Add the 'resume' instruction for the new EH rewrite.

This adds the 'resume' instruction class, IR parsing, and bitcode reading and
writing. The 'resume' instruction resumes propagation of an existing (in-flight)
exception whose unwinding was interrupted with a 'landingpad' instruction (to be
added later).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136589 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 7 insertions, 4 deletions

diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 0283568..771a50b 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -2506,7 +2506,7 @@ static bool EvaluateFunction(Function *F, Constant *&RetVal,
         CallStack.pop_back();  // return from fn.
         return true;  // We succeeded at evaluating this ctor!
       } else {
-        // invoke, unwind, unreachable.
+        // invoke, unwind, resume, unreachable.
         return false;  // Cannot handle this terminator.
       }
 
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index c33dec1..09edc41 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -732,9 +732,11 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
       }
     }
     
-    // If the stack restore is in a return/unwind block and if there are no
-    // allocas or calls between the restore and the return, nuke the restore.
-    if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI)))
+    // If the stack restore is in a return, resume, or unwind block and if there
+    // are no allocas or calls between the restore and the return, nuke the
+    // restore.
+    if (!CannotRemove && (isa<ReturnInst>(TI) || isa<ResumeInst>(TI) ||
+                          isa<UnwindInst>(TI)))
       return EraseInstFromFunction(CI);
     break;
   }
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 749ba40..4e1c274 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -528,6 +528,7 @@ private:
     visitTerminatorInst(II);
   }
   void visitCallSite      (CallSite CS);
+  void visitResumeInst    (TerminatorInst &I) { /*returns void*/ }
   void visitUnwindInst    (TerminatorInst &I) { /*returns void*/ }
   void visitUnreachableInst(TerminatorInst &I) { /*returns void*/ }
   void visitFenceInst     (FenceInst &I) { /*returns void*/ }