Merge pull request #62 from antonblanchard/byte-reverse-store-opt

Move byte reversal of stores to first cycle
pull/63/head
Anton Blanchard 5 years ago committed by GitHub
commit 550b2b8608
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@ -4,6 +4,7 @@ use ieee.numeric_std.all;

library work;
use work.common.all;
use work.helpers.all;

-- 2 cycle LSU
-- We calculate the address in the first cycle
@ -47,6 +48,11 @@ begin
v.update := l_in.update;
v.update_reg := l_in.update_reg;

-- byte reverse stores in the first cycle
if v.load = '0' and l_in.byte_reverse = '1' then
v.data := byte_reverse(l_in.data, to_integer(unsigned(l_in.length)));
end if;

v.addr := lsu_sum;

-- Update registers

@ -102,10 +102,6 @@ begin
m_tmp.we <= '1';

data := l_in.data;
if l_in.byte_reverse = '1' then
data := byte_reverse(data, to_integer(unsigned(l_in.length)));
end if;

m_tmp.dat <= std_logic_vector(shift_left(unsigned(data), wishbone_data_shift(l_in.addr)));

assert l_in.sign_extend = '0' report "sign extension doesn't make sense for stores" severity failure;

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