[PATCH] D111223: [GlobalISel] Simplify RegBankSelect

[Sebastian Neubauer via Phabricator via llvm-commits]

sebastian-ne updated this revision to Diff 381968.
sebastian-ne marked an inline comment as done.
sebastian-ne added a comment.

Use pop_back_val


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111223/new/

https://reviews.llvm.org/D111223

Files:
  llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp


Index: llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp
+++ llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp
@@ -699,11 +699,12 @@
     // Set a sensible insertion point so that subsequent calls to
     // MIRBuilder.
     MIRBuilder.setMBB(*MBB);
-    for (MachineBasicBlock::iterator MII = MBB->begin(), End = MBB->end();
-         MII != End;) {
-      // MI might be invalidated by the assignment, so move the
-      // iterator before hand.
-      MachineInstr &MI = *MII++;
+    SmallVector<MachineInstr *> WorkList;
+    for (MachineInstr &MI : reverse(MBB->instrs()))
+      WorkList.push_back(&MI);
+
+    while (!WorkList.empty()) {
+      MachineInstr &MI = *WorkList.pop_back_val();
 
       // Ignore target-specific post-isel instructions: they should use proper
       // regclasses.
@@ -728,18 +729,6 @@
                            "unable to map instruction", MI);
         return false;
       }
-
-      // It's possible the mapping changed control flow, and moved the following
-      // instruction to a new block, so figure out the new parent.
-      if (MII != End) {
-        MachineBasicBlock *NextInstBB = MII->getParent();
-        if (NextInstBB != MBB) {
-          LLVM_DEBUG(dbgs() << "Instruction mapping changed control flow\n");
-          MBB = NextInstBB;
-          MIRBuilder.setMBB(*MBB);
-          End = MBB->end();
-        }
-      }
     }
   }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D111223.381968.patch
Type: text/x-patch
Size: 1503 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20211025/0fe76b64/attachment.bin>