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authorDerek Schuff <dschuff@chromium.org>2013-01-09 16:55:43 -0800
committerDerek Schuff <dschuff@chromium.org>2013-01-11 13:47:37 -0800
commitb770d0e0636a4b5ad61b1ca661caee67576c05fc (patch)
treec486ce032d41f97313c50629bd5b879f53e6ccbf /lib/Transforms/Utils/SimplifyCFG.cpp
parentb835840cf112a6178506d834b58aa625f59a8994 (diff)
parent1ad9253c9d34ccbce3e7e4ea5d87c266cbf93410 (diff)
Merge commit '1ad9253c9d34ccbce3e7e4ea5d87c266cbf93410'
deplib features commented out due to removal upstream; will add back as a localmod Conflicts: include/llvm/ADT/Triple.h include/llvm/MC/MCAssembler.h include/llvm/Target/TargetFrameLowering.h lib/CodeGen/AsmPrinter/DwarfDebug.cpp lib/CodeGen/AsmPrinter/DwarfDebug.h lib/CodeGen/BranchFolding.cpp lib/LLVMBuild.txt lib/Linker/LinkArchives.cpp lib/MC/MCAssembler.cpp lib/MC/MCELFStreamer.cpp lib/Makefile lib/Target/ARM/ARMExpandPseudoInsts.cpp lib/Target/ARM/ARMFrameLowering.cpp lib/Target/ARM/ARMISelLowering.cpp lib/Target/ARM/ARMSubtarget.h lib/Target/ARM/ARMTargetObjectFile.cpp lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp lib/Target/Mips/MipsInstrFPU.td lib/Target/Mips/MipsInstrInfo.td lib/Target/X86/X86CodeEmitter.cpp lib/Target/X86/X86Subtarget.h lib/VMCore/Module.cpp test/MC/MachO/ARM/nop-armv4-padding.s tools/Makefile tools/llc/llc.cpp tools/lto/LTOModule.cpp tools/lto/lto.cpp
Diffstat (limited to 'lib/Transforms/Utils/SimplifyCFG.cpp')
-rw-r--r--lib/Transforms/Utils/SimplifyCFG.cpp62
1 files changed, 42 insertions, 20 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 6c34eed13d..3cae77227c 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -13,6 +13,14 @@
#define DEBUG_TYPE "simplifycfg"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Constants.h"
#include "llvm/DataLayout.h"
#include "llvm/DerivedTypes.h"
@@ -25,15 +33,6 @@
#include "llvm/Metadata.h"
#include "llvm/Module.h"
#include "llvm/Operator.h"
-#include "llvm/Type.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ConstantRange.h"
@@ -42,9 +41,10 @@
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetTransformInfo.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Type.h"
#include <algorithm>
-#include <set>
#include <map>
+#include <set>
using namespace llvm;
static cl::opt<unsigned>
@@ -3511,22 +3511,44 @@ bool SwitchLookupTable::WouldFitInRegister(const DataLayout *TD,
static bool ShouldBuildLookupTable(SwitchInst *SI,
uint64_t TableSize,
const DataLayout *TD,
+ const TargetTransformInfo *TTI,
const SmallDenseMap<PHINode*, Type*>& ResultTypes) {
- // The table density should be at least 40%. This is the same criterion as for
- // jump tables, see SelectionDAGBuilder::handleJTSwitchCase.
- // FIXME: Find the best cut-off.
if (SI->getNumCases() > TableSize || TableSize >= UINT64_MAX / 10)
return false; // TableSize overflowed, or mul below might overflow.
- if (SI->getNumCases() * 10 >= TableSize * 4)
- return true;
- // If each table would fit in a register, we should build it anyway.
+ bool AllTablesFitInRegister = true;
+ bool HasIllegalType = false;
for (SmallDenseMap<PHINode*, Type*>::const_iterator I = ResultTypes.begin(),
E = ResultTypes.end(); I != E; ++I) {
- if (!SwitchLookupTable::WouldFitInRegister(TD, TableSize, I->second))
- return false;
+ Type *Ty = I->second;
+
+ // Saturate this flag to true.
+ HasIllegalType = HasIllegalType ||
+ !TTI->getScalarTargetTransformInfo()->isTypeLegal(Ty);
+
+ // Saturate this flag to false.
+ AllTablesFitInRegister = AllTablesFitInRegister &&
+ SwitchLookupTable::WouldFitInRegister(TD, TableSize, Ty);
+
+ // If both flags saturate, we're done. NOTE: This *only* works with
+ // saturating flags, and all flags have to saturate first due to the
+ // non-deterministic behavior of iterating over a dense map.
+ if (HasIllegalType && !AllTablesFitInRegister)
+ break;
}
- return true;
+
+ // If each table would fit in a register, we should build it anyway.
+ if (AllTablesFitInRegister)
+ return true;
+
+ // Don't build a table that doesn't fit in-register if it has illegal types.
+ if (HasIllegalType)
+ return false;
+
+ // The table density should be at least 40%. This is the same criterion as for
+ // jump tables, see SelectionDAGBuilder::handleJTSwitchCase.
+ // FIXME: Find the best cut-off.
+ return SI->getNumCases() * 10 >= TableSize * 4;
}
/// SwitchToLookupTable - If the switch is only used to initialize one or more
@@ -3607,7 +3629,7 @@ static bool SwitchToLookupTable(SwitchInst *SI,
APInt RangeSpread = MaxCaseVal->getValue() - MinCaseVal->getValue();
uint64_t TableSize = RangeSpread.getLimitedValue() + 1;
- if (!ShouldBuildLookupTable(SI, TableSize, TD, ResultTypes))
+ if (!ShouldBuildLookupTable(SI, TableSize, TD, TTI, ResultTypes))
return false;
// Create the BB that does the lookups.