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Merge pull request #24 from antonblanchard/cr_file_cleanup

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Rework CR file and add forwarding
pull/23/head
Anton Blanchard 5 years ago committed by GitHub
parent 7c2a2b7414 9fbaea6f08
commit a5d31bb554
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 37 additions and 45 deletions
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5
common.vhdl
Unescape Escape View File

@ -79,14 +79,11 @@ package common is
end record;

type Decode2ToCrFileType is record
read_cr_nr_1 : integer;
read_cr_nr_2 : integer;
read : std_ulogic;
end record;

type CrFileToDecode2Type is record
read_cr_data : std_ulogic_vector(31 downto 0);
read_cr_data_1 : std_ulogic_vector(3 downto 0);
read_cr_data_2 : std_ulogic_vector(3 downto 0);
end record;

type Execute1ToFetch1Type is record

55
cr_file.vhdl
Unescape Escape View File

@ -18,48 +18,43 @@ end entity cr_file;

architecture behaviour of cr_file is
signal crs : std_ulogic_vector(31 downto 0) := (others => '0');
signal crs_updated : std_ulogic_vector(31 downto 0) := (others => '0');
begin
cr_create_0: process(all)
variable hi, lo : integer := 0;
begin
for i in 0 to 7 loop
if w_in.write_cr_mask(i) = '1' then
lo := i*4;
hi := lo + 3;
crs_updated(hi downto lo) <= w_in.write_cr_data(hi downto lo);
end if;
end loop;
end process;

-- synchronous writes
cr_write_0: process(clk)
variable hi, lo : integer := 0;
begin
if rising_edge(clk) then
if w_in.write_cr_enable = '1' then
report "Writing " & to_hstring(w_in.write_cr_data) & " to CR mask " & to_hstring(w_in.write_cr_mask);

for i in 0 to 7 loop
if w_in.write_cr_mask(i) = '1' then
lo := i*4;
hi := lo + 3;
crs(hi downto lo) <= w_in.write_cr_data(hi downto lo);
end if;
end loop;
crs <= crs_updated;
end if;
end if;
end process cr_write_0;
end process;

-- asynchronous reads
cr_read_0: process(all)
variable hi, lo : integer := 0;
begin
--lo := (7-d_in.read_cr_nr_1)*4;
--hi := lo + 3;

--report "read " & integer'image(d_in.read_cr_nr_1) & " from CR " & to_hstring(crs(hi downto lo));
--d_out.read_cr_data_1 <= crs(hi downto lo);

-- Also return the entire CR to make mfcrf easier for now
report "read CR " & to_hstring(crs);
d_out.read_cr_data <= crs;

-- -- Forward any written data
-- if w_in.write_cr_enable = '1' then
-- if d_in.read_cr_nr_1 = w_in.write_cr_nr then
-- d_out.read_cr_data_1 <= w_in.write_cr_data;
-- end if;
-- if d_in.read_cr_nr_2 = w_in.write_cr_nr then
-- d_out.read_cr_data_2 <= w_in.write_cr_data;
-- end if;
-- end if;
end process cr_read_0;
-- just return the entire CR to make mfcrf easier for now
if d_in.read = '1' then
report "Reading CR " & to_hstring(crs_updated);
end if;
if w_in.write_cr_enable then
d_out.read_cr_data <= crs_updated;
else
d_out.read_cr_data <= crs;
end if;
end process;
end architecture behaviour;

18
decode1.vhdl
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@ -43,19 +43,19 @@ architecture behaviour of decode1 is
PPC_ATTN => (ALU, OP_ILLEGAL, NONE, NONE, NONE, NONE, NONE, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0'),
PPC_B => (ALU, OP_B, NONE, CONST_LI, NONE, NONE, NONE, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1'),
--PPC_BA
PPC_BC => (ALU, OP_BC, NONE, CONST_BD, NONE, NONE, BO, BI, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1'),
PPC_BC => (ALU, OP_BC, NONE, CONST_BD, NONE, NONE, BO, BI, NONE, '1', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1'),
--PPC_BCA
PPC_BCCTR => (ALU, OP_BCCTR, NONE, NONE, NONE, NONE, BO, BI, BH, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1'),
PPC_BCCTR => (ALU, OP_BCCTR, NONE, NONE, NONE, NONE, BO, BI, BH, '1', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1'),
--PPC_BCLA
PPC_BCLR => (ALU, OP_BCLR, NONE, NONE, NONE, NONE, BO, BI, BH, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1'),
PPC_BCLR => (ALU, OP_BCLR, NONE, NONE, NONE, NONE, BO, BI, BH, '1', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1'),
--PPC_BCTAR
--PPC_BPERM
PPC_CMP => (ALU, OP_CMP, RA, RB, NONE, NONE, BF, L, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMPB => (ALU, OP_CMPB, RS, RB, NONE, RA, NONE, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMP => (ALU, OP_CMP, RA, RB, NONE, NONE, BF, L, NONE, '0', '1', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMPB => (ALU, OP_CMPB, RS, RB, NONE, RA, NONE, NONE, NONE, '0', '1', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
--PPC_CMPEQB
PPC_CMPI => (ALU, OP_CMP, RA, CONST_SI, NONE, NONE, BF, L, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMPL => (ALU, OP_CMPL, RA, RB, NONE, NONE, BF, L, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMPLI => (ALU, OP_CMPL, RA, CONST_UI, NONE, NONE, BF, L, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMPI => (ALU, OP_CMP, RA, CONST_SI, NONE, NONE, BF, L, NONE, '0', '1', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMPL => (ALU, OP_CMPL, RA, RB, NONE, NONE, BF, L, NONE, '0', '1', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_CMPLI => (ALU, OP_CMPL, RA, CONST_UI, NONE, NONE, BF, L, NONE, '0', '1', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
--PPC_CMPRB
PPC_CNTLZD => (ALU, OP_CNTLZD, RS, NONE, NONE, RA, NONE, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0'),
PPC_CNTLZW => (ALU, OP_CNTLZW, RS, NONE, NONE, RA, NONE, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0'),
@ -90,7 +90,7 @@ architecture behaviour of decode1 is
--PPC_EXTSWSLI
--PPC_ICBI
PPC_ICBT => (ALU, OP_NOP, NONE, NONE, NONE, NONE, NONE, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_ISEL => (ALU, OP_ISEL, RA_OR_ZERO, RB, NONE, RT, BC, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_ISEL => (ALU, OP_ISEL, RA_OR_ZERO, RB, NONE, RT, BC, NONE, NONE, '1', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_ISYNC => (ALU, OP_NOP, NONE, NONE, NONE, NONE, NONE, NONE, NONE, '0', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0'),
PPC_LBARX => (LDST, OP_LOAD, RA, RB, NONE, RT, NONE, NONE, NONE, '0', '0', '0', '0', is1B, '0', '0', '0', '1', '0', '0', NONE, '0'),
--CONST_LI matches CONST_SI, so reuse it

2
decode2.vhdl
Unescape Escape View File

@ -184,6 +184,8 @@ begin
r_out.read3_reg <= insn_rs(d.insn) when d.decode.input_reg_c = RS else
(others => '0');

c_out.read <= d.decode.input_cr;

decode2_1: process(all)
variable mul_a : std_ulogic_vector(63 downto 0);
variable mul_b : std_ulogic_vector(63 downto 0);

2
writeback.vhdl
Unescape Escape View File

@ -56,7 +56,6 @@ begin
end if;

if e.write_cr_enable = '1' then
report "Writing CR ";
c_tmp.write_cr_enable <= '1';
c_tmp.write_cr_mask <= e.write_cr_mask;
c_tmp.write_cr_data <= e.write_cr_data;
@ -81,7 +80,6 @@ begin
w_tmp.write_data <= m.write_reg_data;
end if;
if m.write_cr_enable = '1' then
report "Writing CR ";
c_tmp.write_cr_enable <= '1';
c_tmp.write_cr_mask <= m.write_cr_mask;
c_tmp.write_cr_data <= m.write_cr_data;

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