Fix - CodeExtractor : Inherit Target Dependent Attributes from the parent function.
When extracting a set of blocks make sure to inherit all of the target
dependent attributes to make sure that the function will be valid for
lowering. One example is the "target-features" attribute for x86, if the
extracted region has functionality that relies on a specific feature it
will fail to be lowered.
This also allows for extracted functions to be valid for inlining, at
least back into the parent function, as the target attributes are tested
when inlining for compatibility.
Patch by River Riddle!
Differential Revision: https://reviews.llvm.org/D22713
llvm-svn: 277315
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
index 6816eb4..c514c9c 100644
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -351,7 +351,22 @@
// If the old function is no-throw, so is the new one.
if (oldFunction->doesNotThrow())
newFunction->setDoesNotThrow();
-
+
+ // Inherit the uwtable attribute if we need to.
+ if (oldFunction->hasUWTable())
+ newFunction->setHasUWTable();
+
+ // Inherit all of the target dependent attributes.
+ // (e.g. If the extracted region contains a call to an x86.sse
+ // instruction we need to make sure that the extracted region has the
+ // "target-features" attribute allowing it to be lowered.
+ // FIXME: This should be changed to check to see if a specific
+ // attribute can not be inherited.
+ AttributeSet OldFnAttrs = oldFunction->getAttributes().getFnAttributes();
+ AttrBuilder AB(OldFnAttrs, AttributeSet::FunctionIndex);
+ for (auto Attr : AB.td_attrs())
+ newFunction->addFnAttr(Attr.first, Attr.second);
+
newFunction->getBasicBlockList().push_back(newRootNode);
// Create an iterator to name all of the arguments we inserted.