summaryrefslogtreecommitdiffstats
path: root/llvm/lib/CodeGen/TargetLoweringBase.cpp
Commit message (Collapse)AuthorAgeFilesLines
...
* Rename AttributeSet to AttributeListReid Kleckner2017-03-211-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Summary: This class is a list of AttributeSetNodes corresponding the function prototype of a call or function declaration. This class used to be called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is typically accessed by parameter and return value index, so "AttributeList" seems like a more intuitive name. Rename AttributeSetImpl to AttributeListImpl to follow suit. It's useful to rename this class so that we can rename AttributeSetNode to AttributeSet later. AttributeSet is the set of attributes that apply to a single function, argument, or return value. Reviewers: sanjoy, javed.absar, chandlerc, pete Reviewed By: pete Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits Differential Revision: https://reviews.llvm.org/D31102 llvm-svn: 298393
* [SelectionDAG] Add a signed integer absolute ISD nodeSimon Pilgrim2017-03-141-0/+1
| | | | | | | | | | | | Reduced version of D26357 - based on the discussion on llvm-dev about canonicalization of UMIN/UMAX/SMIN/SMAX as well as ABS I've reduced that patch to just the ABS ISD node (with x86/sse support) to improve basic combines and lowering. ARM/AArch64, Hexagon, PowerPC and NVPTX all have similar instructions allowing us to make this a generic opcode and move away from the hard coded tablegen patterns which makes it tricky to match more complex patterns. At the moment this patch doesn't attempt legalization as we only create an ABS node if its legal/custom. Differential Revision: https://reviews.llvm.org/D29639 llvm-svn: 297780
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2017-03-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Recommiting with compiler time improvements Recommitting after fixup of 32-bit aliasing sign offset bug in DAGCombiner. * Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search and chain alias analysis which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. When merging stores search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and the output Codegen (save perhaps for some ARM cases where we correctly constructs wider loads, but then promotes them to float operations which appear but requires more expensive constant generation). Some minor peephole optimizations to deal with improved SubDAG shapes (listed below) Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seems sufficient to not cause regressions in tests. 5. Remove Chain dependencies of Memory operations on CopyfromReg nodes as these are captured by data dependence 6. Forward loads-store values through tokenfactors containing {CopyToReg,CopyFromReg} Values. 7. Peephole to convert buildvector of extract_vector_elt to extract_subvector if possible (see CodeGen/AArch64/store-merge.ll) 8. Store merging for the ARM target is restricted to 32-bit as some in some contexts invalid 64-bit operations are being generated. This can be removed once appropriate checks are added. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable, improving load-store forwarding. One test in particular is worth noting: CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store forwarding converts a load-store pair into a parallel store and a memory-realized bitcast of the same value. However, because we lose the sharing of the explicit and implicit store values we must create another local store. A similar transformation happens before SelectionDAG as well. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle llvm-svn: 297695
* [SDAG] Revert r296476 (and r296486, r296668, r296690).Chandler Carruth2017-03-031-1/+1
| | | | | | | | | | This patch causes compile times for some patterns to explode. I have a (large, unreduced) test case that slows down by more than 20x and several test cases slow down by 2x. I'm sending some of the test cases directly to Nirav and following up with more details in the review log, but this should unblock anyone else hitting this. llvm-svn: 296862
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2017-02-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Recommiting after fixup of 32-bit aliasing sign offset bug in DAGCombiner. * Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search and chain alias analysis which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. When merging stores search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and the output Codegen (save perhaps for some ARM cases where we correctly constructs wider loads, but then promotes them to float operations which appear but requires more expensive constant generation). Some minor peephole optimizations to deal with improved SubDAG shapes (listed below) Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seems sufficient to not cause regressions in tests. 5. Remove Chain dependencies of Memory operations on CopyfromReg nodes as these are captured by data dependence 6. Forward loads-store values through tokenfactors containing {CopyToReg,CopyFromReg} Values. 7. Peephole to convert buildvector of extract_vector_elt to extract_subvector if possible (see CodeGen/AArch64/store-merge.ll) 8. Store merging for the ARM target is restricted to 32-bit as some in some contexts invalid 64-bit operations are being generated. This can be removed once appropriate checks are added. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable, improving load-store forwarding. One test in particular is worth noting: CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store forwarding converts a load-store pair into a parallel store and a memory-realized bitcast of the same value. However, because we lose the sharing of the explicit and implicit store values we must create another local store. A similar transformation happens before SelectionDAG as well. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle llvm-svn: 296476
* Revert "In visitSTORE, always use FindBetterChain, rather than only when ↵Nirav Dave2017-02-261-1/+1
| | | | | | | | UseAA is enabled." This reverts commit r296252 until 256-bit operations are more efficiently generated in X86. llvm-svn: 296279
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2017-02-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Recommiting after fixup of 32-bit aliasing sign offset bug in DAGCombiner. * Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search and chain alias analysis which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. When merging stores search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and the output Codegen (save perhaps for some ARM cases where we correctly constructs wider loads, but then promotes them to float operations which appear but requires more expensive constant generation). Some minor peephole optimizations to deal with improved SubDAG shapes (listed below) Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seems sufficient to not cause regressions in tests. 5. Remove Chain dependencies of Memory operations on CopyfromReg nodes as these are captured by data dependence 6. Forward loads-store values through tokenfactors containing {CopyToReg,CopyFromReg} Values. 7. Peephole to convert buildvector of extract_vector_elt to extract_subvector if possible (see CodeGen/AArch64/store-merge.ll) 8. Store merging for the ARM target is restricted to 32-bit as some in some contexts invalid 64-bit operations are being generated. This can be removed once appropriate checks are added. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable, improving load-store forwarding. One test in particular is worth noting: CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store forwarding converts a load-store pair into a parallel store and a memory-realized bitcast of the same value. However, because we lose the sharing of the explicit and implicit store values we must create another local store. A similar transformation happens before SelectionDAG as well. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle llvm-svn: 296252
* [CodeGenPrepare] Sink and duplicate more 'and' instructions.Geoff Berry2017-02-211-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Rework the code that was sinking/duplicating (icmp and, 0) sequences into blocks where they were being used by conditional branches to form more tbz instructions on AArch64. The new code is more general in that it just looks for 'and's that have all icmp 0's as users, with a target hook used to select which subset of 'and' instructions to consider. This change also enables 'and' sinking for X86, where it is more widely beneficial than on AArch64. The 'and' sinking/duplicating code is moved into the optimizeInst phase of CodeGenPrepare, where it can take advantage of the fact the OptimizeCmpExpression has already sunk/duplicated any icmps into the blocks where they are used. One minor complication from this change is that optimizeLoadExt needed to be updated to always mark 'and's it has determined should be in the same block as their feeding load in the InsertedInsts set to avoid an infinite loop of hoisting and sinking the same 'and'. This change fixes a regression on X86 in the tsan runtime caused by moving GVNHoist to a later place in the optimization pipeline (see PR31382). Reviewers: t.p.northover, qcolombet, MatzeB Subscribers: aemerson, mcrosier, sebpop, llvm-commits Differential Revision: https://reviews.llvm.org/D28813 llvm-svn: 295746
* Revert "In visitSTORE, always use FindBetterChain, rather than only when ↵Nirav Dave2017-02-021-1/+1
| | | | | | | | | UseAA is enabled." This reverts commit r293893 which is miscompiling lua on ARM and bootstrapping for x86-windows. llvm-svn: 293915
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2017-02-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Recommiting after fixing X86 inc/dec chain bug. * Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search and chain alias analysis which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. When merging stores search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and the output Codegen (save perhaps for some ARM cases where we correctly constructs wider loads, but then promotes them to float operations which appear but requires more expensive constant generation). Some minor peephole optimizations to deal with improved SubDAG shapes (listed below) Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seems sufficient to not cause regressions in tests. 5. Remove Chain dependencies of Memory operations on CopyfromReg nodes as these are captured by data dependence 6. Forward loads-store values through tokenfactors containing {CopyToReg,CopyFromReg} Values. 7. Peephole to convert buildvector of extract_vector_elt to extract_subvector if possible (see CodeGen/AArch64/store-merge.ll) 8. Store merging for the ARM target is restricted to 32-bit as some in some contexts invalid 64-bit operations are being generated. This can be removed once appropriate checks are added. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable, improving load-store forwarding. One test in particular is worth noting: CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store forwarding converts a load-store pair into a parallel store and a memory-realized bitcast of the same value. However, because we lose the sharing of the explicit and implicit store values we must create another local store. A similar transformation happens before SelectionDAG as well. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle llvm-svn: 293893
* Revert "In visitSTORE, always use FindBetterChain, rather than only when ↵Nirav Dave2017-01-261-1/+1
| | | | | | | | UseAA is enabled." This reverts commit r293184 which is failing in LTO builds llvm-svn: 293188
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2017-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. * Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search and chain alias analysis which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. When merging stores search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and the output Codegen (save perhaps for some ARM cases where we correctly constructs wider loads, but then promotes them to float operations which appear but requires more expensive constant generation). Some minor peephole optimizations to deal with improved SubDAG shapes (listed below) Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seems sufficient to not cause regressions in tests. 5. Remove Chain dependencies of Memory operations on CopyfromReg nodes as these are captured by data dependence 6. Forward loads-store values through tokenfactors containing {CopyToReg,CopyFromReg} Values. 7. Peephole to convert buildvector of extract_vector_elt to extract_subvector if possible (see CodeGen/AArch64/store-merge.ll) 8. Store merging for the ARM target is restricted to 32-bit as some in some contexts invalid 64-bit operations are being generated. This can be removed once appropriate checks are added. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable, improving load-store forwarding. One test in particular is worth noting: CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store forwarding converts a load-store pair into a parallel store and a memory-realized bitcast of the same value. However, because we lose the sharing of the explicit and implicit store values we must create another local store. A similar transformation happens before SelectionDAG as well. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle llvm-svn: 293184
* [CodeGen] Simplify getRecipEstimateForFuncDavid Majnemer2017-01-131-5/+1
| | | | | | It used two attribute lookups when only one was needed. llvm-svn: 291965
* [CodeGen] Rename MachineInstrBuilder::addOperand. NFCDiana Picus2017-01-131-4/+4
| | | | | | | | | | | Rename from addOperand to just add, to match the other method that has been added to MachineInstrBuilder for adding more than just 1 operand. See https://reviews.llvm.org/D28057 for the whole discussion. Differential Revision: https://reviews.llvm.org/D28556 llvm-svn: 291891
* Introduce element-wise atomic memcpy intrinsicIgor Laevsky2016-12-291-0/+23
| | | | | | | | | | This change adds a new intrinsic which is intended to provide memcpy functionality with additional atomicity guarantees. Please refer to the review thread or language reference for further details. Differential Revision: https://reviews.llvm.org/D27133 llvm-svn: 290708
* Revert "In visitSTORE, always use FindBetterChain, rather than only when ↵Nirav Dave2016-12-141-1/+1
| | | | | | | | | | UseAA is enabled." Reverting due to ARM MCJIT and MIPS LLD error. This reverts commit r289659. llvm-svn: 289667
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2016-12-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Retrying after fixing after removing load-store factoring through token factors in favor of improved token factor operand pruning Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. Whem merging stores, search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and generally the output CodeGen (with some exceptions). Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seemed sufficient to not cause regressions in tests. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable. Some tests relying on the order were changed to use volatile memory operations Noteworthy tests: CodeGen/AArch64/argument-blocks.ll - It's not entirely clear what the test_varargs_stackalign test is supposed to be asserting, but the new code looks right. CodeGen/AArch64/arm64-memset-inline.lli - CodeGen/AArch64/arm64-stur.ll - CodeGen/ARM/memset-inline.ll - The backend now generates *worse* code due to store merging succeeding, as we do do a 16-byte constant-zero store efficiently. CodeGen/AArch64/merge-store.ll - Improved, but there still seems to be an extraneous vector insert from an element to itself? CodeGen/PowerPC/ppc64-align-long-double.ll - Worse code emitted in this case, due to the improved store->load forwarding. CodeGen/X86/dag-merge-fast-accesses.ll - CodeGen/X86/MergeConsecutiveStores.ll - CodeGen/X86/stores-merging.ll - CodeGen/Mips/load-store-left-right.ll - Restored correct merging of non-aligned stores CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll - Improved. Correctly merges buffer_store_dword calls CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll - Improved. Sidesteps loading a stored value and merges two stores CodeGen/X86/pr18023.ll - This test has been removed, as it was asserting incorrect behavior. Non-volatile stores *CAN* be moved past volatile loads, and now are. CodeGen/X86/vector-idiv.ll - CodeGen/X86/vector-lzcnt-128.ll - It's basically impossible to tell what these tests are actually testing. But, looks like the code got better due to the memory operations being recognized as non-aliasing. CodeGen/X86/win32-eh.ll - Both loads of the securitycookie are now merged. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, dsanders, resistor, tstellarAMD, t.p.northover, spatel Differential Revision: https://reviews.llvm.org/D14834 llvm-svn: 289659
* Revert "In visitSTORE, always use FindBetterChain, rather than only when ↵Nirav Dave2016-12-091-1/+1
| | | | | | | | UseAA is enabled." This reverts commit r289221 which appears to be triggering an assertion llvm-svn: 289226
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2016-12-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Retrying after fixing overly aggressive load-store forwarding optimization. Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. Whem merging stores, search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and generally the output CodeGen (with some exceptions). Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seemed sufficient to not cause regressions in tests. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable. Some tests relying on the order were changed to use volatile memory operations Noteworthy tests: CodeGen/AArch64/argument-blocks.ll - It's not entirely clear what the test_varargs_stackalign test is supposed to be asserting, but the new code looks right. CodeGen/AArch64/arm64-memset-inline.lli - CodeGen/AArch64/arm64-stur.ll - CodeGen/ARM/memset-inline.ll - The backend now generates *worse* code due to store merging succeeding, as we do do a 16-byte constant-zero store efficiently. CodeGen/AArch64/merge-store.ll - Improved, but there still seems to be an extraneous vector insert from an element to itself? CodeGen/PowerPC/ppc64-align-long-double.ll - Worse code emitted in this case, due to the improved store->load forwarding. CodeGen/X86/dag-merge-fast-accesses.ll - CodeGen/X86/MergeConsecutiveStores.ll - CodeGen/X86/stores-merging.ll - CodeGen/Mips/load-store-left-right.ll - Restored correct merging of non-aligned stores CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll - Improved. Correctly merges buffer_store_dword calls CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll - Improved. Sidesteps loading a stored value and merges two stores CodeGen/X86/pr18023.ll - This test has been removed, as it was asserting incorrect behavior. Non-volatile stores *CAN* be moved past volatile loads, and now are. CodeGen/X86/vector-idiv.ll - CodeGen/X86/vector-lzcnt-128.ll - It's basically impossible to tell what these tests are actually testing. But, looks like the code got better due to the memory operations being recognized as non-aliasing. CodeGen/X86/win32-eh.ll - Both loads of the securitycookie are now merged. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, dsanders, resistor, tstellarAMD, t.p.northover, spatel Differential Revision: https://reviews.llvm.org/D14834 llvm-svn: 289221
* Add option to specify minimum number of entries for jump tablesEvandro Menezes2016-10-251-3/+14
| | | | | | | | | | Add an option to allow easier experimentation by target maintainers with the minimum number of entries to create jump tables. Also clarify the name of the other existing option governing the creation of jump tables. Differential revision: https://reviews.llvm.org/D25883 llvm-svn: 285104
* fix variable names; NFCISanjay Patel2016-10-211-2/+2
| | | | | | | | Because we're just 'or-ing' these 2 variables later in the code, I don't think there's a logical bug here, but of course the string with "no size" is the one that should have the size suffix stripped off. llvm-svn: 284826
* [Target] remove TargetRecip class; 2nd trySanjay Patel2016-10-201-17/+189
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a retry of r284495 which was reverted at r284513 due to use-after-scope bugs caused by faulty usage of StringRef. This version also renames a pair of functions: getRecipEstimateDivEnabled() getRecipEstimateSqrtEnabled() as suggested by Eric Christopher. original commit msg: [Target] remove TargetRecip class; move reciprocal estimate isel functionality to TargetLowering This is a follow-up to https://reviews.llvm.org/D24816 - where we changed reciprocal estimates to be function attributes rather than TargetOptions. This patch is intended to be a structural, but not functional change. By moving all of the TargetRecip functionality into TargetLowering, we can remove all of the reciprocal estimate state, shield the callers from the string format implementation, and simplify/localize the logic needed for a target to enable this. If a function has a "reciprocal-estimates" attribute, those settings may override the target's default reciprocal preferences for whatever operation and data type we're trying to optimize. If there's no attribute string or specific setting for the op/type pair, just use the target default settings. As noted earlier, a better solution would be to move the reciprocal estimate settings to IR instructions and SDNodes rather than function attributes, but that's a multi-step job that requires infrastructure improvements. I intend to work on that, but it's not clear how long it will take to get all the pieces in place. Differential Revision: https://reviews.llvm.org/D25440 llvm-svn: 284746
* revert r284495: [Target] remove TargetRecip classSanjay Patel2016-10-181-185/+17
| | | | | | There's something wrong with the StringRef usage while parsing the attribute string. llvm-svn: 284513
* [Target] remove TargetRecip class; move reciprocal estimate isel ↵Sanjay Patel2016-10-181-17/+185
| | | | | | | | | | | | | | | | | | | | | | | | | | functionality to TargetLowering This is a follow-up to D24816 - where we changed reciprocal estimates to be function attributes rather than TargetOptions. This patch is intended to be a structural, but not functional change. By moving all of the TargetRecip functionality into TargetLowering, we can remove all of the reciprocal estimate state, shield the callers from the string format implementation, and simplify/localize the logic needed for a target to enable this. If a function has a "reciprocal-estimates" attribute, those settings may override the target's default reciprocal preferences for whatever operation and data type we're trying to optimize. If there's no attribute string or specific setting for the op/type pair, just use the target default settings. As noted earlier, a better solution would be to move the reciprocal estimate settings to IR instructions and SDNodes rather than function attributes, but that's a multi-step job that requires infrastructure improvements. I intend to work on that, but it's not clear how long it will take to get all the pieces in place. Differential Revision: https://reviews.llvm.org/D25440 llvm-svn: 284495
* [safestack] Use non-thread-local unsafe stack pointer for Contiki OSDavid L Kreitzer2016-10-141-1/+33
| | | | | | | | Patch by Michael LeMay Differential revision: http://reviews.llvm.org/D19852 llvm-svn: 284254
* Revert "In visitSTORE, always use FindBetterChain, rather than only when ↵Nirav Dave2016-10-131-1/+1
| | | | | | | | | UseAA is enabled." This reverts commit r284151 which appears to be triggering a LTO failures on Hexagon llvm-svn: 284157
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2016-10-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Retrying after upstream changes. Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. Whem merging stores, search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and generally the output CodeGen (with some exceptions). Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seemed sufficient to not cause regressions in tests. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable. Some tests relying on the order were changed to use volatile memory operations Noteworthy tests: CodeGen/AArch64/argument-blocks.ll - It's not entirely clear what the test_varargs_stackalign test is supposed to be asserting, but the new code looks right. CodeGen/AArch64/arm64-memset-inline.lli - CodeGen/AArch64/arm64-stur.ll - CodeGen/ARM/memset-inline.ll - The backend now generates *worse* code due to store merging succeeding, as we do do a 16-byte constant-zero store efficiently. CodeGen/AArch64/merge-store.ll - Improved, but there still seems to be an extraneous vector insert from an element to itself? CodeGen/PowerPC/ppc64-align-long-double.ll - Worse code emitted in this case, due to the improved store->load forwarding. CodeGen/X86/dag-merge-fast-accesses.ll - CodeGen/X86/MergeConsecutiveStores.ll - CodeGen/X86/stores-merging.ll - CodeGen/Mips/load-store-left-right.ll - Restored correct merging of non-aligned stores CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll - Improved. Correctly merges buffer_store_dword calls CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll - Improved. Sidesteps loading a stored value and merges two stores CodeGen/X86/pr18023.ll - This test has been removed, as it was asserting incorrect behavior. Non-volatile stores *CAN* be moved past volatile loads, and now are. CodeGen/X86/vector-idiv.ll - CodeGen/X86/vector-lzcnt-128.ll - It's basically impossible to tell what these tests are actually testing. But, looks like the code got better due to the memory operations being recognized as non-aliasing. CodeGen/X86/win32-eh.ll - Both loads of the securitycookie are now merged. CodeGen/AMDGPU/vgpr-spill-emergency-stack-slot-compute.ll - This test appears to work but no longer exhibits the spill behavior. Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, dsanders, resistor, tstellarAMD, t.p.northover, spatel Differential Revision: https://reviews.llvm.org/D14834 llvm-svn: 284151
* Target: Remove unused entities.Peter Collingbourne2016-10-091-1/+0
| | | | llvm-svn: 283690
* [Target] move reciprocal estimate settings from TargetOptions to TargetLoweringSanjay Patel2016-10-041-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | The motivation for the change is that we can't have pseudo-global settings for codegen living in TargetOptions because that doesn't work with LTO. Ideally, these reciprocal attributes will be moved to the instruction-level via FMF, metadata, or something else. But making them function attributes is at least an improvement over the current state. The ingredients of this patch are: Remove the reciprocal estimate command-line debug option. Add TargetRecip to TargetLowering. Remove TargetRecip from TargetOptions. Clean up the TargetRecip implementation to work with this new scheme. Set the default reciprocal settings in TargetLoweringBase (everything is off). Update the PowerPC defaults, users, and tests. Update the x86 defaults, users, and tests. Note that if this patch needs to be reverted, the related clang patch checked in at r283251 should be reverted too. Differential Revision: https://reviews.llvm.org/D24816 llvm-svn: 283252
* Revert "In visitSTORE, always use FindBetterChain, rather than only when ↵Nirav Dave2016-09-281-1/+1
| | | | | | | | UseAA is enabled." This reverts commit r282600 due to test failues with MCJIT llvm-svn: 282604
* In visitSTORE, always use FindBetterChain, rather than only when UseAA is ↵Nirav Dave2016-09-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabled. Simplify Consecutive Merge Store Candidate Search Now that address aliasing is much less conservative, push through simplified store merging search which only checks for parallel stores through the chain subgraph. This is cleaner as the separation of non-interfering loads/stores from the store-merging logic. Whem merging stores, search up the chain through a single load, and finds all possible stores by looking down from through a load and a TokenFactor to all stores visited. This improves the quality of the output SelectionDAG and generally the output CodeGen (with some exceptions). Additional Minor Changes: 1. Finishes removing unused AliasLoad code 2. Unifies the the chain aggregation in the merged stores across code paths 3. Re-add the Store node to the worklist after calling SimplifyDemandedBits. 4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is arbitrary, but seemed sufficient to not cause regressions in tests. This finishes the change Matt Arsenault started in r246307 and jyknight's original patch. Many tests required some changes as memory operations are now reorderable. Some tests relying on the order were changed to use volatile memory operations Noteworthy tests: CodeGen/AArch64/argument-blocks.ll - It's not entirely clear what the test_varargs_stackalign test is supposed to be asserting, but the new code looks right. CodeGen/AArch64/arm64-memset-inline.lli - CodeGen/AArch64/arm64-stur.ll - CodeGen/ARM/memset-inline.ll - The backend now generates *worse* code due to store merging succeeding, as we do do a 16-byte constant-zero store efficiently. CodeGen/AArch64/merge-store.ll - Improved, but there still seems to be an extraneous vector insert from an element to itself? CodeGen/PowerPC/ppc64-align-long-double.ll - Worse code emitted in this case, due to the improved store->load forwarding. CodeGen/X86/dag-merge-fast-accesses.ll - CodeGen/X86/MergeConsecutiveStores.ll - CodeGen/X86/stores-merging.ll - CodeGen/Mips/load-store-left-right.ll - Restored correct merging of non-aligned stores CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll - Improved. Correctly merges buffer_store_dword calls CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll - Improved. Sidesteps loading a stored value and merges two stores CodeGen/X86/pr18023.ll - This test has been removed, as it was asserting incorrect behavior. Non-volatile stores *CAN* be moved past volatile loads, and now are. CodeGen/X86/vector-idiv.ll - CodeGen/X86/vector-lzcnt-128.ll - It's basically impossible to tell what these tests are actually testing. But, looks like the code got better due to the memory operations being recognized as non-aliasing. CodeGen/X86/win32-eh.ll - Both loads of the securitycookie are now merged. CodeGen/AMDGPU/vgpr-spill-emergency-stack-slot-compute.ll - This test appears to work but no longer exhibits the spill behavior. Reviewers: arsenm, hfinkel, tstellarAMD, nhaehnle, jyknight Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, resistor, tstellarAMD, t.p.northover, spatel Differential Revision: https://reviews.llvm.org/D14834 llvm-svn: 282600
* Add support to optionally limit the size of jump tables.Evandro Menezes2016-09-261-0/+12
| | | | | | | | | | | | | | | | | | | Many high-performance processors have a dedicated branch predictor for indirect branches, commonly used with jump tables. As sophisticated as such branch predictors are, they tend to have well defined limits beyond which their effectiveness is hampered or even nullified. One such limit is the number of possible destinations for a given indirect branches that such branch predictors can handle. This patch considers a limit that a target may set to the number of destination addresses in a jump table. Patch by: Evandro Menezes <e.menezes@samsung.com>, Aditya Kumar <aditya.k7@samsung.com>, Sebastian Pop <s.pop@samsung.com>. Differential revision: https://reviews.llvm.org/D21940 llvm-svn: 282412
* getVectorElementType().getSizeInBits() -> getScalarSizeInBits() ; NFCISanjay Patel2016-09-141-1/+1
| | | | llvm-svn: 281495
* ARM: move the builtins libcall CC setupSaleem Abdulrasool2016-09-091-166/+2
| | | | | | | | | Move the target specific setup into the target specific lowering setup. As pointed out by Anton, the initial change was moving this too high up the stack resulting in a violation of the layering (the target generic code path setup target specific bits). Sink this into the ARM specific setup. NFC. llvm-svn: 281088
* CodeGen: ensure that libcalls are always AAPCS CCSaleem Abdulrasool2016-09-071-7/+169
| | | | | | | The original commit was too aggressive about marking LibCalls as AAPCS. The libcalls contain libc/libm/libunwind calls which are not AAPCS, but C. llvm-svn: 280833
* Revert "CodeGen: ensure that libcalls are always AAPCS CC"Saleem Abdulrasool2016-09-071-6/+7
| | | | | | | This reverts SVN r280683. Revert until I figure out why this is breaking lli tests. llvm-svn: 280778
* CodeGen: ensure that libcalls are always AAPCS CCSaleem Abdulrasool2016-09-061-7/+6
| | | | | | | | | | | | | All of the builtins are designed to be invoked with ARM AAPCS CC even on ARM AAPCS VFP CC hosts. Tweak the default initialisation to ARM AAPCS CC rather than C CC for ARM/thumb targets. The changes to the tests are necessary to ensure that the calling convention for the lowered library calls are honoured. Furthermore, these adjustments cause certain branch invocations to change to branch-and-link since the returned value needs to be moved across registers (d0 -> r0, r1). llvm-svn: 280683
* [TargetLowering] remove fdiv and frem from canOpTrap() (PR29114)Sanjay Patel2016-08-291-4/+0
| | | | | | | | | | | | | | | | | Assuming the default FP env, we should not treat fdiv and frem any differently in terms of trapping behavior than any other FP op. Ie, FP ops do not trap with the default FP env. This matches how we treat these ops in IR with isSafeToSpeculativelyExecute(). There's a similar bug in Constant::canTrap(). This bug manifests in PR29114: https://llvm.org/bugs/show_bug.cgi?id=29114 ...as a sequence of scalar divisions instead of a vector division on x86 for a <3 x float> type. Differential Revision: https://reviews.llvm.org/D23974 llvm-svn: 279970
* [SSP] Do not set __guard_local to hidden for OpenBSD SSPTim Shen2016-08-221-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | __guard_local is defined as long on OpenBSD. If the source file contains a definition of __guard_local, it mismatches with the int8 pointer type used in LLVM. In that case, Module::getOrInsertGlobal() returns a cast operation instead of a GlobalVariable. Trying to set the visibility on the cast operation leads to random segfaults (seen when compiling the OpenBSD kernel, which also runs with stack protection). In the kernel, the hidden attribute does not matter. For userspace code, __guard_local is defined as hidden in the startup code. If a program re-defines __guard_local, the definition from the startup code will either win or the linker complains about multiple definitions (depending on whether the re-defined __guard_local is placed in the common segment or not). It also matches what gcc on OpenBSD does. Thanks Stefan Kempf <sisnkemp@gmail.com> for the patch! Differential Revision: http://reviews.llvm.org/D23674 llvm-svn: 279449
* [X86] Heuristic to selectively build Newton-Raphson SQRT estimationNikolai Bozhenov2016-08-041-1/+0
| | | | | | | | | | | | | | | | | | | | | On modern Intel processors hardware SQRT in many cases is faster than RSQRT followed by Newton-Raphson refinement. The patch introduces a simple heuristic to choose between hardware SQRT instruction and Newton-Raphson software estimation. The patch treats scalars and vectors differently. The heuristic is that for scalars the compiler should optimize for latency while for vectors it should optimize for throughput. It is based on the assumption that throughput bound code is likely to be vectorized. Basically, the patch disables scalar NR for big cores and disables NR completely for Skylake. Firstly, scalar SQRT has shorter latency than NR code in big cores. Secondly, vector SQRT has been greatly improved in Skylake and has better throughput compared to NR. Differential Revision: https://reviews.llvm.org/D21379 llvm-svn: 277725
* MachineFunction: Return reference for getFrameInfo(); NFCMatthias Braun2016-07-281-1/+1
| | | | | | | getFrameInfo() never returns nullptr so we should use a reference instead of a pointer. llvm-svn: 277017
* [CodeGen] Take a MachineMemOperand::Flags in ↵Justin Lebar2016-07-151-1/+1
| | | | | | | | | | | | | | | | | MachineFunction::getMachineMemOperand. Summary: Previously we took an unsigned. Hooray for type-safety. Reviewers: chandlerc Subscribers: dsanders, llvm-commits Differential Revision: http://reviews.llvm.org/D22282 llvm-svn: 275591
* CodeGen: Use MachineInstr& in TargetLowering, NFCDuncan P. N. Exon Smith2016-06-301-2/+3
| | | | | | | | | | | | | This is a mechanical change to make TargetLowering API take MachineInstr& (instead of MachineInstr*), since the argument is expected to be a valid MachineInstr. In one case, changed a parameter from MachineInstr* to MachineBasicBlock::iterator, since it was used as an insertion point. As a side effect, this removes a bunch of MachineInstr* to MachineBasicBlock::iterator implicit conversions, a necessary step toward fixing PR26753. llvm-svn: 274287
* [arm+x86] Make GNU variants behave like GNU w.r.t combining sin+cos into sincos.Daniel Sanders2016-06-211-1/+1
| | | | | | | | | | | | | | | | Summary: canCombineSinCosLibcall() would previously combine sin+cos into sincos for GNUX32/GNUEABI/GNUEABIHF regardless of whether UnsafeFPMath were set or not. However, GNU would only combine them for UnsafeFPMath because sincos does not set errno like sin and cos do. It seems likely that this is an oversight. Reviewers: t.p.northover Subscribers: t.p.northover, aemerson, llvm-commits, rengolin Differential Revision: http://reviews.llvm.org/D21431 llvm-svn: 273259
* Support expanding partial-word cmpxchg to full-word cmpxchg in AtomicExpandPass.James Y Knight2016-06-171-0/+2
| | | | | | | | | | | | | | | | | Many CPUs only have the ability to do a 4-byte cmpxchg (or ll/sc), not 1 or 2-byte. For those, you need to mask and shift the 1 or 2 byte values appropriately to use the 4-byte instruction. This change adds support for cmpxchg-based instruction sets (only SPARC, in LLVM). The support can be extended for LL/SC-based PPC and MIPS in the future, supplanting the ISel expansions those architectures currently use. Tests added for the IR transform and SPARCv9. Differential Revision: http://reviews.llvm.org/D21029 llvm-svn: 273025
* [CodeGen] Change getSDagStackGuard to get an internal sym.Davide Italiano2016-06-091-1/+1
| | | | | | | Fixes a crash in the backend during an LTO build of rtld(1) in FreeBSD. llvm-svn: 272262
* [stack-protection] Add support for MSVC buffer security checkEtienne Bergeron2016-06-071-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This patch is adding support for the MSVC buffer security check implementation The buffer security check is turned on with the '/GS' compiler switch. * https://msdn.microsoft.com/en-us/library/8dbf701c.aspx * To be added to clang here: http://reviews.llvm.org/D20347 Some overview of buffer security check feature and implementation: * https://msdn.microsoft.com/en-us/library/aa290051(VS.71).aspx * http://www.ksyash.com/2011/01/buffer-overflow-protection-3/ * http://blog.osom.info/2012/02/understanding-vs-c-compilers-buffer.html For the following example: ``` int example(int offset, int index) { char buffer[10]; memset(buffer, 0xCC, index); return buffer[index]; } ``` The MSVC compiler is adding these instructions to perform stack integrity check: ``` push ebp mov ebp,esp sub esp,50h [1] mov eax,dword ptr [__security_cookie (01068024h)] [2] xor eax,ebp [3] mov dword ptr [ebp-4],eax push ebx push esi push edi mov eax,dword ptr [index] push eax push 0CCh lea ecx,[buffer] push ecx call _memset (010610B9h) add esp,0Ch mov eax,dword ptr [index] movsx eax,byte ptr buffer[eax] pop edi pop esi pop ebx [4] mov ecx,dword ptr [ebp-4] [5] xor ecx,ebp [6] call @__security_check_cookie@4 (01061276h) mov esp,ebp pop ebp ret ``` The instrumentation above is: * [1] is loading the global security canary, * [3] is storing the local computed ([2]) canary to the guard slot, * [4] is loading the guard slot and ([5]) re-compute the global canary, * [6] is validating the resulting canary with the '__security_check_cookie' and performs error handling. Overview of the current stack-protection implementation: * lib/CodeGen/StackProtector.cpp * There is a default stack-protection implementation applied on intermediate representation. * The target can overload 'getIRStackGuard' method if it has a standard location for the stack protector cookie. * An intrinsic 'Intrinsic::stackprotector' is added to the prologue. It will be expanded by the instruction selection pass (DAG or Fast). * Basic Blocks are added to every instrumented function to receive the code for handling stack guard validation and errors handling. * Guard manipulation and comparison are added directly to the intermediate representation. * lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp * lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp * There is an implementation that adds instrumentation during instruction selection (for better handling of sibbling calls). * see long comment above 'class StackProtectorDescriptor' declaration. * The target needs to override 'getSDagStackGuard' to activate SDAG stack protection generation. (note: getIRStackGuard MUST be nullptr). * 'getSDagStackGuard' returns the appropriate stack guard (security cookie) * The code is generated by 'SelectionDAGBuilder.cpp' and 'SelectionDAGISel.cpp'. * include/llvm/Target/TargetLowering.h * Contains function to retrieve the default Guard 'Value'; should be overriden by each target to select which implementation is used and provide Guard 'Value'. * lib/Target/X86/X86ISelLowering.cpp * Contains the x86 specialisation; Guard 'Value' used by the SelectionDAG algorithm. Function-based Instrumentation: * The MSVC doesn't inline the stack guard comparison in every function. Instead, a call to '__security_check_cookie' is added to the epilogue before every return instructions. * To support function-based instrumentation, this patch is * adding a function to get the function-based check (llvm 'Value', see include/llvm/Target/TargetLowering.h), * If provided, the stack protection instrumentation won't be inlined and a call to that function will be added to the prologue. * modifying (SelectionDAGISel.cpp) do avoid producing basic blocks used for inline instrumentation, * generating the function-based instrumentation during the ISEL pass (SelectionDAGBuilder.cpp), * if FastISEL (not SelectionDAG), using the fallback which rely on the same function-based implemented over intermediate representation (StackProtector.cpp). Modifications * adding support for MSVC (lib/Target/X86/X86ISelLowering.cpp) * adding support function-based instrumentation (lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp, .h) Results * IR generated instrumentation: ``` clang-cl /GS test.cc /Od /c -mllvm -print-isel-input ``` ``` *** Final LLVM Code input to ISel *** ; Function Attrs: nounwind sspstrong define i32 @"\01?example@@YAHHH@Z"(i32 %offset, i32 %index) #0 { entry: %StackGuardSlot = alloca i8* <<<-- Allocated guard slot %0 = call i8* @llvm.stackguard() <<<-- Loading Stack Guard value call void @llvm.stackprotector(i8* %0, i8** %StackGuardSlot) <<<-- Prologue intrinsic call (store to Guard slot) %index.addr = alloca i32, align 4 %offset.addr = alloca i32, align 4 %buffer = alloca [10 x i8], align 1 store i32 %index, i32* %index.addr, align 4 store i32 %offset, i32* %offset.addr, align 4 %arraydecay = getelementptr inbounds [10 x i8], [10 x i8]* %buffer, i32 0, i32 0 %1 = load i32, i32* %index.addr, align 4 call void @llvm.memset.p0i8.i32(i8* %arraydecay, i8 -52, i32 %1, i32 1, i1 false) %2 = load i32, i32* %index.addr, align 4 %arrayidx = getelementptr inbounds [10 x i8], [10 x i8]* %buffer, i32 0, i32 %2 %3 = load i8, i8* %arrayidx, align 1 %conv = sext i8 %3 to i32 %4 = load volatile i8*, i8** %StackGuardSlot <<<-- Loading Guard slot call void @__security_check_cookie(i8* %4) <<<-- Epilogue function-based check ret i32 %conv } ``` * SelectionDAG generated instrumentation: ``` clang-cl /GS test.cc /O1 /c /FA ``` ``` "?example@@YAHHH@Z": # @"\01?example@@YAHHH@Z" # BB#0: # %entry pushl %esi subl $16, %esp movl ___security_cookie, %eax <<<-- Loading Stack Guard value movl 28(%esp), %esi movl %eax, 12(%esp) <<<-- Store to Guard slot leal 2(%esp), %eax pushl %esi pushl $204 pushl %eax calll _memset addl $12, %esp movsbl 2(%esp,%esi), %esi movl 12(%esp), %ecx <<<-- Loading Guard slot calll @__security_check_cookie@4 <<<-- Epilogue function-based check movl %esi, %eax addl $16, %esp popl %esi retl ``` Reviewers: kcc, pcc, eugenis, rnk Subscribers: majnemer, llvm-commits, hans, thakis, rnk Differential Revision: http://reviews.llvm.org/D20346 llvm-svn: 272053
* [CodeGen] Don't mark FMINNUM/FMAXNUM Expand twice. NFC.Ahmed Bougacha2016-05-311-2/+0
| | | | | | They're already in the all_valuetypes() loop above. llvm-svn: 271316
* [CodeGen] Default CTTZ_ZERO_UNDEF/CTLZ_ZERO_UNDEF to Expand in ↵Craig Topper2016-04-281-0/+4
| | | | | | TargetLoweringBase. This is what the majority of the targets want and removes a bunch of code. Set it to Legal explicitly in the few cases where that's the desired behavior. llvm-svn: 267853
* [CodeGenPrepare] use branch weight metadata to decide if a select should be ↵Sanjay Patel2016-04-261-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | turned into a branch This is part of solving PR27344: https://llvm.org/bugs/show_bug.cgi?id=27344 CGP should undo the SimplifyCFG transform for the same reason that earlier patches have used this same mechanism: it's possible that passes between SimplifyCFG and CGP may be able to optimize the IR further with a select in place. For the TLI hook default, >99% taken or not taken is chosen as the default threshold for a highly predictable branch. Even the most limited HW branch predictors will be correct on this branch almost all the time, so even a massive mispredict penalty perf loss would be overcome by the win from all the times the branch was predicted correctly. As a follow-up, we could make the default target hook less conservative by using the SchedMachineModel's MispredictPenalty. Or we could just let targets override the default by implementing the hook with that and other target-specific options. Note that trying to statically determine mispredict rates for close-to-balanced profile weight data is generally impossible if the HW is sufficiently advanced. Ie, 50/50 taken/not-taken might still be 100% predictable. Finally, note that this patch as-is will not solve PR27344 because the current __builtin_unpredictable() branch weight default values are 4 and 64. A proposal to change that is in D19435. Differential Revision: http://reviews.llvm.org/D19488 llvm-svn: 267572
OpenPOWER on IntegriCloud