[llvm] 0c0c57f - Revert "[CodeGen] Postprocess PHI nodes for callbr"

[Bill Wendling via llvm-commits]

Author: Bill Wendling
Date: 2020-09-24T14:35:23-07:00
New Revision: 0c0c57f7b21bee1cda0fce83d9919a57764bd74e

URL: https://github.com/llvm/llvm-project/commit/0c0c57f7b21bee1cda0fce83d9919a57764bd74e
DIFF: https://github.com/llvm/llvm-project/commit/0c0c57f7b21bee1cda0fce83d9919a57764bd74e.diff

LOG: Revert "[CodeGen] Postprocess PHI nodes for callbr"

Accidental commit.

This reverts commit 7f4c940bd0b526f25e11c51bb4d58a85024330ae.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h

Removed: 
    llvm/test/CodeGen/X86/callbr-asm-phi-nodes.ll


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 8ef8ed9cae1c..dcfa6e405c74 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1084,8 +1084,9 @@ SDValue SelectionDAGBuilder::getControlRoot() {
 
 void SelectionDAGBuilder::visit(const Instruction &I) {
   // Set up outgoing PHI node register values before emitting the terminator.
-  if (I.isTerminator())
-    HandlePHINodesInSuccessorBlocks(I.getParent(), true);
+  if (I.isTerminator()) {
+    HandlePHINodesInSuccessorBlocks(I.getParent());
+  }
 
   // Increase the SDNodeOrder if dealing with a non-debug instruction.
   if (!isa<DbgInfoIntrinsic>(I))
@@ -2838,9 +2839,6 @@ void SelectionDAGBuilder::visitCallBr(const CallBrInst &I) {
   visitInlineAsm(I);
   CopyToExportRegsIfNeeded(&I);
 
-  // Set up outgoing PHI node register values before emitting the branch.
-  HandlePHINodesInSuccessorBlocks(I.getParent(), false);
-
   // Retrieve successors.
   MachineBasicBlock *Return = FuncInfo.MBBMap[I.getDefaultDest()];
 
@@ -9992,10 +9990,10 @@ void SelectionDAGISel::LowerArguments(const Function &F) {
 /// directly add them, because expansion might result in multiple MBB's for one
 /// BB.  As such, the start of the BB might correspond to a 
diff erent MBB than
 /// the end.
-void SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(
-    const BasicBlock *LLVMBB, bool Preprocess) {
+void
+SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) {
   const Instruction *TI = LLVMBB->getTerminator();
-  const CallBrInst *CI = dyn_cast<CallBrInst>(TI);
+
   SmallPtrSet<MachineBasicBlock *, 4> SuccsHandled;
 
   // Check PHI nodes in successors that expect a value to be available from this
@@ -10003,21 +10001,6 @@ void SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(
   for (unsigned succ = 0, e = TI->getNumSuccessors(); succ != e; ++succ) {
     const BasicBlock *SuccBB = TI->getSuccessor(succ);
     if (!isa<PHINode>(SuccBB->begin())) continue;
-
-    if (CI) {
-      if (Preprocess) {
-        // Don't push PHI node values back before an INLINEASM_BR instruction on
-        // the default branch.
-        if (SuccBB == CI->getDefaultDest())
-          continue;
-      } else {
-        // Don't push PHI node values back after an INLINEASM_BR instruction on
-        // the indirect branch.
-        if (SuccBB != CI->getDefaultDest())
-          continue;
-      }
-    }
-
     MachineBasicBlock *SuccMBB = FuncInfo.MBBMap[SuccBB];
 
     // If this terminator has multiple identical successors (common for

diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index 6e8ff1b7f161..4904134a7d40 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -783,8 +783,7 @@ class SelectionDAGBuilder {
   void processIntegerCallValue(const Instruction &I,
                                SDValue Value, bool IsSigned);
 
-  void HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB,
-                                       bool Preprocess);
+  void HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB);
 
   void emitInlineAsmError(const CallBase &Call, const Twine &Message);
 

diff  --git a/llvm/test/CodeGen/X86/callbr-asm-phi-nodes.ll b/llvm/test/CodeGen/X86/callbr-asm-phi-nodes.ll
deleted file mode 100644
index 3e5e5767afdd..000000000000
--- a/llvm/test/CodeGen/X86/callbr-asm-phi-nodes.ll
+++ /dev/null
@@ -1,28 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=i686-- -verify-machineinstrs < %s | FileCheck %s
-
- at var = global i32 0, align 4
-
-define i32 @test1() {
-; CHECK-LABEL: test1:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    #APP
-; CHECK-NEXT:    jmp .Ltmp0
-; CHECK-NEXT:    #NO_APP
-; CHECK-NEXT:    xorl %eax, %eax
-; CHECK-NEXT:  # %bb.2:
-; CHECK-NEXT:    retl
-; CHECK-NEXT:  .Ltmp0: # Block address taken
-; CHECK-NEXT:  .LBB0_1:
-; CHECK-NEXT:    movl $1, %eax
-; CHECK-NEXT:    retl
-  callbr void asm sideeffect "jmp ${1:l}", "*m,X,~{dirflag},~{fpsr},~{flags}"(i32* nonnull @var, i8* blockaddress(@test1, %1))
-          to label %2 [label %1]
-
-1:                                                ; preds = %0
-  br label %2
-
-2:                                                ; preds = %0, %1
-  %3 = phi i32 [ 1, %1 ], [ 0, %0 ]
-  ret i32 %3
-}