[PATCH] D126622: [X86][NFC] Refine X86 Domain Reassignment for compiling time

[Xiang Zhang via Phabricator via llvm-commits]

xiangzhangllvm created this revision.
Herald added subscribers: pengfei, hiraditya.
Herald added a project: All.
xiangzhangllvm requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

We encounter a special huge case which has huge number virtual register.
Such case cost quite long time to run this pass (X86 Domain Reassignment)
So refine the EnclosedEdges from set to bit vector to improve the building time.


https://reviews.llvm.org/D126622

Files:
  llvm/lib/Target/X86/X86DomainReassignment.cpp


Index: llvm/lib/Target/X86/X86DomainReassignment.cpp
===================================================================
--- llvm/lib/Target/X86/X86DomainReassignment.cpp
+++ llvm/lib/Target/X86/X86DomainReassignment.cpp
@@ -15,6 +15,7 @@
 #include "X86.h"
 #include "X86InstrInfo.h"
 #include "X86Subtarget.h"
+#include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/STLExtras.h"
@@ -374,7 +375,7 @@
   const X86InstrInfo *TII = nullptr;
 
   /// All edges that are included in some closure
-  DenseSet<unsigned> EnclosedEdges;
+  BitVector EnclosedEdges{8, false};
 
   /// All instructions that are included in some closure.
   DenseMap<MachineInstr *, unsigned> EnclosedInstrs;
@@ -429,10 +430,10 @@
 void X86DomainReassignment::visitRegister(Closure &C, Register Reg,
                                           RegDomain &Domain,
                                           SmallVectorImpl<unsigned> &Worklist) {
-  if (EnclosedEdges.count(Reg))
+  if (!Reg.isVirtual())
     return;
 
-  if (!Reg.isVirtual())
+  if (EnclosedEdges.test(Register::virtReg2Index(Reg)))
     return;
 
   if (!MRI->hasOneDef(Reg))
@@ -550,7 +551,7 @@
     // Register already in this closure.
     if (!C.insertEdge(CurReg))
       continue;
-    EnclosedEdges.insert(Reg);
+    EnclosedEdges.set(Register::virtReg2Index(Reg));
 
     MachineInstr *DefMI = MRI->getVRegDef(CurReg);
     encloseInstr(C, DefMI);
@@ -742,6 +743,7 @@
   bool Changed = false;
 
   EnclosedEdges.clear();
+  EnclosedEdges.resize(MRI->getNumVirtRegs());
   EnclosedInstrs.clear();
 
   std::vector<Closure> Closures;
@@ -756,7 +758,7 @@
       continue;
 
     // Register already in closure.
-    if (EnclosedEdges.count(Reg))
+    if (EnclosedEdges.test(Idx))
       continue;
 
     // Calculate closure starting with Reg.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D126622.432810.patch
Type: text/x-patch
Size: 1853 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220530/e1b9a108/attachment.bin>