Hi Richard,
On 2021/11/12 下午10:05, Richard Henderson wrote:
On 11/12/21 7:53 AM, Song Gao wrote:
+#
+# Fields
+#
+%rd 0:5
+%rj 5:5
+%rk 10:5
+%sa2 15:2
+%si12 10:s12
+%ui12 10:12
+%si16 10:s16
+%si20 5:s20
You should only create separate field definitions like this when they
are complex: e.g. the logical field is disjoint or there's a need for
!function.
+
+#
+# Argument sets
+#
+&fmt_rdrjrk rd rj rk
+&fmt_rdrjsi12 rd rj si12
+&fmt_rdrjrksa2 rd rj rk sa2
+&fmt_rdrjsi16 rd rj si16
+&fmt_rdrjui12 rd rj ui12
+&fmt_rdsi20 rd si20
Some of these should be combined. The width of the immediate is a
detail of the format, not the decoded argument set. Thus you should have
&fmt_rdimm rd imm
&fmt_rdrjimm rd rj imm
&fmt_rdrjrk rd rj rk
&fmt_rdrjrksa rd rj rk sa
'The width of the immediate is a detail of the format' means:
&fmt_rdrjimm rd rj imm
@fmt_rdrjimm .... ...... imm:12 rj:5 rd:5 &fmt_rdrjimm
@fmt_rdrjimm14 .... .... imm:14 rj:5 rd:5 &fmt_rdrjimm
@fmt_rdrjimm16 .... .. imm:16 rj:5 rd:5 &fmt_rdrjimm
and we print in the disassembly, liks this
output_rdrjimm(DisasContext *ctx, arg_fmt_rdrjimm * a, const char *mnemonic)
{
output(ctx, mnemonic, "%s, %s, 0x%x", regnames[a->rd], regnames[a->rj],
a->imm);
}
is that right?
+alsl_w 0000 00000000 010 .. ..... ..... .....
@fmt_rdrjrksa2
+alsl_wu 0000 00000000 011 .. ..... ..... .....
@fmt_rdrjrksa2
+alsl_d 0000 00000010 110 .. ..... ..... .....
@fmt_rdrjrksa2
The encoding of these insns is that the shift is sa+1.
While you compensate for this in gen_alsl_*, we print the "wrong"
number in the disassembly. I think it would be better to do
%sa2p1 15:2 !function=plus_1
@fmt_rdrjrksa2p1 .... ........ ... .. rk:5 rj:5 rd:5 \
&fmt_rdrjrksa sa=%sa2p1
1. We print sa in disassembly output_rdrjrksa(DisasContext *ctx,
arg_fmt_rdrjsa* a, const char *memonic) { output(ctx, memonic, "%s, %s,
%s, 0x0x", regnames[a->rd], regnames[a->rj], a->sa) } 2. We use sa on
gen_alsl_* not (sa2+1). 3 bytepick_w use the same print functions. but
the Field/Argurment/Format is %sa2 15:2 &fmt_rdrjrksa rd rj sa
@fmt_rdrjrk sa2 .... ........ ... sa:2 rk:5 rj:5 rd:5 &fmt_rdrjrksa Is
my understanding right? Thanks. Song Gao