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* [DDG] Data Dependence Graph - Root NodeBardia Mahjour2019-10-011-0/+28
| | | | | | | | | | | | | | | | | | | Summary: This patch adds Root Node to the DDG. The purpose of the root node is to create a single entry node that allows graph walk iterators to iterate through all nodes of the graph, making sure that no node is left unvisited during a graph walk (eg. SCC or DFS). Once the DDG is fully constructed it will have exactly one root node. Every node in the graph is reachable from the root. The algorithm for connecting the root node is based on depth-first-search that keeps track of visited nodes to try to avoid creating unnecessary edges. Authored By: bmahjour Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert Reviewed By: Meinersbur Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto, ppc-slack Tag: #llvm Differential Revision: https://reviews.llvm.org/D67970 llvm-svn: 373386
* Data Dependence Graph BasicsBardia Mahjour2019-09-181-0/+200
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This is the first patch in a series of patches that will implement data dependence graph in LLVM. Many of the ideas used in this implementation are based on the following paper: D. J. Kuck, R. H. Kuhn, D. A. Padua, B. Leasure, and M. Wolfe (1981). DEPENDENCE GRAPHS AND COMPILER OPTIMIZATIONS. This patch contains support for a basic DDGs containing only atomic nodes (one node for each instruction). The edges are two fold: def-use edges and memory-dependence edges. The implementation takes a list of basic-blocks and only considers dependencies among instructions in those basic blocks. Any dependencies coming into or going out of instructions that do not belong to those basic blocks are ignored. The algorithm for building the graph involves the following steps in order: 1. For each instruction in the range of basic blocks to consider, create an atomic node in the resulting graph. 2. For each node in the graph establish def-use edges to/from other nodes in the graph. 3. For each pair of nodes containing memory instruction(s) create memory edges between them. This part of the algorithm goes through the instructions in lexicographical order and creates edges in reverse order if the sink of the dependence occurs before the source of it. Authored By: bmahjour Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert Reviewed By: Meinersbur, fhahn, myhsu Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto Tag: #llvm Differential Revision: https://reviews.llvm.org/D65350 llvm-svn: 372238
* Revert "Data Dependence Graph Basics"Bardia Mahjour2019-09-171-200/+0
| | | | | | This reverts commit c98ec60993a7aa65073692b62f6d728b36e68ccd, which broke the sphinx-docs build. llvm-svn: 372168
* Data Dependence Graph BasicsBardia Mahjour2019-09-171-0/+200
Summary: This is the first patch in a series of patches that will implement data dependence graph in LLVM. Many of the ideas used in this implementation are based on the following paper: D. J. Kuck, R. H. Kuhn, D. A. Padua, B. Leasure, and M. Wolfe (1981). DEPENDENCE GRAPHS AND COMPILER OPTIMIZATIONS. This patch contains support for a basic DDGs containing only atomic nodes (one node for each instruction). The edges are two fold: def-use edges and memory-dependence edges. The implementation takes a list of basic-blocks and only considers dependencies among instructions in those basic blocks. Any dependencies coming into or going out of instructions that do not belong to those basic blocks are ignored. The algorithm for building the graph involves the following steps in order: 1. For each instruction in the range of basic blocks to consider, create an atomic node in the resulting graph. 2. For each node in the graph establish def-use edges to/from other nodes in the graph. 3. For each pair of nodes containing memory instruction(s) create memory edges between them. This part of the algorithm goes through the instructions in lexicographical order and creates edges in reverse order if the sink of the dependence occurs before the source of it. Authored By: bmahjour Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert Reviewed By: Meinersbur, fhahn, myhsu Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto Tag: #llvm Differential Revision: https://reviews.llvm.org/D65350 llvm-svn: 372162
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