Remove option for "short" 16x16 bit multiplier

Now that we have a 33 bit x 33 bit signed multiplier in execute1,
there is really no need for the 16 bit multiplier.  The coremark
results are just as good without it as with it.  This removes the
option for the sake of simplicity.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
pull/382/head
Paul Mackerras 2 years ago
parent e02d8060ed
commit d1e8e62fee

@ -13,7 +13,6 @@ entity core is
EX1_BYPASS : boolean := true;
HAS_FPU : boolean := true;
HAS_BTC : boolean := true;
HAS_SHORT_MULT : boolean := false;
ALT_RESET_ADDRESS : std_ulogic_vector(63 downto 0) := (others => '0');
LOG_LENGTH : natural := 512;
ICACHE_NUM_LINES : natural := 64;
@ -366,7 +365,6 @@ begin
SIM => SIM,
EX1_BYPASS => EX1_BYPASS,
HAS_FPU => HAS_FPU,
HAS_SHORT_MULT => HAS_SHORT_MULT,
LOG_LENGTH => LOG_LENGTH
)
port map (

@ -15,7 +15,6 @@ entity execute1 is
SIM : boolean := false;
EX1_BYPASS : boolean := true;
HAS_FPU : boolean := true;
HAS_SHORT_MULT : boolean := false;
-- Non-zero to enable log data collection
LOG_LENGTH : natural := 0
);
@ -448,17 +447,6 @@ begin
p_out => pmu_to_x
);

short_mult_0: if HAS_SHORT_MULT generate
begin
short_mult: entity work.short_multiply
port map (
clk => clk,
a_in => a_in(15 downto 0),
b_in => b_in(15 downto 0),
m_out => mshort_p
);
end generate;

dbg_ctrl_out <= ctrl;
log_rd_addr <= ex2.log_addr_spr;

@ -1288,13 +1276,6 @@ begin
v.se.mult_32s := '1';
v.res2_sel := "00";
slow_op := '1';
elsif HAS_SHORT_MULT and e_in.reg_valid3 = '0' and
fits_in_n_bits(a_in, 16) and fits_in_n_bits(b_in, 16) then
-- Operands fit into 16 bits, so use short multiplier
if e_in.oe = '1' then
-- Note 16x16 multiply can't overflow, even for mullwo
set_ov(v.e, '0', '0');
end if;
else
-- Use standard multiplier
v.start_mul := '1';

@ -16,7 +16,6 @@ entity toplevel is
CLK_FREQUENCY : positive := 100000000;
HAS_FPU : boolean := true;
HAS_BTC : boolean := true;
HAS_SHORT_MULT : boolean := false;
USE_LITEDRAM : boolean := false;
NO_BRAM : boolean := false;
DISABLE_FLATTEN_CORE : boolean := false;
@ -199,7 +198,6 @@ begin
CLK_FREQ => CLK_FREQUENCY,
HAS_FPU => HAS_FPU,
HAS_BTC => HAS_BTC,
HAS_SHORT_MULT => HAS_SHORT_MULT,
HAS_DRAM => USE_LITEDRAM,
DRAM_SIZE => 256 * 1024 * 1024,
DRAM_INIT_SIZE => PAYLOAD_SIZE,

@ -13,7 +13,6 @@ entity toplevel is
CLK_FREQUENCY : positive := 100000000;
HAS_FPU : boolean := true;
HAS_BTC : boolean := false;
HAS_SHORT_MULT: boolean := false;
ICACHE_NUM_LINES : natural := 64;
LOG_LENGTH : natural := 512;
DISABLE_FLATTEN_CORE : boolean := false;
@ -75,7 +74,6 @@ begin
CLK_FREQ => CLK_FREQUENCY,
HAS_FPU => HAS_FPU,
HAS_BTC => HAS_BTC,
HAS_SHORT_MULT => HAS_SHORT_MULT,
ICACHE_NUM_LINES => ICACHE_NUM_LINES,
LOG_LENGTH => LOG_LENGTH,
DISABLE_FLATTEN_CORE => DISABLE_FLATTEN_CORE,

@ -16,7 +16,6 @@ entity toplevel is
CLK_FREQUENCY : positive := 100000000;
HAS_FPU : boolean := true;
HAS_BTC : boolean := true;
HAS_SHORT_MULT: boolean := false;
USE_LITEDRAM : boolean := false;
NO_BRAM : boolean := false;
DISABLE_FLATTEN_CORE : boolean := false;
@ -175,7 +174,6 @@ begin
CLK_FREQ => CLK_FREQUENCY,
HAS_FPU => HAS_FPU,
HAS_BTC => HAS_BTC,
HAS_SHORT_MULT=> HAS_SHORT_MULT,
HAS_DRAM => USE_LITEDRAM,
DRAM_SIZE => 512 * 1024 * 1024,
DRAM_INIT_SIZE => PAYLOAD_SIZE,

@ -188,7 +188,6 @@ begin
HAS_UART1 => HAS_UART1,
HAS_SD_CARD => USE_LITESDCARD,
ICACHE_NUM_LINES => ICACHE_NUM_LINES,
HAS_SHORT_MULT => true,
NGPIO => NGPIO
)
port map (

@ -16,7 +16,6 @@ entity toplevel is
CLK_FREQUENCY : positive := 100000000;
HAS_FPU : boolean := true;
HAS_BTC : boolean := true;
HAS_SHORT_MULT : boolean := false;
USE_LITEDRAM : boolean := false;
NO_BRAM : boolean := false;
DISABLE_FLATTEN_CORE : boolean := false;
@ -175,7 +174,6 @@ begin
CLK_FREQ => CLK_FREQUENCY,
HAS_FPU => HAS_FPU,
HAS_BTC => HAS_BTC,
HAS_SHORT_MULT => HAS_SHORT_MULT,
HAS_DRAM => USE_LITEDRAM,
DRAM_SIZE => 256 * 1024 * 1024,
DRAM_INIT_SIZE => PAYLOAD_SIZE,

@ -146,7 +146,6 @@ targets:
- uart_is_16550
- has_fpu
- has_btc
- has_short_mult
tools:
vivado: {part : xc7a100tcsg324-1}
toplevel : toplevel
@ -252,7 +251,6 @@ targets:
- uart_is_16550
- has_fpu
- has_btc
- has_short_mult
generate: [litedram_nexys_video, liteeth_nexys_video, litesdcard_nexys_video]
tools:
vivado: {part : xc7a200tsbg484-1}
@ -273,7 +271,6 @@ targets:
- has_uart1
- has_fpu=false
- has_btc=false
- has_short_mult
- use_litesdcard
tools:
vivado: {part : xc7a35ticsg324-1L}
@ -296,7 +293,6 @@ targets:
- has_uart1
- has_fpu=false
- has_btc=false
- has_short_mult
generate: [litedram_arty, liteeth_arty, litesdcard_arty]
tools:
vivado: {part : xc7a35ticsg324-1L}
@ -317,7 +313,6 @@ targets:
- has_uart1
- has_fpu
- has_btc
- has_short_mult
- use_litesdcard
tools:
vivado: {part : xc7a100ticsg324-1L}
@ -340,7 +335,6 @@ targets:
- has_uart1
- has_fpu
- has_btc
- has_short_mult
generate: [litedram_arty, liteeth_arty, litesdcard_arty]
tools:
vivado: {part : xc7a100ticsg324-1L}
@ -362,7 +356,6 @@ targets:
- uart_is_16550
- has_fpu
- has_btc
- has_short_mult
generate: [litesdcard_wukong-v2]
tools:
vivado: {part : xc7a100tfgg676-1}
@ -384,7 +377,6 @@ targets:
- uart_is_16550
- has_fpu
- has_btc
- has_short_mult
generate: [litedram_wukong-v2, liteeth_wukong-v2, litesdcard_wukong-v2]
tools:
vivado: {part : xc7a100tfgg676-1}
@ -500,12 +492,6 @@ parameters:
paramtype : generic
default : true

has_short_mult:
datatype : bool
description : Include a 16 bit x 16 bit single-cycle multiplier in the core
paramtype : generic
default : false

disable_flatten_core:
datatype : bool
description : Prevent Vivado from flattening the main core components

@ -59,7 +59,6 @@ entity soc is
SIM : boolean;
HAS_FPU : boolean := true;
HAS_BTC : boolean := true;
HAS_SHORT_MULT : boolean := false;
DISABLE_FLATTEN_CORE : boolean := false;
ALT_RESET_ADDRESS : std_logic_vector(63 downto 0) := (23 downto 0 => '0', others => '1');
HAS_DRAM : boolean := false;
@ -335,7 +334,6 @@ begin
SIM => SIM,
HAS_FPU => HAS_FPU,
HAS_BTC => HAS_BTC,
HAS_SHORT_MULT => HAS_SHORT_MULT,
DISABLE_FLATTEN => DISABLE_FLATTEN_CORE,
ALT_RESET_ADDRESS => ALT_RESET_ADDRESS,
LOG_LENGTH => LOG_LENGTH,

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