[GlobalISel] NFCI, Getting GlobalISel ~5% faster

by replacing DenseMap with IndexedMap for LLTs within MRI, as
benchmarked by cross-compiling sqlite3 amalgamation for AArch64
on x86 machine.

Reviewed By: qcolombet

Differential Revision: https://reviews.llvm.org/D46809

llvm-svn: 333125

1 files changed, 4 insertions, 10 deletions

diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
index 544a4f1..6095bdd 100644
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -177,17 +177,13 @@ MachineRegisterInfo::createVirtualRegister(const TargetRegisterClass *RegClass,
   return Reg;
 }
 
-LLT MachineRegisterInfo::getType(unsigned VReg) const {
-  VRegToTypeMap::const_iterator TypeIt = getVRegToType().find(VReg);
-  return TypeIt != getVRegToType().end() ? TypeIt->second : LLT{};
-}
-
 void MachineRegisterInfo::setType(unsigned VReg, LLT Ty) {
   // Check that VReg doesn't have a class.
   assert((getRegClassOrRegBank(VReg).isNull() ||
          !getRegClassOrRegBank(VReg).is<const TargetRegisterClass *>()) &&
          "Can't set the size of a non-generic virtual register");
-  getVRegToType()[VReg] = Ty;
+  VRegToType.grow(VReg);
+  VRegToType[VReg] = Ty;
 }
 
 unsigned
@@ -196,15 +192,13 @@ MachineRegisterInfo::createGenericVirtualRegister(LLT Ty, StringRef Name) {
   unsigned Reg = createIncompleteVirtualRegister(Name);
   // FIXME: Should we use a dummy register class?
   VRegInfo[Reg].first = static_cast<RegisterBank *>(nullptr);
-  getVRegToType()[Reg] = Ty;
+  setType(Reg, Ty);
   if (TheDelegate)
     TheDelegate->MRI_NoteNewVirtualRegister(Reg);
   return Reg;
 }
 
-void MachineRegisterInfo::clearVirtRegTypes() {
-  getVRegToType().clear();
-}
+void MachineRegisterInfo::clearVirtRegTypes() { VRegToType.clear(); }
 
 /// clearVirtRegs - Remove all virtual registers (after physreg assignment).
 void MachineRegisterInfo::clearVirtRegs() {