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Implement byte reversal instructions

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This implements the byte-reverse halfword, word and doubleword
instructions: brh, brw, and brd.  These instructions were added to the
ISA in version 3.1.  They use a new OP_BREV insn_type value.  The
logic for these instructions is implemented in logical.vhdl.

In order to avoid going over 64 insn_type values, OP_AND and OP_OR
were combined into OP_LOGIC, which is like OP_AND except that the RS
input can be inverted as well as the RB input.  The various forms of
OR instruction are then implemented using the identity

    a OR b = NOT (NOT a AND NOT b)

The 'is_signed' field of the instruction decode table is used to
indicate that RS should be inverted.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
pull/419/head
Paul Mackerras 1 year ago
parent fd8c0000c0
commit b50170cd1d
6 changed files with 71 additions and 45 deletions
Show Stats Download Patch File Download Diff File

23
decode1.vhdl
Unescape Escape View File

@ -89,10 +89,10 @@ architecture behaviour of decode1 is
INSN_addme => (ALU, NONE, OP_ADD, RA, CONST_M1, NONE, RT, '0', '0', '0', '0', CA, '1', NONE, '0', '0', '0', '0', '0', '0', RCOE, '0', '0', NONE),
INSN_addpcis => (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),
INSN_addze => (ALU, NONE, OP_ADD, RA, NONE, NONE, RT, '0', '0', '0', '0', CA, '1', NONE, '0', '0', '0', '0', '0', '0', RCOE, '0', '0', NONE),
INSN_and => (ALU, NONE, OP_AND, NONE, RB, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_andc => (ALU, NONE, OP_AND, NONE, RB, RS, RA, '0', '0', '1', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_andi_dot => (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),
INSN_andis_dot => (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),
INSN_and => (ALU, NONE, OP_LOGIC, NONE, RB, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_andc => (ALU, NONE, OP_LOGIC, NONE, RB, RS, RA, '0', '0', '1', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_andi_dot => (ALU, NONE, OP_LOGIC, NONE, CONST_UI, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', ONE, '0', '0', NONE),
INSN_andis_dot => (ALU, NONE, OP_LOGIC, NONE, CONST_UI_HI, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', ONE, '0', '0', NONE),
INSN_attn => (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),
INSN_b => (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),
INSN_bc => (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),
@ -100,6 +100,9 @@ architecture behaviour of decode1 is
INSN_bclr => (ALU, NONE, OP_BCREG, NONE, NONE, NONE, NONE, '1', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE),
INSN_bctar => (ALU, NONE, OP_BCREG, NONE, NONE, NONE, NONE, '1', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '1', '0', NONE),
INSN_bperm => (ALU, NONE, OP_BPERM, NONE, RB, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_brh => (ALU, NONE, OP_BREV, NONE, NONE, RS, RA, '0', '0', '0', '0', ZERO, '0', is2B, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_brw => (ALU, NONE, OP_BREV, NONE, NONE, RS, RA, '0', '0', '0', '0', ZERO, '0', is4B, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_brd => (ALU, NONE, OP_BREV, NONE, NONE, RS, RA, '0', '0', '0', '0', ZERO, '0', is8B, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_cbcdtd => (ALU, NONE, OP_BCD, NONE, NONE, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_cdtbcd => (ALU, NONE, OP_BCD, NONE, NONE, RS, RA, '0', '0', '1', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_cmp => (ALU, NONE, OP_CMP, RA, RB, NONE, NONE, '0', '1', '1', '0', ONE, '0', NONE, '0', '0', '0', '0', '0', '1', NONE, '0', '0', NONE),
@ -268,14 +271,14 @@ architecture behaviour of decode1 is
INSN_mulld => (ALU, NONE, OP_MUL_L64, RA, RB, NONE, RT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '1', RCOE, '0', '0', NONE),
INSN_mulli => (ALU, NONE, OP_MUL_L64, RA, CONST_SI, NONE, RT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '1', NONE, '0', '0', NONE),
INSN_mullw => (ALU, NONE, OP_MUL_L64, RA, RB, NONE, RT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '1', '1', RCOE, '0', '0', NONE),
INSN_nand => (ALU, NONE, OP_AND, NONE, RB, RS, RA, '0', '0', '0', '1', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_nand => (ALU, NONE, OP_LOGIC, NONE, RB, RS, RA, '0', '0', '0', '1', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_neg => (ALU, NONE, OP_ADD, RA, NONE, NONE, RT, '0', '0', '1', '0', ONE, '0', NONE, '0', '0', '0', '0', '0', '0', RCOE, '0', '0', NONE),
INSN_nop => (ALU, NONE, OP_NOP, NONE, NONE, NONE, NONE, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_nor => (ALU, NONE, OP_OR, NONE, RB, RS, RA, '0', '0', '0', '1', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_or => (ALU, NONE, OP_OR, NONE, RB, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_orc => (ALU, NONE, OP_OR, NONE, RB, RS, RA, '0', '0', '1', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0', NONE),
INSN_ori => (ALU, NONE, OP_OR, NONE, CONST_UI, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_oris => (ALU, NONE, OP_OR, NONE, CONST_UI_HI, RS, RA, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_nor => (ALU, NONE, OP_LOGIC, NONE, RB, RS, RA, '0', '0', '1', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '1', RC, '0', '0', NONE),
INSN_or => (ALU, NONE, OP_LOGIC, NONE, RB, RS, RA, '0', '0', '1', '1', ZERO, '0', NONE, '0', '0', '0', '0', '0', '1', RC, '0', '0', NONE),
INSN_orc => (ALU, NONE, OP_LOGIC, NONE, RB, RS, RA, '0', '0', '0', '1', ZERO, '0', NONE, '0', '0', '0', '0', '0', '1', RC, '0', '0', NONE),
INSN_ori => (ALU, NONE, OP_LOGIC, NONE, CONST_UI, RS, RA, '0', '0', '1', '1', ZERO, '0', NONE, '0', '0', '0', '0', '0', '1', NONE, '0', '0', NONE),
INSN_oris => (ALU, NONE, OP_LOGIC, NONE, CONST_UI_HI, RS, RA, '0', '0', '1', '1', ZERO, '0', NONE, '0', '0', '0', '0', '0', '1', NONE, '0', '0', NONE),
INSN_paddi => (ALU, NONE, OP_ADD, RA0_OR_CIA, CONST_PSI, NONE, RT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_plbz => (LDST, NONE, OP_LOAD, RA0_OR_CIA, CONST_PSI, NONE, RT, '0', '0', '0', '0', ZERO, '0', is1B, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),
INSN_pld => (LDST, NONE, OP_LOAD, RA0_OR_CIA, CONST_PSI, NONE, RT, '0', '0', '0', '0', ZERO, '0', is8B, '0', '0', '0', '0', '0', '0', NONE, '0', '0', NONE),

4
decode2.vhdl
Unescape Escape View File

@ -205,13 +205,13 @@ architecture behaviour of decode2 is
type mux_select_array_t is array(insn_type_t) of std_ulogic_vector(2 downto 0);

constant result_select : mux_select_array_t := (
OP_AND => "001", -- logical_result
OP_OR => "001",
OP_LOGIC => "001", -- logical_result
OP_XOR => "001",
OP_PRTY => "001",
OP_CMPB => "001",
OP_EXTS => "001",
OP_BPERM => "001",
OP_BREV => "001",
OP_BCD => "001",
OP_MTSPR => "001",
OP_RLC => "010", -- rotator_result

44
decode_types.vhdl
Unescape Escape View File

@ -3,8 +3,9 @@ use ieee.std_logic_1164.all;

package decode_types is
type insn_type_t is (OP_ILLEGAL, OP_NOP, OP_ADD,
OP_AND, OP_ATTN, OP_B, OP_BC, OP_BCREG,
OP_BCD, OP_BPERM, OP_CMP, OP_CMPB, OP_CMPEQB, OP_CMPRB,
OP_ATTN, OP_B, OP_BC, OP_BCREG,
OP_BCD, OP_BPERM, OP_BREV,
OP_CMP, OP_CMPB, OP_CMPEQB, OP_CMPRB,
OP_CNTZ, OP_CROP,
OP_DARN, OP_DCBF, OP_DCBST, OP_DCBT, OP_DCBTST,
OP_DCBZ, OP_ICBI, OP_ICBT,
@ -12,10 +13,11 @@ package decode_types is
OP_DIV, OP_DIVE, OP_MOD,
OP_EXTS, OP_EXTSWSLI,
OP_ISEL, OP_ISYNC,
OP_LOGIC,
OP_LOAD, OP_STORE,
OP_MCRXRX, OP_MFCR, OP_MFMSR, OP_MFSPR,
OP_MTCRF, OP_MTMSRD, OP_MTSPR, OP_MUL_L64,
OP_MUL_H64, OP_MUL_H32, OP_OR,
OP_MUL_H64, OP_MUL_H32,
OP_POPCNT, OP_PRTY, OP_RFID,
OP_RLC, OP_RLCL, OP_RLCR, OP_SC, OP_SETB,
OP_SHL, OP_SHR,
@ -50,84 +52,84 @@ package decode_types is
INSN_bcctr,
INSN_bclr,
INSN_bctar,
INSN_brh,
INSN_brw,
INSN_brd, -- 20
INSN_cbcdtd,
INSN_cdtbcd,
INSN_cmpi, -- 20
INSN_cmpi,
INSN_cmpli,
INSN_cntlzw,
INSN_cntlzd,
INSN_cnttzw,
INSN_cnttzd,
INSN_crand,
INSN_crandc,
INSN_crandc, -- 30
INSN_creqv,
INSN_crnand,
INSN_crnor, -- 30
INSN_crnor,
INSN_cror,
INSN_crorc,
INSN_crxor,
INSN_darn,
INSN_eieio,
INSN_extsb,
INSN_extsh,
INSN_extsh, -- 40
INSN_extsw,
INSN_extswsli,
INSN_isync, -- 40
INSN_isync,
INSN_lbzu,
INSN_ld,
INSN_ldu,
INSN_lhau,
INSN_lwa,
INSN_lwzu,
INSN_mcrf,
INSN_mcrf, -- 50
INSN_mcrxrx,
INSN_mfcr,
INSN_mfmsr, -- 50
INSN_mfmsr,
INSN_mfspr,
INSN_mtcrf,
INSN_mtmsr,
INSN_mtmsrd,
INSN_mtspr,
INSN_mulli,
INSN_neg,
INSN_neg, -- 60
INSN_nop,
INSN_ori,
INSN_oris, -- 60
INSN_oris,
INSN_popcntb,
INSN_popcntw,
INSN_popcntd,
INSN_prtyw,
INSN_prtyd,
INSN_rfid,
INSN_rldic,
INSN_rldic, -- 70
INSN_rldicl,
INSN_rldicr,
INSN_rldimi, -- 70
INSN_rldimi,
INSN_rlwimi,
INSN_rlwinm,
INSN_sc,
INSN_setb,
INSN_slbia,
INSN_sradi,
INSN_srawi,
INSN_srawi, -- 80
INSN_stbu,
INSN_std,
INSN_stdu, -- 80
INSN_stdu,
INSN_sthu,
INSN_stwu,
INSN_subfic,
INSN_subfme,
INSN_subfze,
INSN_sync,
INSN_tdi,
INSN_tdi, -- 90
INSN_tlbsync,
INSN_twi,
INSN_wait, -- 90
INSN_wait,
INSN_xori,
INSN_xoris,
INSN_93, -- padding
INSN_94,
INSN_95,

-- Non-prefixed instructions that have a MLS:D prefixed form and
-- their corresponding prefixed instructions.

5
execute1.vhdl
Unescape Escape View File

@ -392,6 +392,7 @@ begin
op => e_in.insn_type,
invert_in => e_in.invert_a,
invert_out => e_in.invert_out,
is_signed => e_in.is_signed,
result => logical_result,
datalen => e_in.data_len
);
@ -1105,8 +1106,8 @@ begin
when OP_ADDG6S =>
when OP_CMPRB =>
when OP_CMPEQB =>
when OP_AND | OP_OR | OP_XOR | OP_PRTY | OP_CMPB | OP_EXTS |
OP_BPERM | OP_BCD =>
when OP_LOGIC | OP_XOR | OP_PRTY | OP_CMPB | OP_EXTS |
OP_BPERM | OP_BREV | OP_BCD =>

when OP_B =>
v.take_branch := '1';

37
logical.vhdl
Unescape Escape View File

@ -13,6 +13,7 @@ entity logical is
op : in insn_type_t;
invert_in : in std_ulogic;
invert_out : in std_ulogic;
is_signed : in std_ulogic;
result : out std_ulogic_vector(63 downto 0);
datalen : in std_logic_vector(3 downto 0)
);
@ -92,7 +93,8 @@ architecture behaviour of logical is

begin
logical_0: process(all)
variable rb_adj, tmp : std_ulogic_vector(63 downto 0);
variable rb_adj, rs_adj : std_ulogic_vector(63 downto 0);
variable tmp : std_ulogic_vector(63 downto 0);
variable negative : std_ulogic;
variable j : integer;
begin
@ -123,19 +125,34 @@ begin
end if;

case op is
when OP_AND | OP_OR | OP_XOR =>
case op is
when OP_AND =>
tmp := rs and rb_adj;
when OP_OR =>
tmp := rs or rb_adj;
when others =>
tmp := rs xor rb_adj;
end case;
when OP_LOGIC =>
-- for now, abuse the 'is_signed' field to indicate inversion of RS
rs_adj := rs;
if is_signed = '1' then
rs_adj := not rs;
end if;
tmp := rs_adj and rb_adj;
if invert_out = '1' then
tmp := not tmp;
end if;
when OP_XOR =>
tmp := rs xor rb;
if invert_out = '1' then
tmp := not tmp;
end if;

when OP_BREV =>
if datalen(3) = '1' then
tmp := rs( 7 downto 0) & rs(15 downto 8) & rs(23 downto 16) & rs(31 downto 24) &
rs(39 downto 32) & rs(47 downto 40) & rs(55 downto 48) & rs(63 downto 56);
elsif datalen(2) = '1' then
tmp := rs(39 downto 32) & rs(47 downto 40) & rs(55 downto 48) & rs(63 downto 56) &
rs( 7 downto 0) & rs(15 downto 8) & rs(23 downto 16) & rs(31 downto 24);
else
tmp := rs(55 downto 48) & rs(63 downto 56) & rs(39 downto 32) & rs(47 downto 40) &
rs(23 downto 16) & rs(31 downto 24) & rs( 7 downto 0) & rs(15 downto 8);
end if;

when OP_PRTY =>
tmp := parity;
when OP_CMPB =>

3
predecode.vhdl
Unescape Escape View File

@ -184,6 +184,9 @@ architecture behaviour of predecoder is
2#0_00000_11100# => INSN_and,
2#0_00001_11100# => INSN_andc,
2#0_00111_11100# => INSN_bperm,
2#0_00110_11011# => INSN_brh,
2#0_00100_11011# => INSN_brw,
2#0_00101_11011# => INSN_brd,
2#0_01001_11010# => INSN_cbcdtd,
2#0_01000_11010# => INSN_cdtbcd,
2#0_00000_00000# => INSN_cmp,

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