From: Luke Kenneth Casson Leighton Date: Sat, 23 Jan 2021 20:44:58 +0000 (+0000) Subject: start decoding modes in svp64 X-Git-Tag: 24jan2021_ls180~6 X-Git-Url: https://git.libre-soc.org/?p=soc.git;a=commitdiff_plain;h=cdd91a801bdc5372c14d0ce6a9e000835baaba64 start decoding modes in svp64 --- diff --git a/src/soc/sv/trans/svp64.py b/src/soc/sv/trans/svp64.py index 7fe92317..3ad6a5f2 100644 --- a/src/soc/sv/trans/svp64.py +++ b/src/soc/sv/trans/svp64.py @@ -106,6 +106,29 @@ def decode_predicate(encoding): return pmap[encoding] +# decodes "Mode" in similar way to BO field (supposed to, anyway) +def decode_bo(encoding): + pmap = { # TODO: double-check that these are the same as Branch BO + 'lt' : 0b000, + 'nl' : 0b001, 'ge' : 0b001, # same value + 'gt' : 0b010, + 'ng' : 0b011, 'le' : 0b011, # same value + 'eq' : 0b100, + 'ne' : 0b101, + 'so' : 0b110, 'un' : 0b110, # same value + 'ns' : 0b111, 'nu' : 0b111, # same value + } + assert encoding in pmap, \ + "encoding %s for BO Mode not recognised" % encoding + return pmap[encoding] + +# partial-decode fail-first mode +def decode_ffirst(encoding): + if encoding in ['RC1', '~RC1']: + return encoding + return decode_bo(encoding) + + # gets SVP64 ReMap information class SVP64RM: def __init__(self): @@ -144,10 +167,21 @@ class SVP64: if not opcode.startswith('sv.'): res.append(insn) # unaltered continue + opcode = opcode[3:] # strip leading "sv." + + # start working on decoding the svp64 op: sv.baseop/vec2.mode + opcode = opcode.split("/") # split at "/" + v30b_op = opcode[0] # first is the v3.0B + if len(opcode) == 1: + opmodes = [] # no sv modes + else: + opmodes = opcode[1].split(".") # second splits by dots + + # check instruction ends with dot + rc_mode = v30b_op.endswith('.') + if rc_mode: + v30b_op = v30b_op[:-1] - # start working on decoding the svp64 op: sv.baseop.vec2.mode - opmodes = opcode.split(".")[1:] # strip leading "sv." - v30b_op = opmodes.pop(0) # first is the v3.0B if v30b_op not in isa.instr: raise Exception("opcode %s of '%s' not supported" % \ (v30b_op, insn)) @@ -157,6 +191,7 @@ class SVP64: isa.instr[v30b_op].regs[0] v30b_regs = isa.instr[v30b_op].regs[0] rm = svp64.instrs[v30b_op] + print ("v3.0B op", v30b_op, "Rc=1" if rc_mode else '') print ("v3.0B regs", opcode, v30b_regs) print (rm) @@ -363,6 +398,18 @@ class SVP64: has_pmask = False has_smask = False + saturation = None + src_zero = 0 + dst_zero = 0 + sv_mode = None + + mapreduce = False + mapreduce_crm = False + mapreduce_svm = False + + predresult = False + failfirst = False + # ok let's start identifying opcode augmentation fields for encmode in opmodes: # predicate mask (dest) @@ -385,6 +432,82 @@ class SVP64: destwid = decode_elwidth(encmode[3:]) elif encmode.startswith("sw="): srcwid = decode_elwidth(encmode[3:]) + # saturation + elif encmode == 'sats': + assert sv_mode is None + saturation = 1 + sv_mode = 0b10 + elif encmode == 'satu': + assert sv_mode is None + sv_mode = 0b10 + saturation = 0 + # predicate zeroing + elif encmode == 'sz': + src_zero = 1 + elif encmode == 'dz': + dst_zero = 1 + # failfirst + elif encmode.startswith("ff="): + assert sv_mode is None + sv_mode = 0b01 + failfirst = decode_ffirst(encmode[3:]) + # predicate-result, interestingly same as fail-first + elif encmode.startswith("pr="): + assert sv_mode is None + sv_mode = 0b11 + predresult = decode_ffirst(encmode[3:]) + # map-reduce mode + elif encmode == 'mr': + assert sv_mode is None + sv_mode = 0b00 + mapreduce = True + elif encmode == 'crm': # CR on map-reduce + assert sv_mode is None + sv_mode = 0b00 + mapreduce_crm = True + elif encmode == 'svm': # sub-vector mode + mapreduce_svm = True + + # construct the mode field, doing sanity-checking along the way + + if mapreduce_svm: + assert sv_mode == 0b00, "sub-vector mode in mapreduce only" + assert subvl != 0, "sub-vector mode not possible on SUBVL=1" + + # "normal" mode + if sv_mode is None: + mode |= (src_zero << 3) | (dst_zero << 4) + + # "mapreduce" modes + elif sv_mode == 0b00: + mode |= (0b1<<2) # sets mapreduce + assert dst_zero == 0, "dest-zero not allowed in mapreduce mode" + if mapreduce_crm: + mode |= (0b1<<4) # sets CRM mode + assert rc_mode, "CRM only allowed when Rc=1" + # bit of weird encoding to jam zero-pred or SVM mode in. + # SVM mode can be enabled only when SUBVL=2/3/4 (vec2/3/4) + if subvl == 0: + mode |= (src_zero << 3) # predicate src-zeroing + elif mapreduce_svm: + mode |= (1 << 3) # SVM mode + + # "failfirst" modes + elif sv_mode == 0b01: + assert dst_zero == 0, "dest-zero not allowed in failfirst mode" + mode |= 0b01 # sets failfirst + if failfirst == 'RC1': + mode |= (0b1<<4) # sets RC1 mode + mode |= (src_zero << 3) # predicate src-zeroing + assert rc_mode==False, "ffirst RC1 only possible when Rc=0" + elif failfirst == '~RC1': + mode |= (0b1<<4) # sets RC1 mode... + mode |= (src_zero << 3) # predicate src-zeroing + mode |= (0b1<<2) # ... with inversion + assert rc_mode==False, "ffirst RC1 only possible when Rc=0" + else: + assert src_zero == 0, "src-zero not allowed in ffirst BO" + mode |= (failfirst << 2) # set BO # sanity-check that 2Pred mask is same mode if has_pmask and has_smask: @@ -418,6 +541,7 @@ class SVP64: print (" dstwid 4-5 :", bin(destwid)) print (" srcwid 6-7 :", bin(srcwid)) print (" subvl 8-9 :", bin(subvl)) + print (" mode 19-23:", bin(mode)) offs = 2 if etype == 'EXTRA2' else 3 # 2 or 3 bits for idx, sv_extra in extras.items(): if idx is None: continue @@ -438,8 +562,9 @@ if __name__ == '__main__': 'sv.cmpi 5, 1, 3, 2', 'sv.setb 5, 31', 'sv.isel 64.v, 3, 2, 65.v', - 'sv.setb.m=r3.sm=1<