Update LLVM for 3.5 rebase (r209712).
Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/lib/CodeGen/SpillPlacement.cpp b/lib/CodeGen/SpillPlacement.cpp
index 5f73469..24e94d1 100644
--- a/lib/CodeGen/SpillPlacement.cpp
+++ b/lib/CodeGen/SpillPlacement.cpp
@@ -27,7 +27,6 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "spillplacement"
#include "SpillPlacement.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/CodeGen/EdgeBundles.h"
@@ -41,6 +40,8 @@
using namespace llvm;
+#define DEBUG_TYPE "spillplacement"
+
char SpillPlacement::ID = 0;
INITIALIZE_PASS_BEGIN(SpillPlacement, "spill-code-placement",
"Spill Code Placement Analysis", true, true)
@@ -59,9 +60,26 @@
MachineFunctionPass::getAnalysisUsage(AU);
}
+namespace {
+static BlockFrequency Threshold;
+}
+
/// Decision threshold. A node gets the output value 0 if the weighted sum of
/// its inputs falls in the open interval (-Threshold;Threshold).
-static const BlockFrequency Threshold = 2;
+static BlockFrequency getThreshold() { return Threshold; }
+
+/// \brief Set the threshold for a given entry frequency.
+///
+/// Set the threshold relative to \c Entry. Since the threshold is used as a
+/// bound on the open interval (-Threshold;Threshold), 1 is the minimum
+/// threshold.
+static void setThreshold(const BlockFrequency &Entry) {
+ // Apparently 2 is a good threshold when Entry==2^14, but we need to scale
+ // it. Divide by 2^13, rounding as appropriate.
+ uint64_t Freq = Entry.getFrequency();
+ uint64_t Scaled = (Freq >> 13) + bool(Freq & (1 << 12));
+ Threshold = std::max(UINT64_C(1), Scaled);
+}
/// Node - Each edge bundle corresponds to a Hopfield node.
///
@@ -110,7 +128,7 @@
// the CFG.
void clear() {
BiasN = BiasP = Value = 0;
- SumLinkWeights = Threshold;
+ SumLinkWeights = getThreshold();
Links.clear();
}
@@ -168,9 +186,9 @@
// 2. It helps tame rounding errors when the links nominally sum to 0.
//
bool Before = preferReg();
- if (SumN >= SumP + Threshold)
+ if (SumN >= SumP + getThreshold())
Value = -1;
- else if (SumP >= SumN + Threshold)
+ else if (SumP >= SumN + getThreshold())
Value = 1;
else
Value = 0;
@@ -189,6 +207,7 @@
// Compute total ingoing and outgoing block frequencies for all bundles.
BlockFrequencies.resize(mf.getNumBlockIDs());
MBFI = &getAnalysis<MachineBlockFrequencyInfo>();
+ setThreshold(MBFI->getEntryFreq());
for (MachineFunction::iterator I = mf.begin(), E = mf.end(); I != E; ++I) {
unsigned Num = I->getNumber();
BlockFrequencies[Num] = MBFI->getBlockFreq(I);
@@ -200,7 +219,7 @@
void SpillPlacement::releaseMemory() {
delete[] nodes;
- nodes = 0;
+ nodes = nullptr;
}
/// activate - mark node n as active if it wasn't already.
@@ -375,6 +394,6 @@
ActiveNodes->reset(n);
Perfect = false;
}
- ActiveNodes = 0;
+ ActiveNodes = nullptr;
return Perfect;
}