Data hazard prevention

Implement a Fibonacci series computation algorithm for pipelined processors without a hazard unit.

Program will load the length of the Fibonacci series from fibo_limit, and should save it into an array of 32-bit integer words starting at the address fibo_series.

The complete task description can also be found here, Makefile and template files for your own testing can be found on GitLab.

Makefile (click) 

						ARCH=riscv64-unknown-elf

SOURCES = submission.S
TARGET_EXE = submission

CC=$(ARCH)-gcc
CXX=$(ARCH)-g++
AS=$(ARCH)-as
LD=$(ARCH)-ld
OBJCOPY=$(ARCH)-objcopy

ARCHFLAGS += -mabi=ilp32
ARCHFLAGS += -march=rv32i
ARCHFLAGS += -fno-lto

CFLAGS  += -ggdb -Os -Wall
CXXFLAGS+= -ggdb -Os -Wall
AFLAGS  += -ggdb
LDFLAGS += -ggdb
LDFLAGS += -nostartfiles
LDFLAGS += -nostdlib
LDFLAGS += -static
#LDFLAGS += -specs=/opt/musl/riscv64-linux-gnu/lib/musl-gcc.specs

CFLAGS  += $(ARCHFLAGS)
CXXFLAGS+= $(ARCHFLAGS)
AFLAGS  += $(ARCHFLAGS)
LDFLAGS += $(ARCHFLAGS)

OBJECTS += $(filter %.o,$(SOURCES:%.S=%.o))
OBJECTS += $(filter %.o,$(SOURCES:%.c=%.o))
OBJECTS += $(filter %.o,$(SOURCES:%.cpp=%.o))

all : default

.PHONY : default clean dep all run_test

%.o:%.S
	$(CC) -D__ASSEMBLY__ $(AFLAGS) -c $< -o $@

%.o:%.c
	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@

%.o:%.cpp
	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $<

%.s:%.c
	$(CC) $(CFLAGS) $(CPPFLAGS) -S $< -o $@

default : submission

$(TARGET_EXE) : $(OBJECTS)
	$(CC) $(LDFLAGS) $^ -o $@

dep: depend

depend: $(SOURCES) $(glob *.h)
	echo '# autogenerated dependencies' > depend
ifneq ($(filter %.S,$(SOURCES)),)
	$(CC)  -D__ASSEMBLY__ $(AFLAGS) -w -E -M $(filter %.S,$(SOURCES)) >> depend
endif
ifneq ($(filter %.c,$(SOURCES)),)
	$(CC) $(CFLAGS) $(CPPFLAGS) -w -E -M $(filter %.c,$(SOURCES)) >> depend
endif
ifneq ($(filter %.cpp,$(SOURCES)),)
	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -w -E -M $(filter %.cpp,$(SOURCES)) >> depend
endif

clean:
	rm -f *.o *.a $(OBJECTS) $(TARGET_EXE) depend

-include depend
Input: Data hazard prevention.
In: Size of the array located at address fibo_limit.
Out: Array of Fibonacci numbers starting at the address fibo_series.

Your program will be run with the following arguments: --dump-cycles --pipelined --hazard-unit none --cycle-limit 5000 --asm submission.S
Your program will be scored by this following metric: Runtime of the program in cycles.

For interactive solution, you can use QtRvSim. The web version of the simulator is located here.
Top Scores (cycles)
  • svehlda2
    90
  • reference
    979