Revert "Allow output constraints on "asm goto""

This reverts commit 52366088a8e42c2f1e96e8430b84b8b65ec3f7bc.

I accidentally pushed this before supporting changes.

5 files changed, 18 insertions, 50 deletions

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 731c1cea0dc..1a17f633ae1 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -6419,6 +6419,9 @@ bool LLParser::ParseCallBr(Instruction *&Inst, PerFunctionState &PFS) {
                           /*IsCall=*/true))
     return true;
 
+  if (isa<InlineAsm>(Callee) && !Ty->getReturnType()->isVoidTy())
+    return Error(RetTypeLoc, "asm-goto outputs not supported");
+
   // Set up the Attribute for the function.
   SmallVector<Value *, 8> Args;
   SmallVector<AttributeSet, 8> ArgAttrs;
diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index 8928dc858d5..f433c4b6c90 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -1109,17 +1109,6 @@ bool MachineBasicBlock::canSplitCriticalEdge(
   if (Succ->isEHPad())
     return false;
 
-  // Splitting the critical edge to a callbr's indirect block isn't advised.
-  // Don't do it in this generic function.
-  if (Succ->hasAddressTaken())
-    if (auto *cbr = dyn_cast<CallBrInst>(getBasicBlock()->getTerminator()))
-      if (auto *bb = Succ->getBasicBlock())
-        if (cbr->getDefaultDest() != bb)
-          if (llvm::any_of(cbr->getIndirectDests(), [&](const BasicBlock *succ){
-                  return succ == bb;
-              }))
-            return false;
-
   const MachineFunction *MF = getParent();
 
   // Performance might be harmed on HW that implements branching using exec mask
diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index cbafd387a62..ca57e51268e 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -633,30 +633,17 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
   }
 
   // Count the number of landing pad successors.
-  SmallPtrSet<const MachineBasicBlock*, 4> LandingPadSuccs;
-  for (const auto *succ : MBB->successors()) {
-    if (succ->isEHPad())
-      LandingPadSuccs.insert(succ);
-    if (!FunctionBlocks.count(succ))
-      report("MBB has successor that isn't part of the function.", MBB);
-    if (!MBBInfoMap[succ].Preds.count(MBB)) {
-      report("Inconsistent CFG", MBB);
-      errs() << "MBB is not in the predecessor list of the successor "
-             << printMBBReference(*succ) << ".\n";
-    }
-  }
-
-  // Count the number of INLINEASM_BR indirect pad successors.
-  SmallPtrSet<const MachineBasicBlock*, 4> IndirectPadSuccs;
-  for (const auto *succ : MBB->successors()) {
-    if (succ->isInlineAsmBrIndirectPad())
-      IndirectPadSuccs.insert(succ);
-    if (!FunctionBlocks.count(succ))
+  SmallPtrSet<MachineBasicBlock*, 4> LandingPadSuccs;
+  for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
+       E = MBB->succ_end(); I != E; ++I) {
+    if ((*I)->isEHPad())
+      LandingPadSuccs.insert(*I);
+    if (!FunctionBlocks.count(*I))
       report("MBB has successor that isn't part of the function.", MBB);
-    if (!MBBInfoMap[succ].Preds.count(MBB)) {
+    if (!MBBInfoMap[*I].Preds.count(MBB)) {
       report("Inconsistent CFG", MBB);
       errs() << "MBB is not in the predecessor list of the successor "
-             << printMBBReference(*succ) << ".\n";
+             << printMBBReference(*(*I)) << ".\n";
     }
   }
 
@@ -697,13 +684,11 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
         // It's possible that the block legitimately ends with a noreturn
         // call or an unreachable, in which case it won't actually fall
         // out the bottom of the function.
-      } else if (MBB->succ_size() == LandingPadSuccs.size() ||
-                 MBB->succ_size() == IndirectPadSuccs.size()) {
+      } else if (MBB->succ_size() == LandingPadSuccs.size()) {
         // It's possible that the block legitimately ends with a noreturn
         // call or an unreachable, in which case it won't actually fall
         // out of the block.
-      } else if (MBB->succ_size() != 1 + LandingPadSuccs.size() &&
-                 MBB->succ_size() != 1 + IndirectPadSuccs.size()) {
+      } else if (MBB->succ_size() != 1+LandingPadSuccs.size()) {
         report("MBB exits via unconditional fall-through but doesn't have "
                "exactly one CFG successor!", MBB);
       } else if (!MBB->isSuccessor(&*MBBI)) {
@@ -725,10 +710,7 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
       // landingpad, accept it as valid control flow.
       if (MBB->succ_size() != 1+LandingPadSuccs.size() &&
           (MBB->succ_size() != 1 || LandingPadSuccs.size() != 1 ||
-           *MBB->succ_begin() != *LandingPadSuccs.begin()) &&
-          MBB->succ_size() != 1 + IndirectPadSuccs.size() &&
-          (MBB->succ_size() != 1 || IndirectPadSuccs.size() != 1 ||
-           *MBB->succ_begin() != *IndirectPadSuccs.begin())) {
+           *MBB->succ_begin() != *LandingPadSuccs.begin())) {
         report("MBB exits via unconditional branch but doesn't have "
                "exactly one CFG successor!", MBB);
       } else if (!MBB->isSuccessor(TBB)) {
@@ -858,14 +840,8 @@ void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) {
     if (!FirstTerminator)
       FirstTerminator = MI;
   } else if (FirstTerminator && !MI->isDebugEntryValue()) {
-    // An "INLINEASM_BR" will fallthrough to the successor block executing any
-    // "COPY" instructions that exist so that they can be assigned in the
-    // fallthrough block..
-    if (FirstTerminator->getOpcode() != TargetOpcode::INLINEASM_BR ||
-        MI->getOpcode() != TargetOpcode::COPY) {
-      report("Non-terminator instruction after the first terminator", MI);
-      errs() << "First terminator was:\t" << *FirstTerminator;
-    }
+    report("Non-terminator instruction after the first terminator", MI);
+    errs() << "First terminator was:\t" << *FirstTerminator;
   }
 }
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 1505506dbf0..00b05c5db2f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2847,7 +2847,6 @@ void SelectionDAGBuilder::visitCallBr(const CallBrInst &I) {
   assert(isa<InlineAsm>(I.getCalledValue()) &&
          "Only know how to handle inlineasm callbr");
   visitInlineAsm(&I);
-  CopyToExportRegsIfNeeded(&I);
 
   // Retrieve successors.
   MachineBasicBlock *Return = FuncInfo.MBBMap[I.getDefaultDest()];
@@ -2857,7 +2856,6 @@ void SelectionDAGBuilder::visitCallBr(const CallBrInst &I) {
   for (unsigned i = 0, e = I.getNumIndirectDests(); i < e; ++i) {
     MachineBasicBlock *Target = FuncInfo.MBBMap[I.getIndirectDest(i)];
     addSuccessorWithProb(CallBrMBB, Target);
-    Target->setIsInlineAsmBrIndirectPad();
   }
   CallBrMBB->normalizeSuccProbs();
 
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 184a9a0569b..e3a3d91b455 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2501,6 +2501,8 @@ void Verifier::visitIndirectBrInst(IndirectBrInst &BI) {
 void Verifier::visitCallBrInst(CallBrInst &CBI) {
   Assert(CBI.isInlineAsm(), "Callbr is currently only used for asm-goto!",
          &CBI);
+  Assert(CBI.getType()->isVoidTy(), "Callbr return value is not supported!",
+         &CBI);
   for (unsigned i = 0, e = CBI.getNumSuccessors(); i != e; ++i)
     Assert(CBI.getSuccessor(i)->getType()->isLabelTy(),
            "Callbr successors must all have pointer type!", &CBI);