mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-21 03:29:40 +00:00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2696 91177308-0d34-0410-b5e6-96231b3b80d8
170 lines
5.7 KiB
C++
170 lines
5.7 KiB
C++
//===-- Scalar.h - Scalar Transformations ------------------------*- C++ -*-==//
|
|
//
|
|
// This header file defines prototypes for accessor functions that expose passes
|
|
// in the Scalar transformations library.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_TRANSFORMS_SCALAR_H
|
|
#define LLVM_TRANSFORMS_SCALAR_H
|
|
|
|
class Pass;
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Constant Propogation Pass - A worklist driven constant propogation pass
|
|
//
|
|
Pass *createConstantPropogationPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Sparse Conditional Constant Propogation Pass
|
|
//
|
|
Pass *createSCCPPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// DeadInstElimination - This pass quickly removes trivially dead instructions
|
|
// without modifying the CFG of the function. It is a BasicBlockPass, so it
|
|
// runs efficiently when queued next to other BasicBlockPass's.
|
|
//
|
|
Pass *createDeadInstEliminationPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// DeadCodeElimination - This pass is more powerful than DeadInstElimination,
|
|
// because it is worklist driven that can potentially revisit instructions when
|
|
// their other instructions become dead, to eliminate chains of dead
|
|
// computations.
|
|
//
|
|
Pass *createDeadCodeEliminationPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// AggressiveDCE - This pass uses the SSA based Aggressive DCE algorithm. This
|
|
// algorithm assumes instructions are dead until proven otherwise, which makes
|
|
// it more successful are removing non-obviously dead instructions.
|
|
//
|
|
Pass *createAggressiveDCEPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// DecomposeMultiDimRefs - Convert multi-dimensional references consisting of
|
|
// any combination of 2 or more array and structure indices into a sequence of
|
|
// instructions (using getelementpr and cast) so that each instruction has at
|
|
// most one index (except structure references, which need an extra leading
|
|
// index of [0]).
|
|
//
|
|
Pass *createDecomposeMultiDimRefsPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// GCSE - This pass is designed to be a very quick global transformation that
|
|
// eliminates global common subexpressions from a function. It does this by
|
|
// examining the SSA value graph of the function, instead of doing slow
|
|
// bit-vector computations.
|
|
//
|
|
Pass *createGCSEPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// InductionVariableSimplify - Transform induction variables in a program to all
|
|
// use a single cannonical induction variable per loop.
|
|
//
|
|
Pass *createIndVarSimplifyPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// InstructionCombining - Combine instructions to form fewer, simple
|
|
// instructions. This pass does not modify the CFG, and has a tendancy to
|
|
// make instructions dead, so a subsequent DCE pass is useful.
|
|
//
|
|
// This pass combines things like:
|
|
// %Y = add int 1, %X
|
|
// %Z = add int 1, %Y
|
|
// into:
|
|
// %Z = add int 2, %X
|
|
//
|
|
Pass *createInstructionCombiningPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// LICM - This pass is a simple natural loop based loop invariant code motion
|
|
// pass.
|
|
//
|
|
Pass *createLICMPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// PiNodeInsertion - This pass inserts single entry Phi nodes into basic blocks
|
|
// that are preceeded by a conditional branch, where the branch gives
|
|
// information about the operands of the condition. For example, this C code:
|
|
// if (x == 0) { ... = x + 4;
|
|
// becomes:
|
|
// if (x == 0) {
|
|
// x2 = phi(x); // Node that can hold data flow information about X
|
|
// ... = x2 + 4;
|
|
//
|
|
// Since the direction of the condition branch gives information about X itself
|
|
// (whether or not it is zero), some passes (like value numbering or ABCD) can
|
|
// use the inserted Phi/Pi nodes as a place to attach information, in this case
|
|
// saying that X has a value of 0 in this scope. The power of this analysis
|
|
// information is that "in the scope" translates to "for all uses of x2".
|
|
//
|
|
// This special form of Phi node is refered to as a Pi node, following the
|
|
// terminology defined in the "Array Bounds Checks on Demand" paper.
|
|
//
|
|
Pass *createPiNodeInsertionPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This pass is used to promote memory references to be register references. A
|
|
// simple example of the transformation performed by this pass is:
|
|
//
|
|
// FROM CODE TO CODE
|
|
// %X = alloca int, uint 1 ret int 42
|
|
// store int 42, int *%X
|
|
// %Y = load int* %X
|
|
// ret int %Y
|
|
//
|
|
Pass *createPromoteMemoryToRegister();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This pass reassociates commutative expressions in an order that is designed
|
|
// to promote better constant propogation, GCSE, LICM, PRE...
|
|
//
|
|
// For example: 4 + (x + 5) -> x + (4 + 5)
|
|
//
|
|
Pass *createReassociatePass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// CFG Simplification - Merge basic blocks, eliminate unreachable blocks,
|
|
// simplify terminator instructions, etc...
|
|
//
|
|
Pass *createCFGSimplificationPass();
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// These functions removes symbols from functions and modules.
|
|
//
|
|
Pass *createSymbolStrippingPass();
|
|
Pass *createFullSymbolStrippingPass();
|
|
|
|
#endif
|