Hi Team,
I tried to generate a code coverage report for my DPC++ code using llvm, but it is not displaying the correct result, even if each line of code is running.
Following some debugging, I discovered that it is not covering specific code under parallel for.
Sample code:-
main.cpp
#include <CL/sycl.hpp>
#include <iostream>
using namespace std;
using namespace sycl;
const std::string secret {
"Ifmmp-!xpsme\"\012J(n!tpssz-!Ebwf/!"
"J(n!bgsbje!J!dbo(u!ep!uibu/!.!IBM\01"};
const auto sz = secret.size();
int main() {
queue Q;
char*result = malloc_shared<char>(sz, Q);
std::memcpy(result,secret.data(),sz);
Q.parallel_for(sz,[=](auto&i) {
// Temp/extra code start(This is added to increase code inside parallel_for)
result[i] -= 1;
result[i] += 1;
result[i] -= 1;
result[i] += 1;
result[i] -= 1;
result[i] += 1;
// Temp/extra code end..
result[i] -= 1;
});
Q.wait();
std::cout << result << "\n";
return 0;
}
makefile
CC = dpcpp
CFLAG = -fprofile-instr-generate -fcoverage-mapping
RM = rm -rf
export LLVM__ROOT = /opt/intel/oneapi/compiler/2022.1.0/linux/bin-llvm
help: ## Makefile help
@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}' $(MAKEFILE_LIST)
main.o: main.cpp
$(CC) $(CFLAG) -c -Wall main.cpp
build: main.o ## Make build
$(CC) $(CFLAG) -o main main.o
coverage: ## Run code coverage
LLVM_PROFILE_FILE="main.profraw" ./main
$(LLVM__ROOT)/llvm-profdata merge -sparse main.profraw -o main.profdata
$(LLVM__ROOT)/llvm-cov report ./main -instr-profile=main.profdata
clean: ## Clean all generate files
$(RM) main *.o *.profdata *.profraw
Steps to generate code coverage,
$ make build
$ ./main
$ make coverageCode coverage report :-
Filename Regions Missed Regions Cover Functions Missed Functions Executed Lines Missed Lines Cover Branches Missed Branches Cover
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
main-0fb086.cpp 2 1 50.00% 2 1 50.00% 26 9 65.38% 0 0 -
main-header-16a1df.h 8 4 50.00% 8 4 50.00% 12 6 50.00% 0 0 -
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL 10 5 50.00% 10 5 50.00% 38 15 60.53% 0 0 -
Could anyone help with identifying the problem and solution, please?
Link Copied
Hi Varsha
However, even if I add more lines of code inside a particular parallel_for, the percentage of code coverage will still decrease.
Please check the attached screenshots:-
1 line of code inside parallel_for :-
- covers :- 80% of code.
7 lines of code inside parallel_for :-
- covers :- 66.67% of code.
13 lines of code inside parallel_for :-
- covers :- 61.54% of code.
As a result of this discovery, I have a suspicion that it is not covering a certain parallel_for area of the code.
Thanks & Regards,
Paavan
