Introduce @llvm.experimental.deoptimize
Summary:
This intrinsic, together with deoptimization operand bundles, allow
frontends to express transfer of control and frame-local state from
one (typically more specialized, hence faster) version of a function
into another (typically more generic, hence slower) version.
In languages with a fully integrated managed runtime this intrinsic can
be used to implement "uncommon trap" like functionality. In unmanaged
languages like C and C++, this intrinsic can be used to represent the
slow paths of specialized functions.
Note: this change does not address how `@llvm.experimental_deoptimize`
is lowered. That will be done in a later change.
Reviewers: chandlerc, rnk, atrick, reames
Subscribers: llvm-commits, kmod, mjacob, maksfb, mcrosier, JosephTremoulet
Differential Revision: http://reviews.llvm.org/D17732
llvm-svn: 263281
diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index 89a1d74..9f806fa 100644
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -162,6 +162,21 @@
return nullptr;
}
+CallInst *BasicBlock::getTerminatingDeoptimizeCall() {
+ if (InstList.empty())
+ return nullptr;
+ auto *RI = dyn_cast<ReturnInst>(&InstList.back());
+ if (!RI || RI == &InstList.front())
+ return nullptr;
+
+ if (auto *CI = dyn_cast_or_null<CallInst>(RI->getPrevNode()))
+ if (Function *F = CI->getCalledFunction())
+ if (F->getIntrinsicID() == Intrinsic::experimental_deoptimize)
+ return CI;
+
+ return nullptr;
+}
+
Instruction* BasicBlock::getFirstNonPHI() {
for (Instruction &I : *this)
if (!isa<PHINode>(I))