[llvm] r226850 - Revert "Don't remove a landing pad if the invoke requires a table entry."

[Reid Kleckner]

Author: rnk
Date: Thu Jan 22 13:29:46 2015
New Revision: 226850

URL: http://llvm.org/viewvc/llvm-project?rev=226850&view=rev
Log:
Revert "Don't remove a landing pad if the invoke requires a table entry."

This reverts commit r176827.

Björn Steinbrink pointed out that this didn't actually fix the bug
(PR15555) it was attempting to fix.

With this reverted, we can now remove landingpad cleanups that
immediately resume unwinding, converting the invoke to a call.

Removed:
    llvm/trunk/test/Transforms/SimplifyCFG/trivial-throw.ll
Modified:
    llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=226850&r1=226849&r2=226850&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Thu Jan 22 13:29:46 2015
@@ -2949,20 +2949,9 @@ bool SimplifyCFGOpt::SimplifyResume(Resu
       return false;
 
   // Turn all invokes that unwind here into calls and delete the basic block.
-  bool InvokeRequiresTableEntry = false;
-  bool Changed = false;
   for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE;) {
     InvokeInst *II = cast<InvokeInst>((*PI++)->getTerminator());
-
-    if (II->hasFnAttr(Attribute::UWTable)) {
-      // Don't remove an `invoke' instruction if the ABI requires an entry into
-      // the table.
-      InvokeRequiresTableEntry = true;
-      continue;
-    }
-
     SmallVector<Value*, 8> Args(II->op_begin(), II->op_end() - 3);
-
     // Insert a call instruction before the invoke.
     CallInst *Call = CallInst::Create(II->getCalledValue(), Args, "", II);
     Call->takeName(II);
@@ -2982,14 +2971,11 @@ bool SimplifyCFGOpt::SimplifyResume(Resu
 
     // Finally, delete the invoke instruction!
     II->eraseFromParent();
-    Changed = true;
   }
 
-  if (!InvokeRequiresTableEntry)
-    // The landingpad is now unreachable.  Zap it.
-    BB->eraseFromParent();
-
-  return Changed;
+  // The landingpad is now unreachable.  Zap it.
+  BB->eraseFromParent();
+  return true;
 }
 
 bool SimplifyCFGOpt::SimplifyReturn(ReturnInst *RI, IRBuilder<> &Builder) {

Removed: llvm/trunk/test/Transforms/SimplifyCFG/trivial-throw.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/trivial-throw.ll?rev=226849&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/trivial-throw.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/trivial-throw.ll (removed)
@@ -1,77 +0,0 @@
-; RUN: opt -simplifycfg -S < %s | FileCheck %s
-; <rdar://problem/13360379>
-
- at _ZTVN10__cxxabiv117__class_type_infoE = external global i8*
- at _ZTS13TestException = linkonce_odr constant [16 x i8] c"13TestException\00"
- at _ZTI13TestException = linkonce_odr unnamed_addr constant { i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8** @_ZTVN10__cxxabiv117__class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([16 x i8]* @_ZTS13TestException, i32 0, i32 0) }
-
-define void @throw(i32 %n) #0 {
-entry:
-  %exception = call i8* @__cxa_allocate_exception(i64 1) #4
-  call void @__cxa_throw(i8* %exception, i8* bitcast ({ i8*, i8* }* @_ZTI13TestException to i8*), i8* null) #2
-  unreachable
-}
-
-define void @func() #0 {
-entry:
-; CHECK: func()
-; CHECK: invoke void @throw
-; CHECK-NOT: call void @throw
-  invoke void @throw(i32 42) #0
-          to label %exit unwind label %lpad
-
-lpad:
-  %tmp0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
-          cleanup
-  resume { i8*, i32 } %tmp0
-
-exit:
-  invoke void @abort() #2
-          to label %invoke.cont unwind label %lpad1
-
-invoke.cont:
-  unreachable
-
-lpad1:
-  %tmp1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
-          catch i8* bitcast ({ i8*, i8* }* @_ZTI13TestException to i8*)
-  %tmp2 = extractvalue { i8*, i32 } %tmp1, 1
-  %tmp3 = call i32 @llvm.eh.typeid.for(i8* bitcast ({ i8*, i8* }* @_ZTI13TestException to i8*)) #4
-  %matches = icmp eq i32 %tmp2, %tmp3
-  br i1 %matches, label %catch, label %eh.resume
-
-catch:
-  ret void
-
-eh.resume:
-  resume { i8*, i32 } %tmp1
-}
-
-define linkonce_odr hidden void @__clang_call_terminate(i8*) #1 {
-  %2 = call i8* @__cxa_begin_catch(i8* %0) #4
-  call void @_ZSt9terminatev() #5
-  unreachable
-}
-
-declare void @abort() #2
-
-declare i32 @llvm.eh.typeid.for(i8*) #3
-
-declare void @__cxa_end_catch()
-
-declare i8* @__cxa_allocate_exception(i64)
-
-declare i32 @__gxx_personality_v0(...)
-
-declare void @__cxa_throw(i8*, i8*, i8*)
-
-declare i8* @__cxa_begin_catch(i8*)
-
-declare void @_ZSt9terminatev()
-
-attributes #0 = { ssp uwtable }
-attributes #1 = { noinline noreturn nounwind }
-attributes #2 = { noreturn }
-attributes #3 = { nounwind readnone }
-attributes #4 = { nounwind }
-attributes #5 = { noreturn nounwind }