@ -89,8 +89,8 @@ architecture behaviour of decode1 is
28 => (ALU, NONE, OP_AND, NONE, CONST_UI, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', ONE, '0', '0', NONE), -- andi.
29 => (ALU, NONE, OP_AND, NONE, CONST_UI_HI, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', ONE, '0', '0', NONE), -- andis.
0 => (ALU, NONE, OP_ATTN, NONE, NONE, NONE, NONE, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '1', NONE), -- attn
18 => (ALU, NONE, OP_B, NONE, CONST_LI, NONE, SPR, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE), -- b
16 => (ALU, NONE, OP_BC, SPR, CONST_BD, NONE, SPR , '1', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE), -- bc
18 => (ALU, NONE, OP_B, NONE, CONST_LI, NONE, NONE, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE), -- b
16 => (ALU, NONE, OP_BC, NONE, CONST_BD, NONE, NONE, '1', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE), -- bc
11 => (ALU, NONE, OP_CMP, RA, CONST_SI, NONE, NONE, '0', '1', '1', '0', ONE, '0', NONE, '0', '0', '0', '0', '0', '1', NONE, '0', '0', NONE), -- cmpi
10 => (ALU, NONE, OP_CMP, RA, CONST_UI, NONE, NONE, '0', '1', '1', '0', ONE, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE), -- cmpli
34 => (LDST, NONE, OP_LOAD, RA_OR_ZERO, CONST_SI, NONE, RT, '0', '0', '0', '0', ZERO, '0', is1B, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE), -- lbz
@ -177,7 +177,7 @@ architecture behaviour of decode1 is
-- addpcis
2#001# => (ALU, NONE, OP_ADD, CIA, CONST_DXHI4, NONE, RT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
-- bclr, bcctr, bctar
2#100# => (ALU, NONE, OP_BCREG, SPR, SPR, NONE, SPR, '1', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE),
2#100# => (ALU, NONE, OP_BCREG, NONE, NONE, NONE, SPR, '1', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE),
-- isync
2#111# => (ALU, NONE, OP_ISYNC, NONE, NONE, NONE, NONE, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
-- rfid
@ -530,6 +530,13 @@ architecture behaviour of decode1 is
begin
ret := (index => 0, isodd => '0', valid => '1');
case sprn is
when SPR_LR =>
ret.index := RAMSPR_LR;
when SPR_CTR =>
ret.index := RAMSPR_CTR;
ret.isodd := '1';
when SPR_TAR =>
ret.index := RAMSPR_TAR;
when SPR_SRR0 =>
ret.index := RAMSPR_SRR0;
when SPR_SRR1 =>
@ -683,13 +690,6 @@ begin
end if;
when 16 =>
-- CTR may be needed as input to bc
if f_in.insn(23) = '0' then
v.ispr1 := fast_spr_num(SPR_CTR);
v.ispro := fast_spr_num(SPR_CTR);
elsif f_in.insn(0) = '1' then
v.ispro := fast_spr_num(SPR_LR);
end if;
-- Predict backward branches as taken, forward as untaken
v.br_pred := f_in.insn(15);
br_offset := resize(signed(f_in.insn(15 downto 2)), 24);
@ -698,37 +698,12 @@ begin
-- Unconditional branches are always taken
v.br_pred := '1';
br_offset := signed(f_in.insn(25 downto 2));
if f_in.insn(0) = '1' then
v.ispro := fast_spr_num(SPR_LR);
end if;
when 19 =>
vi.override := not decode_op_19_valid(to_integer(unsigned(f_in.insn(5 downto 1) & f_in.insn(10 downto 6))));
op_19_bits := f_in.insn(5) & f_in.insn(3) & f_in.insn(2);
v.decode := decode_op_19_array(to_integer(unsigned(op_19_bits)));
-- Work out ispr1/ispr2 independent of v.decode since they seem to be critical path
if f_in.insn(2) = '0' then
-- Could be OP_BCREG: bclr, bcctr, bctar
-- Branch uses CTR as condition when BO(2) is 0. This is
-- also used to indicate that CTR is modified (they go
-- together).
-- bcctr doesn't update CTR or use it in the branch condition
if f_in.insn(23) = '0' and (f_in.insn(10) = '0' or f_in.insn(6) = '1') then
v.ispr1 := fast_spr_num(SPR_CTR);
v.ispro := fast_spr_num(SPR_CTR);
elsif f_in.insn(0) = '1' then
v.ispro := fast_spr_num(SPR_LR);
end if;
if f_in.insn(10) = '0' then
v.ispr2 := fast_spr_num(SPR_LR);
elsif f_in.insn(6) = '0' then
v.ispr2 := fast_spr_num(SPR_CTR);
else
v.ispr2 := fast_spr_num(SPR_TAR);
end if;
end if;
when 24 =>
-- ori, special-case the standard NOP
if std_match(f_in.insn, "01100000000000000000000000000000") then