Add a new function attribute 'cold' to functions.
Other than recognizing the attribute, the patch does little else.
It changes the branch probability analyzer so that edges into
blocks postdominated by a cold function are given low weight.
Added analysis and code generation tests. Added documentation for the
new attribute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182638 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index 4fe6f9d..e48ebb1 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -217,6 +217,8 @@
return "uwtable";
if (hasAttribute(Attribute::ZExt))
return "zeroext";
+ if (hasAttribute(Attribute::Cold))
+ return "cold";
// FIXME: These should be output like this:
//
@@ -396,6 +398,7 @@
case Attribute::SanitizeMemory: return 1ULL << 37;
case Attribute::NoBuiltin: return 1ULL << 38;
case Attribute::Returned: return 1ULL << 39;
+ case Attribute::Cold: return 1ULL << 40;
}
llvm_unreachable("Unsupported attribute type");
}
diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp
index d106173..a94c156 100644
--- a/lib/IR/Verifier.cpp
+++ b/lib/IR/Verifier.cpp
@@ -692,7 +692,8 @@
I->getKindAsEnum() == Attribute::SanitizeMemory ||
I->getKindAsEnum() == Attribute::MinSize ||
I->getKindAsEnum() == Attribute::NoDuplicate ||
- I->getKindAsEnum() == Attribute::NoBuiltin) {
+ I->getKindAsEnum() == Attribute::NoBuiltin ||
+ I->getKindAsEnum() == Attribute::Cold) {
if (!isFunction)
CheckFailed("Attribute '" + I->getKindAsString() +
"' only applies to functions!", V);