llvm-project/llvm/include/llvm-c/Transforms/Scalar.h

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/*===-- Scalar.h - Scalar Transformation Library C Interface ----*- C++ -*-===*\
|* *|
|* The LLVM Compiler Infrastructure *|
|* *|
|* This file is distributed under the University of Illinois Open Source *|
|* License. See LICENSE.TXT for details. *|
|* *|
|*===----------------------------------------------------------------------===*|
|* *|
|* This header declares the C interface to libLLVMScalarOpts.a, which *|
|* implements various scalar transformations of the LLVM IR. *|
|* *|
|* Many exotic languages can interoperate with C code but have a harder time *|
|* with C++ due to name mangling. So in addition to C, this interface enables *|
|* tools written in such languages. *|
|* *|
\*===----------------------------------------------------------------------===*/
#ifndef LLVM_C_TRANSFORMS_SCALAR_H
#define LLVM_C_TRANSFORMS_SCALAR_H
#include "llvm-c/Core.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup LLVMCTransformsScalar Scalar transformations
* @ingroup LLVMCTransforms
*
* @{
*/
/** See llvm::createAggressiveDCEPass function. */
void LLVMAddAggressiveDCEPass(LLVMPassManagerRef PM);
/** See llvm::createCFGSimplificationPass function. */
void LLVMAddCFGSimplificationPass(LLVMPassManagerRef PM);
/** See llvm::createDeadStoreEliminationPass function. */
void LLVMAddDeadStoreEliminationPass(LLVMPassManagerRef PM);
/** See llvm::createGVNPass function. */
void LLVMAddGVNPass(LLVMPassManagerRef PM);
/** See llvm::createIndVarSimplifyPass function. */
void LLVMAddIndVarSimplifyPass(LLVMPassManagerRef PM);
/** See llvm::createInstructionCombiningPass function. */
void LLVMAddInstructionCombiningPass(LLVMPassManagerRef PM);
/** See llvm::createJumpThreadingPass function. */
void LLVMAddJumpThreadingPass(LLVMPassManagerRef PM);
/** See llvm::createLICMPass function. */
void LLVMAddLICMPass(LLVMPassManagerRef PM);
/** See llvm::createLoopDeletionPass function. */
void LLVMAddLoopDeletionPass(LLVMPassManagerRef PM);
/** See llvm::createLoopIdiomPass function */
void LLVMAddLoopIdiomPass(LLVMPassManagerRef PM);
/** See llvm::createLoopRotatePass function. */
void LLVMAddLoopRotatePass(LLVMPassManagerRef PM);
Add a loop rerolling pass This adds a loop rerolling pass: the opposite of (partial) loop unrolling. The transformation aims to take loops like this: for (int i = 0; i < 3200; i += 5) { a[i] += alpha * b[i]; a[i + 1] += alpha * b[i + 1]; a[i + 2] += alpha * b[i + 2]; a[i + 3] += alpha * b[i + 3]; a[i + 4] += alpha * b[i + 4]; } and turn them into this: for (int i = 0; i < 3200; ++i) { a[i] += alpha * b[i]; } and loops like this: for (int i = 0; i < 500; ++i) { x[3*i] = foo(0); x[3*i+1] = foo(0); x[3*i+2] = foo(0); } and turn them into this: for (int i = 0; i < 1500; ++i) { x[i] = foo(0); } There are two motivations for this transformation: 1. Code-size reduction (especially relevant, obviously, when compiling for code size). 2. Providing greater choice to the loop vectorizer (and generic unroller) to choose the unrolling factor (and a better ability to vectorize). The loop vectorizer can take vector lengths and register pressure into account when choosing an unrolling factor, for example, and a pre-unrolled loop limits that choice. This is especially problematic if the manual unrolling was optimized for a machine different from the current target. The current implementation is limited to single basic-block loops only. The rerolling recognition should work regardless of how the loop iterations are intermixed within the loop body (subject to dependency and side-effect constraints), but the significant restriction is that the order of the instructions in each iteration must be identical. This seems sufficient to capture all current use cases. This pass is not currently enabled by default at any optimization level. llvm-svn: 194939
2013-11-17 07:59:05 +08:00
/** See llvm::createLoopRerollPass function. */
void LLVMAddLoopRerollPass(LLVMPassManagerRef PM);
/** See llvm::createLoopUnrollPass function. */
void LLVMAddLoopUnrollPass(LLVMPassManagerRef PM);
/** See llvm::createLoopUnswitchPass function. */
void LLVMAddLoopUnswitchPass(LLVMPassManagerRef PM);
/** See llvm::createMemCpyOptPass function. */
void LLVMAddMemCpyOptPass(LLVMPassManagerRef PM);
/** See llvm::createPartiallyInlineLibCallsPass function. */
void LLVMAddPartiallyInlineLibCallsPass(LLVMPassManagerRef PM);
/** See llvm::createPromoteMemoryToRegisterPass function. */
void LLVMAddPromoteMemoryToRegisterPass(LLVMPassManagerRef PM);
/** See llvm::createReassociatePass function. */
void LLVMAddReassociatePass(LLVMPassManagerRef PM);
/** See llvm::createSCCPPass function. */
void LLVMAddSCCPPass(LLVMPassManagerRef PM);
/** See llvm::createScalarReplAggregatesPass function. */
void LLVMAddScalarReplAggregatesPass(LLVMPassManagerRef PM);
/** See llvm::createScalarReplAggregatesPass function. */
void LLVMAddScalarReplAggregatesPassSSA(LLVMPassManagerRef PM);
/** See llvm::createScalarReplAggregatesPass function. */
void LLVMAddScalarReplAggregatesPassWithThreshold(LLVMPassManagerRef PM,
int Threshold);
/** See llvm::createSimplifyLibCallsPass function. */
void LLVMAddSimplifyLibCallsPass(LLVMPassManagerRef PM);
/** See llvm::createTailCallEliminationPass function. */
void LLVMAddTailCallEliminationPass(LLVMPassManagerRef PM);
/** See llvm::createConstantPropagationPass function. */
void LLVMAddConstantPropagationPass(LLVMPassManagerRef PM);
/** See llvm::demotePromoteMemoryToRegisterPass function. */
void LLVMAddDemoteMemoryToRegisterPass(LLVMPassManagerRef PM);
/** See llvm::createVerifierPass function. */
void LLVMAddVerifierPass(LLVMPassManagerRef PM);
/** See llvm::createCorrelatedValuePropagationPass function */
void LLVMAddCorrelatedValuePropagationPass(LLVMPassManagerRef PM);
/** See llvm::createEarlyCSEPass function */
void LLVMAddEarlyCSEPass(LLVMPassManagerRef PM);
/** See llvm::createLowerExpectIntrinsicPass function */
void LLVMAddLowerExpectIntrinsicPass(LLVMPassManagerRef PM);
/** See llvm::createTypeBasedAliasAnalysisPass function */
void LLVMAddTypeBasedAliasAnalysisPass(LLVMPassManagerRef PM);
/** See llvm::createBasicAliasAnalysisPass function */
void LLVMAddBasicAliasAnalysisPass(LLVMPassManagerRef PM);
/**
* @}
*/
#ifdef __cplusplus
}
#endif /* defined(__cplusplus) */
#endif