Repository files navigation

Started from Pauladam Smith's bloghow to get started with llvm c api, then try to make it a comprehensive code guide about llvm c api

Typical cmake project, make sure LLVM in cmake search path

1. simple function --create_sum_fn: Adopted Paladam'ssum code to LLVM 14 and C++
2. call function in libc --create_out_fn: Call functions from libc,puts
3. recursive calls and TCE --create_factorial_fn: Recursive functionfactorial(n) withLLVMAddTailCallEliminationPass to eliminate recursive calls in IR
4. more complicated recursive calls and TCE --create_fib_fn: Naive recursive implementation offib(n), clearly only the lastfib call infib(n-1) + fib(n-2) got TCE optimized
5. if-the-else with PHI --create_is_odd_fn:if then else pattern
6. while-do without PHI --create_factorial_loop_fn:while-do without PHI. For factorial, this version and the recursive one optimized down to the same IR code.
7. array access with GEP --create_ap_sum_fn: Sum of an array of arithmetic progression numbers, I really hoped LLVM can do it in the way of(f + l) * n / 2, but sadly no, still loops
8. Niubi LLVM optimization --create_ap_simple_sum_fn: Sum ofan array of a sequence of arithmetic progression numbers, still not using that formula, maybe because of some optimization are missing,unlike pure -O3, maybe it is being done during re-write

Inorcv2jit.cpp file

1. Found memory leaks inllvm official example, filed abug report, fixed in4246269
2. In the same bug report, I mentionedLLVMOrcIRTransformLayerSetTransform causesmemory leaks, fixed inbc062e0
3. cal_fact_4: call to another function in a different module