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path: root/lib/CodeGen/PeepholeOptimizer.cpp
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* [Peephole] Rewrite copies to avoid cross register banks copies.Quentin Colombet2013-09-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By definition copies across register banks are not coalescable. Still, it may be possible to get rid of such a copy when the value is available in another register of the same register file. Consider the following example, where capital and lower letters denote different register file: b = copy A <-- cross-bank copy ... C = copy b <-- cross-bank copy This could have been optimized this way: b = copy A <-- cross-bank copy ... C = copy A <-- same-bank copy Note: b and C's definitions may be in different basic blocks. This patch adds a peephole optimization that looks through a chain of copies leading to a cross-bank copy and reuses a source that is on the same register file if available. This solution could also be used to get rid of some copies (e.g., A could have been used instead of C). However, we do not do so because: - It may over constrain the coloring of the source register for coalescing. - The register allocator may not be able to find a nice split point for the longer live-range, leading to more spill. <rdar://problem/14742333> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190713 91177308-0d34-0410-b5e6-96231b3b80d8
* Add debug prints for when optimizeLoadInstr folds a load.Craig Topper2012-12-17
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170298 91177308-0d34-0410-b5e6-96231b3b80d8
* Add comment for load foldingJoel Jones2012-12-11
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169880 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
* Make sure we iterate over newly created instructions. Fixes pr13625. Testcase toRafael Espindola2012-10-15
| | | | | | follow in one sec. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165951 91177308-0d34-0410-b5e6-96231b3b80d8
* Use standard pattern for iterate+erase.Jakob Stoklund Olesen2012-08-17
| | | | | | | | | Increment the MBB iterator at the top of the loop to properly handle the current (and previous) instructions getting erased. This fixes PR13625. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162099 91177308-0d34-0410-b5e6-96231b3b80d8
* Add an MCID::Select flag and TII hooks for optimizing selects.Jakob Stoklund Olesen2012-08-16
| | | | | | | | | | | | Select instructions pick one of two virtual registers based on a condition, like x86 cmov. On targets like ARM that support predication, selects can sometimes be eliminated by predicating the instruction defining one of the operands. Teach PeepholeOptimizer to recognize select instructions, and ask the target to optimize them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162059 91177308-0d34-0410-b5e6-96231b3b80d8
* X86 Peephole: fold loads to the source register operand if possible.Manman Ren2012-08-02
| | | | | | | | | | | Add more comments and use early returns to reduce nesting in isLoadFoldable. Also disable folding for V_SET0 to avoid introducing a const pool entry and a const pool load. rdar://10554090 and rdar://11873276 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161207 91177308-0d34-0410-b5e6-96231b3b80d8
* X86 Peephole: fold loads to the source register operand if possible.Manman Ren2012-08-02
| | | | | | | | | | | | | Machine CSE and other optimizations can remove instructions so folding is possible at peephole while not possible at ISel. This patch is a rework of r160919 and was tested on clang self-host on my local machine. rdar://10554090 and rdar://11873276 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161152 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r160920 and r160919 due to dragonegg and clang selfhost failureManman Ren2012-07-29
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160927 91177308-0d34-0410-b5e6-96231b3b80d8
* X86 Peephole: fold loads to the source register operand if possible.Manman Ren2012-07-28
| | | | | | | | | | Machine CSE and other optimizations can remove instructions so folding is possible at peephole while not possible at ISel. rdar://10554090 and rdar://11873276 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160919 91177308-0d34-0410-b5e6-96231b3b80d8
* Add SrcReg2 to analyzeCompare and optimizeCompareInstr to handle CompareManman Ren2012-06-29
| | | | | | | instructions with two register operands. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159465 91177308-0d34-0410-b5e6-96231b3b80d8
* Implement PPCInstrInfo::isCoalescableExtInstr().Jakob Stoklund Olesen2012-06-19
| | | | | | | | | | | | | The PPC::EXTSW instruction preserves the low 32 bits of its input, just like some of the x86 instructions. Use it to reduce register pressure when the low 32 bits have multiple uses. This requires a small change to PeepholeOptimizer since EXTSW takes a 64-bit input register. This is related to PR5997. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158743 91177308-0d34-0410-b5e6-96231b3b80d8
* Style: Don't reuse variables for multiple purposes.Jakob Stoklund Olesen2012-06-19
| | | | | | No functional change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158742 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r157755.Manman Ren2012-06-06
| | | | | | | | | The commit is intended to fix rdar://11540023. It is implemented as part of peephole optimization. We can actually implement this in the SelectionDAG lowering phase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158122 91177308-0d34-0410-b5e6-96231b3b80d8
* X86: replace SUB with CMP if possibleManman Ren2012-05-31
| | | | | | | | | | | | | | | | | | | This patch will optimize the following movq %rdi, %rax subq %rsi, %rax cmovsq %rsi, %rdi movq %rdi, %rax to cmpq %rsi, %rdi cmovsq %rsi, %rdi movq %rdi, %rax Perform this optimization if the actual result of SUB is not used. rdar: 11540023 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157755 91177308-0d34-0410-b5e6-96231b3b80d8
* Constrain regclasses in PeepholeOptimizer.Jakob Stoklund Olesen2012-05-20
| | | | | | | It can be necessary to restrict to a sub-class before accessing sub-registers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157164 91177308-0d34-0410-b5e6-96231b3b80d8
* ARM: peephole optimization to remove cmp instructionManman Ren2012-05-11
| | | | | | | | | | | | | | | | | | | This patch will optimize the following cases: sub r1, r3 | sub r1, imm cmp r3, r1 or cmp r1, r3 | cmp r1, imm bge L1 TO subs r1, r3 bge L1 or ble L1 If the branch instruction can use flag from "sub", then we can replace "sub" with "subs" and eliminate the "cmp" instruction. rdar: 10734411 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156599 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert: 156550 "ARM: peephole optimization to remove cmp instruction"Manman Ren2012-05-10
| | | | | | | This commit broke an external linux bot and gave a compile-time warning. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156556 91177308-0d34-0410-b5e6-96231b3b80d8
* ARM: peephole optimization to remove cmp instructionManman Ren2012-05-10
| | | | | | | | | | | | | | | | | | | This patch will optimize the following cases: sub r1, r3 | sub r1, imm cmp r3, r1 or cmp r1, r3 | cmp r1, imm bge L1 TO subs r1, r3 bge L1 or ble L1 If the branch instruction can use flag from "sub", then we can replace "sub" with "subs" and eliminate the "cmp" instruction. rdar: 10734411 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156550 91177308-0d34-0410-b5e6-96231b3b80d8
* Tidy up. Naming conventions.Jim Grosbach2012-05-01
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155960 91177308-0d34-0410-b5e6-96231b3b80d8
* Make the peephole optimizer clear kill flags on a vreg if it's about to add newLang Hames2012-02-25
| | | | | | | | | | uses of the vreg, since the old kills may no longer be valid. This was causing -verify-machineinstrs to complain about uses after kills, and could potentially have been causing subtle register allocation issues, but I haven't come across a test case yet. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151425 91177308-0d34-0410-b5e6-96231b3b80d8
* Fixed typo.Lang Hames2012-02-25
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151417 91177308-0d34-0410-b5e6-96231b3b80d8
* Codegen pass definition cleanup. No functionality.Andrew Trick2012-02-08
| | | | | | | | | | | | | Moving toward a uniform style of pass definition to allow easier target configuration. Globally declare Pass ID. Globally declare pass initializer. Use INITIALIZE_PASS consistently. Add a call to the initializer from CodeGen.cpp. Remove redundant "createPass" functions and "getPassName" methods. While cleaning up declarations, cleaned up comments (sorry for large diff). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150100 91177308-0d34-0410-b5e6-96231b3b80d8
* whitespaceAndrew Trick2012-02-08
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150094 91177308-0d34-0410-b5e6-96231b3b80d8
* Add bundle aware API for querying instruction properties and switch the codeEvan Cheng2011-12-07
| | | | | | | | | | | | | | | generator to it. For non-bundle instructions, these behave exactly the same as the MC layer API. For properties like mayLoad / mayStore, look into the bundle and if any of the bundled instructions has the property it would return true. For properties like isPredicable, only return true if *all* of the bundled instructions have the property. For properties like canFoldAsLoad, isCompare, conservatively return false for bundles. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146026 91177308-0d34-0410-b5e6-96231b3b80d8
* If MI is deleted then remove it from the set. If a new MI is created, it couldNick Lewycky2011-10-13
| | | | | | | | have the same address as the one we deleted, and we don't want that in the set yet. Noticed by inspection. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141849 91177308-0d34-0410-b5e6-96231b3b80d8
* SrcDef is only written and never read. Remove it.Duncan Sands2011-07-26
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136080 91177308-0d34-0410-b5e6-96231b3b80d8
* - Rename TargetInstrDesc, TargetOperandInfo to MCInstrDesc and MCOperandInfo andEvan Cheng2011-06-28
| | | | | | | | | sink them into MC layer. - Added MCInstrInfo, which captures the tablegen generated static data. Chang TargetInstrInfo so it's based off MCInstrInfo. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134021 91177308-0d34-0410-b5e6-96231b3b80d8
* Add a peephole optimization to optimize pairs of bitcasts. e.g.Evan Cheng2011-03-15
| | | | | | | | | | | | | | | | | | | | | | | v2 = bitcast v1 ... v3 = bitcast v2 ... = v3 => v2 = bitcast v1 ... = v1 if v1 and v3 are of in the same register class. bitcast between i32 and fp (and others) are often not nops since they are in different register classes. These bitcast instructions are often left because they are in different basic blocks and cannot be eliminated by dag combine. rdar://9104514 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127668 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix thinko. Cmp can be the first instruction in a MBB.Evan Cheng2011-02-15
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125552 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix PR8854. Track inserted copies to avoid read before write. Sorry, it's ↵Evan Cheng2011-02-14
| | | | | | hard to reduce a sensible small test case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125523 91177308-0d34-0410-b5e6-96231b3b80d8
* Simplify a bunch of isVirtualRegister() and isPhysicalRegister() logic.Jakob Stoklund Olesen2011-01-10
| | | | | | | | These functions not longer assert when passed 0, but simply return false instead. No functional change intended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123155 91177308-0d34-0410-b5e6-96231b3b80d8
* Do not model all INLINEASM instructions as having unmodelled side effects.Evan Cheng2011-01-07
| | | | | | | | | | | Instead encode llvm IR level property "HasSideEffects" in an operand (shared with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check the operand when the instruction is an INLINEASM. This allows memory instructions to be moved around INLINEASM instructions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123044 91177308-0d34-0410-b5e6-96231b3b80d8
* DBG_VALUE does not have any side effects; it also makes no sense to mark it ↵Evan Cheng2011-01-07
| | | | | | cheap as a copy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123031 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove ARM isel hacks that fold large immediates into a pair of add, sub, and,Evan Cheng2010-11-17
| | | | | | | | | | | | | | | | | | | | | | and xor. The 32-bit move immediates can be hoisted out of loops by machine LICM but the isel hacks were preventing them. Instead, let peephole optimization pass recognize registers that are defined by immediates and the ARM target hook will fold the immediates in. Other changes include 1) do not fold and / xor into cmp to isel TST / TEQ instructions if there are multiple uses. This happens when the 'and' is live out, machine sink would have sinked the computation and that ends up pessimizing code. The peephole pass would recognize situations where the 'and' can be toggled to define CPSR and eliminate the comparison anyway. 2) Move peephole pass to after machine LICM, sink, and CSE to avoid blocking important optimizations. rdar://8663787, rdar://8241368 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119548 91177308-0d34-0410-b5e6-96231b3b80d8
* Code clean up. The peephole pass should be the one updating the instructionEvan Cheng2010-11-15
| | | | | | | iterator, not TII->OptimizeCompareInstr. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119186 91177308-0d34-0410-b5e6-96231b3b80d8
* When we look at instructions to convert to setting the 's' flag, we need to lookBill Wendling2010-11-01
| | | | | | | | | | | | | | | | | | | | | | | | | at more than those which define CPSR. You can have this situation: (1) subs ... (2) sub r6, r5, r4 (3) movge ... (4) cmp r6, 0 (5) movge ... We cannot convert (2) to "subs" because (3) is using the CPSR set by (1). There's an analogous situation here: (1) sub r1, r2, r3 (2) sub r4, r5, r6 (3) cmp r4, ... (5) movge ... (6) cmp r1, ... (7) movge ... We cannot convert (1) to "subs" because of the intervening use of CPSR. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117950 91177308-0d34-0410-b5e6-96231b3b80d8
* The testcase is now XFAILed. Sorry about the breakage.Bill Wendling2010-11-01
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117904 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r117876 for now, it's causing more testsuite failures.Eric Christopher2010-10-31
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117879 91177308-0d34-0410-b5e6-96231b3b80d8
* Disable the peephole optimizer until 186.crafty on armv6 is fixed. This is whatBill Wendling2010-10-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | looks like is happening: Without the peephole optimizer: (1) sub r6, r6, #32 orr r12, r12, lr, lsl r9 orr r2, r2, r3, lsl r10 (x) cmp r6, #0 ldr r9, LCPI2_10 ldr r10, LCPI2_11 (2) sub r8, r8, #32 (a) movge r12, lr, lsr r6 (y) cmp r8, #0 LPC2_10: ldr lr, [pc, r10] (b) movge r2, r3, lsr r8 With the peephole optimizer: ldr r9, LCPI2_10 ldr r10, LCPI2_11 (1*) subs r6, r6, #32 (2*) subs r8, r8, #32 (a*) movge r12, lr, lsr r6 (b*) movge r2, r3, lsr r8 (1) is used by (x) for the conditional move at (a). (2) is used by (y) for the conditional move at (b). After the peephole optimizer, these the flags resulting from (1*) are ignored and only the flags from (2*) are considered for both conditional moves. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117876 91177308-0d34-0410-b5e6-96231b3b80d8
* Get rid of static constructors for pass registration. Instead, every pass ↵Owen Anderson2010-10-19
| | | | | | | | | | | | | | | | | | exposes an initializeMyPassFunction(), which must be called in the pass's constructor. This function uses static dependency declarations to recursively initialize the pass's dependencies. Clients that only create passes through the createFooPass() APIs will require no changes. Clients that want to use the CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h before parsing commandline arguments. I have tested this with all standard configurations of clang and llvm-gcc on Darwin. It is possible that there are problems with the static dependencies that will only be visible with non-standard options. If you encounter any crash in pass registration/creation, please send the testcase to me directly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116820 91177308-0d34-0410-b5e6-96231b3b80d8
* Don't recompute MachineRegisterInfo in the Optimize* method.Bill Wendling2010-10-18
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116750 91177308-0d34-0410-b5e6-96231b3b80d8
* Begin adding static dependence information to passes, which will allow us toOwen Anderson2010-10-12
| | | | | | | | | | perform initialization without static constructors AND without explicit initialization by the client. For the moment, passes are required to initialize both their (potential) dependencies and any passes they preserve. I hope to be able to relax the latter requirement in the future. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116334 91177308-0d34-0410-b5e6-96231b3b80d8
* Now with fewer extraneous semicolons!Owen Anderson2010-10-07
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
* Move the search for the appropriate AND instructionGabor Greif2010-09-21
| | | | | | | | | | | into OptimizeCompareInstr. This necessitates the passing of CmpValue around, so widen the virtual functions to accomodate. No functionality changes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114428 91177308-0d34-0410-b5e6-96231b3b80d8
* must not peephole away side effectsGabor Greif2010-09-14
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113848 91177308-0d34-0410-b5e6-96231b3b80d8
* Rename ConvertToSetZeroFlag to something more general.Bill Wendling2010-09-11
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113670 91177308-0d34-0410-b5e6-96231b3b80d8
* No need to recompute the SrcReg and CmpValue.Bill Wendling2010-09-10
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113666 91177308-0d34-0410-b5e6-96231b3b80d8
* Move some of the decision logic for converting an instruction into one that setsBill Wendling2010-09-10
| | | | | | | | the 'zero' bit down into the back-end. There are other cases where this logic isn't sufficient, so they should be handled separately. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113665 91177308-0d34-0410-b5e6-96231b3b80d8
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