Introduce a @llvm.experimental.guard intrinsic

Summary:
As discussed on llvm-dev[1].

This change adds the basic boilerplate code around having this intrinsic
in LLVM:

 - Changes in Intrinsics.td, and the IR Verifier
 - A lowering pass to lower @llvm.experimental.guard to normal
   control flow
 - Inliner support

[1]: http://lists.llvm.org/pipermail/llvm-dev/2016-February/095523.html

Reviewers: reames, atrick, chandlerc, rnk, JosephTremoulet, echristo

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18527

llvm-svn: 264976

3 files changed, 11 insertions, 0 deletions

diff --git a/llvm/include/llvm/IR/Intrinsics.td b/llvm/include/llvm/IR/Intrinsics.td
index 5f3c7e3ef40..b056cdbb6ca 100644
--- a/llvm/include/llvm/IR/Intrinsics.td
+++ b/llvm/include/llvm/IR/Intrinsics.td
@@ -597,6 +597,10 @@ def int_debugtrap : Intrinsic<[]>,
 def int_experimental_deoptimize : Intrinsic<[llvm_any_ty], [llvm_vararg_ty],
                                             [Throws]>;
 
+// Support for speculative runtime guards
+def int_experimental_guard : Intrinsic<[], [llvm_i1_ty, llvm_vararg_ty],
+                                       [Throws]>;
+
 // NOP: calls/invokes to this intrinsic are removed by codegen
 def int_donothing : Intrinsic<[], [], [IntrNoMem]>;
 
diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
index 16f978ae72f..125d2a19318 100644
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -188,6 +188,7 @@ void initializeLoopIdiomRecognizePass(PassRegistry&);
 void initializeLowerAtomicPass(PassRegistry&);
 void initializeLowerBitSetsPass(PassRegistry&);
 void initializeLowerExpectIntrinsicPass(PassRegistry&);
+void initializeLowerGuardIntrinsicPass(PassRegistry&);
 void initializeLowerIntrinsicsPass(PassRegistry&);
 void initializeLowerInvokePass(PassRegistry&);
 void initializeLowerSwitchPass(PassRegistry&);
diff --git a/llvm/include/llvm/Transforms/Scalar.h b/llvm/include/llvm/Transforms/Scalar.h
index 6117c05e556..c2bd77c1277 100644
--- a/llvm/include/llvm/Transforms/Scalar.h
+++ b/llvm/include/llvm/Transforms/Scalar.h
@@ -374,6 +374,12 @@ Pass *createLowerAtomicPass();
 
 //===----------------------------------------------------------------------===//
 //
+// LowerGuardIntrinsic - Lower guard intrinsics to normal control flow.
+//
+Pass *createLowerGuardIntrinsicPass();
+
+//===----------------------------------------------------------------------===//
+//
 // ValuePropagation - Propagate CFG-derived value information
 //
 Pass *createCorrelatedValuePropagationPass();