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Start cleaning up the InlineCost class. This switches to sentinel values

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rather than a bitfield, a great suggestion by Chris during code review.

There is still quite a bit of cruft in the interface, but that requires
sorting out some awkward uses of the cost inside the actual inliner.

No functionality changed intended here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153853 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chandler Carruth 2012-04-01 22:44:09 +00:00
parent b66e943d4c
commit caa2c40a57
1 changed files with 20 additions and 25 deletions
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45
include/llvm/Analysis/InlineCost.h
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@ -49,59 +49,54 @@ namespace llvm {
/// directly tested to determine if inlining should occur given the cost and
/// threshold for this cost metric.
class InlineCost {
enum CostKind {
CK_Variable,
CK_Always,
CK_Never
enum SentinelValues {
AlwaysInlineCost = INT_MIN,
NeverInlineCost = INT_MAX
};
const int Cost : 30; // The inlining cost if neither always nor never.
const unsigned Kind : 2; // The type of cost, one of CostKind above.
/// \brief The estimated cost of inlining this callsite.
const int Cost;
/// \brief The adjusted threshold against which this cost should be tested.
/// \brief The adjusted threshold against which this cost was computed.
const int Threshold;
// Trivial constructor, interesting logic in the factory functions below.
InlineCost(int Cost, CostKind Kind, int Threshold)
: Cost(Cost), Kind(Kind), Threshold(Threshold) {}
InlineCost(int Cost, int Threshold)
: Cost(Cost), Threshold(Threshold) {}
public:
static InlineCost get(int Cost, int Threshold) {
InlineCost Result(Cost, CK_Variable, Threshold);
assert(Result.Cost == Cost && "Cost exceeds InlineCost precision");
return Result;
assert(Cost > AlwaysInlineCost && "Cost crosses sentinel value");
assert(Cost < NeverInlineCost && "Cost crosses sentinel value");
return InlineCost(Cost, Threshold);
}
static InlineCost getAlways() {
return InlineCost(0, CK_Always, 0);
return InlineCost(AlwaysInlineCost, 0);
}
static InlineCost getNever() {
return InlineCost(0, CK_Never, 0);
return InlineCost(NeverInlineCost, 0);
}
/// \brief Test whether the inline cost is low enough for inlining.
operator bool() const {
if (isAlways()) return true;
if (isNever()) return false;
return Cost < Threshold;
}
bool isVariable() const { return Kind == CK_Variable; }
bool isAlways() const { return Kind == CK_Always; }
bool isNever() const { return Kind == CK_Never; }
bool isAlways() const { return Cost == AlwaysInlineCost; }
bool isNever() const { return Cost == NeverInlineCost; }
bool isVariable() const { return !isAlways() && !isNever(); }
/// getCost() - Return a "variable" inline cost's amount. It is
/// an error to call this on an "always" or "never" InlineCost.
/// \brief Get the inline cost estimate.
/// It is an error to call this on an "always" or "never" InlineCost.
int getCost() const {
assert(Kind == CK_Variable && "Invalid access of InlineCost");
assert(isVariable() && "Invalid access of InlineCost");
return Cost;
}
/// \brief Get the cost delta from the threshold for inlining.
/// Only valid if the cost is of the variable kind. Returns a negative
/// value if the cost is too high to inline.
int getCostDelta() const {
return Threshold - getCost();
}
int getCostDelta() const { return Threshold - getCost(); }
};
/// InlineCostAnalyzer - Cost analyzer used by inliner.