brendanhaines/cpu
1
0
Fork 0
mirror of https://gitlab.com/brendanhaines/cpu.git synced 2024-12-26 02:56:52 -07:00
Code Issues Packages Projects Releases Wiki Activity

sub, and, or don't always work

Browse Source
This commit is contained in:
Brendan Haines 2020-10-03 13:49:14 -06:00
parent 18892acec9
commit 3fbd96ca27
3 changed files with 104 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
hdl/core.v
View File

@ -244,13 +244,13 @@ always @(*) begin
s_ex_alu_out = s_ex_data1 + (s_ex_data2 ^ {32{r_ex_alu_seed}}) + r_ex_alu_seed;
end
ALUOP_XOR: begin
s_ex_alu_out = (|s_ex_data1) ^ (|s_ex_data2);
s_ex_alu_out = s_ex_data1 ^ s_ex_data2;
end
ALUOP_OR: begin
s_ex_alu_out = (|s_ex_data1) | (|s_ex_data2);
s_ex_alu_out = s_ex_data1 | s_ex_data2;
end
ALUOP_AND: begin
s_ex_alu_out = (|s_ex_data1) & (|s_ex_data2);
s_ex_alu_out = s_ex_data1 & s_ex_data2;
end
ALUOP_SL: begin
s_ex_alu_out = s_ex_data1 << s_ex_data2;

2
test/Makefile
View File

@ -2,7 +2,7 @@ all: test.hex
CC = riscv64-linux-gnu-gcc
# CFLAGS = -march=rv32i -mabi=ilp32
CFLAGS = -march=rv64i -mabi=lp64
CFLAGS = -march=rv64i -mabi=lp64 -o0
AS = riscv64-linux-gnu-as
ASFLAGS = $(CFLAGS)

59
test/test.S
View File

@ -33,32 +33,75 @@ add x29, x0, x0
add x30, x0, x0
add x31, x0, x0
# nop required because cpu currently does not detect when something is needed from a later stage of the pipeline.
# 5 clocks allows one instruction to finish before the next starts
# NOTE: nop required because cpu currently does not detect when something is needed from a later stage of the pipeline.
# 4 clocks allows one instruction to finish before the next starts
# lui
nop
nop
nop
nop
nop
addi x1, x0, 0x12
lui x1, 0xfedcb # x1 = 0xfedcb000
# addi
nop
nop
nop
addi x1, x1, 0x789 # x1 = 0xfedcb789
addi x2, x0, -1 # x2 = 0xffffffff
nop
nop
addi x2, x0, 0x11
addi x3, x1, -0x777 # x3 = 0xfedcb012
# add
nop
nop
nop
add x4, x1, x2 # x4 = 0xfedcb788
# sub
nop
nop
add x3, x2, x1
nop
add x5, x1, x3 # x5 = 0x00000777 incorrect
# and
nop
nop
nop
and x6, x1, x2 # x6 = 0xfedcb789
and x7, x1, x0 # x7 = 0x00000000
and x8, x4, x3 # x8 = 0xfedcb002 incorrect
# or
nop
nop
nop
or x9, x1, x2 # x9 = 0xffffffff
or x10, x1, x0 # x10 = 0xfedcb789
or x11, x4, x3 # x11 = 0x0xfedcb798 incorrect
nop
nop
nop
addi x31, x0, 1 # x1 = 1
loop:
nop
nop
nop
addi x31, x31, 1 # increment x1
nop
nop
nop
j loop # loop forever
nop
nop
nop
nop
nop
nop
j loop
.data