Update LLVM for 3.5 rebase (r209712).
Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/lib/CodeGen/CalcSpillWeights.cpp b/lib/CodeGen/CalcSpillWeights.cpp
index 4833731..bc033f9 100644
--- a/lib/CodeGen/CalcSpillWeights.cpp
+++ b/lib/CodeGen/CalcSpillWeights.cpp
@@ -7,8 +7,6 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "calcspillweights"
-
#include "llvm/CodeGen/CalcSpillWeights.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
@@ -22,6 +20,8 @@
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
+#define DEBUG_TYPE "calcspillweights"
+
void llvm::calculateSpillWeightsAndHints(LiveIntervals &LIS,
MachineFunction &MF,
const MachineLoopInfo &MLI,
@@ -96,8 +96,8 @@
VirtRegAuxInfo::calculateSpillWeightAndHint(LiveInterval &li) {
MachineRegisterInfo &mri = MF.getRegInfo();
const TargetRegisterInfo &tri = *MF.getTarget().getRegisterInfo();
- MachineBasicBlock *mbb = 0;
- MachineLoop *loop = 0;
+ MachineBasicBlock *mbb = nullptr;
+ MachineLoop *loop = nullptr;
bool isExiting = false;
float totalWeight = 0;
SmallPtrSet<MachineInstr*, 8> visited;
@@ -149,7 +149,11 @@
unsigned hint = copyHint(mi, li.reg, tri, mri);
if (!hint)
continue;
- float hweight = Hint[hint] += weight;
+ // Force hweight onto the stack so that x86 doesn't add hidden precision,
+ // making the comparison incorrectly pass (i.e., 1 > 1 == true??).
+ //
+ // FIXME: we probably shouldn't use floats at all.
+ volatile float hweight = Hint[hint] += weight;
if (TargetRegisterInfo::isPhysicalRegister(hint)) {
if (hweight > bestPhys && mri.isAllocatable(hint))
bestPhys = hweight, hintPhys = hint;