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path: root/lib/CodeGen/MachineTraceMetrics.cpp
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* Machine Model: Add MicroOpBufferSize and resource BufferSize.Andrew Trick2013-06-15
| | | | | | | | | | | | | Replace the ill-defined MinLatency and ILPWindow properties with with straightforward buffer sizes: MCSchedMode::MicroOpBufferSize MCProcResourceDesc::BufferSize These can be used to more precisely model instruction execution if desired. Disabled some misched tests temporarily. They'll be reenabled in a few commits. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184032 91177308-0d34-0410-b5e6-96231b3b80d8
* Generalize the MachineTraceMetrics public API.Andrew Trick2013-04-27
| | | | | | | Naturally, we should be able to pass in extra instructions, not just extra blocks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180667 91177308-0d34-0410-b5e6-96231b3b80d8
* Allow MachineTraceMetrics to be used when the model has no resources.Jakob Stoklund Olesen2013-04-02
| | | | | | | It it still possible to extract information from itineraries, for example. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178582 91177308-0d34-0410-b5e6-96231b3b80d8
* Count processor resources individually in MachineTraceMetrics.Jakob Stoklund Olesen2013-04-02
| | | | | | | | | | | | | | | The new instruction scheduling models provide information about the number of cycles consumed on each processor resource. This makes it possible to estimate ILP more accurately than simply counting instructions / issue width. The functions getResourceDepth() and getResourceLength() now identify the limiting processor resource, and return a cycle count based on that. This gives more precise resource information, particularly in traces that use one resource a lot more than others. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178553 91177308-0d34-0410-b5e6-96231b3b80d8
* Rename isEarlierInSameTrace to isUsefulDominator.Jakob Stoklund Olesen2013-03-07
| | | | | | | | | | | | | | In very rare cases caused by irreducible control flow, the dominating block can have the same trace head without actually being part of the trace. As long as such a dominator still has valid instruction depths, it is OK to use it for computing instruction depths. Rename the function to avoid lying, and add a check that instruction depths are computed for the dominator. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176668 91177308-0d34-0410-b5e6-96231b3b80d8
* Move MachineTraceMetrics.h into include/llvm/CodeGen.Jakob Stoklund Olesen2013-01-17
| | | | | | Let targets use it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172688 91177308-0d34-0410-b5e6-96231b3b80d8
* Use the new script to sort the includes of every file under lib.Chandler Carruth2012-12-03
| | | | | | | | | | | | | | | | | Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
* Pass an explicit operand number to addLiveIns.Jakob Stoklund Olesen2012-10-11
| | | | | | | | | Not all instructions define a virtual register in their first operand. Specifically, INLINEASM has a different format. <rdar://problem/12472811> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165721 91177308-0d34-0410-b5e6-96231b3b80d8
* Don't crash on extra evil irreducible control flow.Jakob Stoklund Olesen2012-10-08
| | | | | | | | | | | | | | When the CFG contains a loop with multiple entry blocks, the traces computed by MachineTraceMetrics don't always have the same nice properties. Loop back-edges are normally excluded from traces, but MachineLoopInfo doesn't recognize loops with multiple entry blocks, so those back-edges may be included. Avoid asserting when that happens by adding an isEarlierInSameTrace() function that accurately determines if a dominating block is part of the same trace AND is above the currrent block in the trace. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165434 91177308-0d34-0410-b5e6-96231b3b80d8
* Switch MachineTraceMetrics to the new TargetSchedModel interface.Jakob Stoklund Olesen2012-10-04
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165235 91177308-0d34-0410-b5e6-96231b3b80d8
* Give MachineTraceMetrics its own debug tag.Jakob Stoklund Olesen2012-08-10
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161712 91177308-0d34-0410-b5e6-96231b3b80d8
* Add more trace query functions.Jakob Stoklund Olesen2012-08-10
| | | | | | | | | | | Trace::getResourceLength() computes the number of cycles required to execute the trace when ignoring data dependencies. The number can be compared to the critical path to estimate the trace ILP. Trace::getPHIDepth() computes the data dependency depth of a PHI in a trace successor that isn't necessarily part of the trace. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161711 91177308-0d34-0410-b5e6-96231b3b80d8
* Include loop-carried dependencies when computing instr heights.Jakob Stoklund Olesen2012-08-10
| | | | | | | | | When a trace ends with a back-edge, include PHIs in the loop header in the height computations. This makes the critical path through a loop more accurate by including the latencies of the last instructions in the loop. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161688 91177308-0d34-0410-b5e6-96231b3b80d8
* Deal with irreducible control flow when building traces.Jakob Stoklund Olesen2012-08-08
| | | | | | | | | | | We filter out MachineLoop back-edges during the trace-building PO traversals, but it is possible to have CFG cycles that aren't natural loops, and MachineLoopInfo doesn't include such cycles. Use a standard visited set to detect such CFG cycles, and completely ignore them when picking traces. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161532 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix a couple of typos.Jakob Stoklund Olesen2012-08-07
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161437 91177308-0d34-0410-b5e6-96231b3b80d8
* Add trace accessor methods, implement primitive if-conversion heuristic.Jakob Stoklund Olesen2012-08-07
| | | | | | | | Compare the critical paths of the two traces through an if-conversion candidate. If the difference is larger than the branch brediction penalty, reject the if-conversion. If would never pay. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161433 91177308-0d34-0410-b5e6-96231b3b80d8
* Compute the critical path length through a trace.Jakob Stoklund Olesen2012-08-02
| | | | | | | | | | | Whenever both instruction depths and instruction heights are known in a block, it is possible to compute the length of the critical path as max(depth+height) over the instructions in the block. The stored live-in lists make it possible to accurately compute the length of a critical path that bypasses the current (small) block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161197 91177308-0d34-0410-b5e6-96231b3b80d8
* Compute instruction heights through a trace.Jakob Stoklund Olesen2012-08-01
| | | | | | | | | | | | | | | | | | | The height on an instruction is the minimum number of cycles from the instruction is issued to the end of the trace. Heights are computed for all instructions in and below the trace center block. The method for computing heights is different from the depth computation. As we visit instructions in the trace bottom-up, heights of used instructions are pushed upwards. This way, we avoid scanning long use lists, looking for uses in the current trace. At each basic block boundary, a list of live-in registers and their minimum heights is saved in the trace block info. These live-in lists are used when restarting depth computations on a trace that converges with an already computed trace. They will also be used to accurately compute the critical path length. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161138 91177308-0d34-0410-b5e6-96231b3b80d8
* Add DataDep constructors. Explicitly check SSA form.Jakob Stoklund Olesen2012-08-01
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161115 91177308-0d34-0410-b5e6-96231b3b80d8
* Compute instruction depths through the current trace.Jakob Stoklund Olesen2012-07-31
| | | | | | | | | | | Assuming infinite issue width, compute the earliest each instruction in the trace can issue, when considering the latency of data dependencies. The issue cycle is record as a 'depth' from the beginning of the trace. This is half the computation required to find the length of the critical path through the trace. Heights are next. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161074 91177308-0d34-0410-b5e6-96231b3b80d8
* Rename CT -> MTM. MachineTraceMetrics is abbreviated MTM.Jakob Stoklund Olesen2012-07-31
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161072 91177308-0d34-0410-b5e6-96231b3b80d8
* Avoid looking at stale data in verifyAnalysis().Jakob Stoklund Olesen2012-07-30
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161004 91177308-0d34-0410-b5e6-96231b3b80d8
* Allow traces to enter nested loops.Jakob Stoklund Olesen2012-07-30
| | | | | | | | | | | This lets traces include the final iteration of a nested loop above the center block, and the first iteration of a nested loop below the center block. We still don't allow traces to contain backedges, and traces are truncated where they would leave a loop, as seen from the center block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161003 91177308-0d34-0410-b5e6-96231b3b80d8
* Assert that all trace candidate blocks have been visited by the PO.Jakob Stoklund Olesen2012-07-30
| | | | | | | | | | When computing a trace, all the candidates for pred/succ must have been visited. Filter out back-edges first, though. The PO traversal ignores them. Thanks to Andy for spotting this in review. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160995 91177308-0d34-0410-b5e6-96231b3b80d8
* Hook into PassManager's analysis verification.Jakob Stoklund Olesen2012-07-30
| | | | | | | By overriding Pass::verifyAnalysis(), the pass contents will be verified by the pass manager. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160994 91177308-0d34-0410-b5e6-96231b3b80d8
* Add MachineInstr::isTransient().Jakob Stoklund Olesen2012-07-30
| | | | | | | | | | | This is a cleaned up version of the isFree() function in MachineTraceMetrics.cpp. Transient instructions are very unlikely to produce any code in the final output. Either because they get eliminated by RegisterCoalescing, or because they are pseudo-instructions like labels and debug values. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160977 91177308-0d34-0410-b5e6-96231b3b80d8
* Add MachineTraceMetrics::verify().Jakob Stoklund Olesen2012-07-30
| | | | | | | This function verifies the consistency of cached data in the MachineTraceMetrics analysis. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160976 91177308-0d34-0410-b5e6-96231b3b80d8
* Verify that the CFG hasn't changed during invalidate().Jakob Stoklund Olesen2012-07-30
| | | | | | | The MachineTraceMetrics analysis must be invalidated before modifying the CFG. This will catch some of the violations of that rule. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160969 91177308-0d34-0410-b5e6-96231b3b80d8
* Add more debug output to MachineTraceMetrics.Jakob Stoklund Olesen2012-07-27
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160905 91177308-0d34-0410-b5e6-96231b3b80d8
* Keep track of the head and tail of the trace through each block.Jakob Stoklund Olesen2012-07-27
| | | | | | | This makes it possible to quickly detect blocks that are outside the trace. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160904 91177308-0d34-0410-b5e6-96231b3b80d8
* Use an otherwise unused variable.Jakob Stoklund Olesen2012-07-26
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160798 91177308-0d34-0410-b5e6-96231b3b80d8
* Start scaffolding for a MachineTraceMetrics analysis pass.Jakob Stoklund Olesen2012-07-26
This is still a work in progress. Out-of-order CPUs usually execute instructions from multiple basic blocks simultaneously, so it is necessary to look at longer traces when estimating the performance effects of code transformations. The MachineTraceMetrics analysis will pick a typical trace through a given basic block and provide performance metrics for the trace. Metrics will include: - Instruction count through the trace. - Issue count per functional unit. - Critical path length, and per-instruction 'slack'. These metrics can be used to determine the performance limiting factor when executing the trace, and how it will be affected by a code transformation. Initially, this will be used by the early if-conversion pass. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160796 91177308-0d34-0410-b5e6-96231b3b80d8
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