Arnold Schwaighofer 8228ffe72d SimplifyCFG: If convert single conditional stores ... This resurrects r179957, but adds code that makes sure we don't touch atomic/volatile stores: This transformation will transform a conditional store with a preceeding uncondtional store to the same location: a[i] = may-alias with a[i] load if (cond) a[i] = Y into an unconditional store. a[i] = X may-alias with a[i] load tmp = cond ? Y : X; a[i] = tmp We assume that on average the cost of a mispredicted branch is going to be higher than the cost of a second store to the same location, and that the secondary benefits of creating a bigger basic block for other optimizations to work on outway the potential case where the branch would be correctly predicted and the cost of the executing the second store would be noticably reflected in performance. hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With this change we are on par with gcc's performance (gcc also performs this transformation). There was a 1.2 % performance improvement on a ARM swift chip. Other tests in the test-suite+external seem to be mostly uninfluenced in my experiments: This optimization was triggered on 41 tests such that the executable was different before/after the patch. Only 1 out of the 40 tests (dealII) was reproducable below 100% (by about .4%). Given that hmmer benefits so much I believe this to be a fair trade off. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180731 91177308-0d34-0410-b5e6-96231b3b80d8		2013-04-29 21:28:24 +00:00
..
SPARC	Use TargetTransformInfo to control switch-to-lookup table transformation	2012-10-30 11:23:25 +00:00
X86	Fix logic to determine whether to turn a switch into a lookup table. When	2012-11-30 02:02:42 +00:00
2002-05-21-PHIElimination.ll
2002-09-24-PHIAssertion.ll
2003-03-07-DominateProblem.ll
2003-08-05-InvokeCrash.ll
2003-08-17-BranchFold.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2003-08-17-BranchFoldOrdering.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2003-08-17-FoldSwitch-dbg.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2003-08-17-FoldSwitch.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2004-12-10-SimplifyCFGCrash.ll
2005-06-16-PHICrash.ll
2005-08-01-PHIUpdateFail.ll
2005-10-02-InvokeSimplify.ll
2005-12-03-IncorrectPHIFold.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2006-02-17-InfiniteUnroll.ll
2006-06-12-InfLoop.ll
2006-08-03-Crash.ll
2006-10-19-UncondDiv.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2006-12-08-Ptr-ICmp-Branch.ll
2007-11-22-InvokeNoUnwind.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2007-12-21-Crash.ll
2008-01-02-hoist-fp-add.ll	Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.	2013-04-09 05:18:53 +00:00
2008-05-16-PHIBlockMerge.ll	Convert all tests using TCL-style quoting to use shell-style quoting.	2012-07-02 12:47:22 +00:00
2008-07-13-InfLoopMiscompile.ll	Convert all tests using TCL-style quoting to use shell-style quoting.	2012-07-02 12:47:22 +00:00
2008-09-08-MultiplePred.ll
2008-09-17-SpeculativeHoist.ll
2008-10-03-SpeculativelyExecuteBeforePHI.ll
2008-12-06-SingleEntryPhi.ll
2008-12-16-DCECond.ll
2009-01-18-PHIPropCrash.ll
2009-01-19-UnconditionalTrappingConstantExpr.ll	Fix SpeculativelyExecuteBB to either speculate all or none of the phis	2012-01-05 23:58:56 +00:00
2009-05-12-externweak.ll
2010-03-30-InvokeCrash.ll	Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID	2013-01-01 13:57:25 +00:00
2011-03-08-UnreachableUse.ll
2011-09-05-TrivialLPad.ll
basictest.ll
branch-cond-merge.ll
branch-cond-prop.ll
branch-fold-dbg.ll	Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID	2012-12-30 01:28:40 +00:00
branch-fold-test.ll
branch-fold.ll	Remove dyn_cast + dereference pattern by replacing it with a cast and changing	2012-06-24 10:15:42 +00:00
branch-phi-thread.ll	Fix the remaining TCL-style quotes found in the testsuite. This is	2012-07-02 19:09:46 +00:00
BrUnwind.ll	Fix the remaining TCL-style quotes found in the testsuite. This is	2012-07-02 19:09:46 +00:00
dbginfo.ll
dce-cond-after-folding-terminator.ll
DeadSetCC.ll	Fix the remaining TCL-style quotes found in the testsuite. This is	2012-07-02 19:09:46 +00:00
duplicate-phis.ll	Convert all tests using TCL-style quoting to use shell-style quoting.	2012-07-02 12:47:22 +00:00
EmptyBlockMerge.ll	Filecheckized 2x tests in SimplifyCFG and removed their date prefix to fit with current llvm style for test names.	2013-01-31 01:04:23 +00:00
EqualPHIEdgeBlockMerge.ll
ForwardSwitchConditionToPHI.ll
hoist-common-code.ll
hoist-dbgvalue.ll
HoistCode.ll
indirectbr.ll
invoke_unwind.ll
invoke.ll	fix PR13339 (remove the predecessor from the unwind BB when removing an invoke)	2012-07-16 22:49:40 +00:00
iterative-simplify.ll
lifetime.ll
lit.local.cfg	Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.	2012-02-16 06:28:33 +00:00
MagicPointer.ll
multiple-phis.ll	Fix SpeculativelyExecuteBB to either speculate all or none of the phis	2012-01-05 23:58:56 +00:00
noreturn-call.ll
phi-undef-loadstore.ll	SimplifyCFG: Enhance the "remove CFG edge that leads to null pointer dereference" optimization to also handle instructions with multiple uses.	2012-10-04 16:11:49 +00:00
PhiBlockMerge2.ll
PhiBlockMerge.ll
PhiEliminate2.ll
PhiEliminate3.ll
PhiEliminate.ll
PHINode.ll	Filecheckized 2x tests in SimplifyCFG and removed their date prefix to fit with current llvm style for test names.	2013-01-31 01:04:23 +00:00
PhiNoEliminate.ll
PR9946.ll	Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID	2013-01-01 13:57:25 +00:00
preserve-branchweights-partial.ll	Remove an incorrect assert during branch weight propagation.	2012-09-08 00:07:26 +00:00
preserve-branchweights-switch-create.ll	PGO: preserve branch-weight metadata when merging two switches where	2012-09-14 17:29:56 +00:00
preserve-branchweights.ll	PGO: preserve branch-weight metadata when simplifying Switch to a sub, an icmp	2012-09-18 00:47:33 +00:00
return-merge.ll
select-gep.ll	Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID	2012-12-30 01:28:40 +00:00
sink-common-code.ll	SimplifyCFG: sink common codes from IF, ELSE blocks down to END block.	2012-09-20 22:37:36 +00:00
speculate-store.ll	SimplifyCFG: If convert single conditional stores	2013-04-29 21:28:24 +00:00
speculate-with-offset.ll
SpeculativeExec.ll	Re-revert r173342, without losing the compile time improvements, flat	2013-01-27 06:42:03 +00:00
switch_create.ll	Only do switch-to-lookup table transformation when TargetTransformInfo	2012-11-07 21:35:12 +00:00
switch_switch_fold.ll
switch_thread.ll	Fix the remaining TCL-style quotes found in the testsuite. This is	2012-07-02 19:09:46 +00:00
switch-masked-bits.ll	Fix SpeculativelyExecuteBB to either speculate all or none of the phis	2012-01-05 23:58:56 +00:00
switch-on-const-select.ll	Use references to attribute groups on the call/invoke instructions.	2013-02-22 09:09:42 +00:00
switch-simplify-crash.ll
switch-to-icmp.ll	simplifycfg: Fix integer overflow converting switch into icmp.	2013-04-16 08:35:36 +00:00
trap-debugloc.ll
trapping-load-unreachable.ll
trivial-throw.ll	Don't remove a landing pad if the invoke requires a table entry.	2013-03-11 20:53:00 +00:00
two-entry-phi-return.ll
UncondBranchToReturn.ll	Fix the remaining TCL-style quotes found in the testsuite. This is	2012-07-02 19:09:46 +00:00
unreachable-blocks.ll	Make Value::isDereferenceablePointer() handle unreachable code blocks. (This	2012-01-23 00:05:17 +00:00
UnreachableEliminate.ll
volatile-phioper.ll	SimplifyCFG fix for volatile load/store.	2013-03-07 01:03:35 +00:00