valid(Sllw);
fnSR: Valid(immI[10] == 0 ? Srlw : Sraw);
fnSLL: (immI[11:5] == 7'b0000000 ? Valid(Sllw) : Invalid);
fnSR: (immI[11:5] == 7'b0000000 ? Valid(Srlw) :
immI[11:5] == 7'b0100000 ? Valid(Sraw) :
Invalid);
default: Invalid;
endcase;
legalInst = isValid(mAluFunc);