Is LLVM free software?
Yes to everyone else in the world, including the FSF, Clang/LLVM is free software but according to RMS it is not. You’re confounding issues here.
What is a type of instruction scheduling?
There are several types of instruction scheduling: Local (basic block) scheduling: instructions can’t move across basic block boundaries. Global scheduling: instructions can move across basic block boundaries.
What is an LLVM backend?
The backend of LLVM features a target-independent code generator that may create output for several types of target CPUs — including X86, PowerPC, ARM, and SPARC. The backend may also be used to generate code targeted at SPUs of the Cell processor or GPUs to support the execution of compute kernels.
Who owns LLVM?
LLVM
| The LLVM logo, a stylized wyvern | |
|---|---|
| Original author(s) | Vikram Adve, Chris Lattner |
| Developer(s) | LLVM Developer Group |
| Initial release | 2003 |
| Stable release | 13.0.0 / September 30, 2021 |
Is LLVM a runtime?
The GraalVM LLVM runtime can execute programming languages that can be transformed to LLVM bitcode. This includes languages like C/C++, Fortran and others.
What is static instruction scheduling?
Static Scheduling-In-order execution: Fetch, decode and execute steps of instructions and operand fetch and store steps are overlapped or pipelined in the order they are written in the program.
What is code scheduling?
Code scheduling is a form of program optimization that applies to the machine code that is produced by the code generator. The schedule must not oversubscribe the resources on the machine. These scheduling constraints guarantee that the optimized program pro-duces the same results as the original.
Who uses LLVM?
Apple’s Swift language uses LLVM as its compiler framework, and Rust uses LLVM as a core component of its tool chain. Also, many compilers have an LLVM edition, such as Clang, the C/C++ compiler (this the name, “C-lang”), itself a project closely allied with LLVM.
Where does the instruction scheduler run in LLVM?
As is noted in Getting Started with LLVM Core Librariesthere are three distinct instruction schedulers in the LLVM backend. One of them runs before register allocation and it can be selected using the -pre-RA-schedoption. The other two run after register allocation.
How is static instruction scheduling used in VLIW?
1 Static Instruction Scheduling (Compile Time) − Ordering of instruction stream to minimize stalls and increase IPC − Critical for VLIW, still really important for simple in-order and out-of-order superscaler machines Dynamic Instruction Scheduling (On Device) − Selectively issuing instructions out-of-order to minimize stalls and increase IPC
What can the backend of LLVM be used for?
The backend of LLVM features a target-independent code generator that may create output for several types of target CPUs — including X86, PowerPC, ARM, and SPARC. The backend may also be used to generate code targeted at SPUs of the Cell processor or GPUs to support the execution of compute kernels.
How to get LLVM to build and link a target?
To get LLVM to actually build and link your target, you need to run cmake with -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=Dummy. This will build your target without needing to add it to the list of all the targets.