From f4d25a2c461f7a64fcc643a6ea2541e87067d036 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@gmail.com>
Date: Sun, 30 Sep 2012 19:49:56 +0000
Subject: [PATCH] Change getX86SubSuperRegister to take an MVT::SimpleValueType
 rather than an EVT and add llvm_unreachable to the switches. Helps it compile
 to dramatically better code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164919 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86AsmPrinter.cpp   |  2 +-
 lib/Target/X86/X86ISelLowering.cpp |  2 +-
 lib/Target/X86/X86RegisterInfo.cpp | 15 ++++++++-------
 lib/Target/X86/X86RegisterInfo.h   |  4 ++--
 4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/lib/Target/X86/X86AsmPrinter.cpp b/lib/Target/X86/X86AsmPrinter.cpp
index 33ab5675b5f..2fc83a2df71 100644
--- a/lib/Target/X86/X86AsmPrinter.cpp
+++ b/lib/Target/X86/X86AsmPrinter.cpp
@@ -243,7 +243,7 @@ void X86AsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
     if (AsmVariant == 0) O << '%';
     unsigned Reg = MO.getReg();
     if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
-      EVT VT = (strcmp(Modifier+6,"64") == 0) ?
+      MVT::SimpleValueType VT = (strcmp(Modifier+6,"64") == 0) ?
         MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
                     ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
       Reg = getX86SubSuperRegister(Reg, VT);
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index bc8f8f46d40..7a87349a2d1 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -12110,7 +12110,7 @@ X86TargetLowering::EmitAtomicLoadArith(MachineInstr *MI,
   SrcReg = MI->getOperand(CurOp++).getReg();
 
   const TargetRegisterClass *RC = MRI.getRegClass(DstReg);
-  EVT VT = *RC->vt_begin();
+  MVT::SimpleValueType VT = *RC->vt_begin();
   unsigned AccPhyReg = getX86SubSuperRegister(X86::EAX, VT);
 
   unsigned LCMPXCHGOpc = getCmpXChgOpcode(VT);
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 1424f221d75..6f18be3042b 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -590,9 +590,10 @@ unsigned X86RegisterInfo::getEHHandlerRegister() const {
 }
 
 namespace llvm {
-unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
-  switch (VT.getSimpleVT().SimpleTy) {
-  default: return Reg;
+unsigned getX86SubSuperRegister(unsigned Reg, MVT::SimpleValueType VT,
+                                bool High) {
+  switch (VT) {
+  default: llvm_unreachable("Unexpected VT");
   case MVT::i8:
     if (High) {
       switch (Reg) {
@@ -608,7 +609,7 @@ unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
       }
     } else {
       switch (Reg) {
-      default: return 0;
+      default: llvm_unreachable("Unexpected register");
       case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
         return X86::AL;
       case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
@@ -645,7 +646,7 @@ unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
     }
   case MVT::i16:
     switch (Reg) {
-    default: return Reg;
+    default: llvm_unreachable("Unexpected register");
     case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
       return X86::AX;
     case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
@@ -681,7 +682,7 @@ unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
     }
   case MVT::i32:
     switch (Reg) {
-    default: return Reg;
+    default: llvm_unreachable("Unexpected register");
     case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
       return X86::EAX;
     case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
@@ -733,7 +734,7 @@ unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
       }
     }
     switch (Reg) {
-    default: return Reg;
+    default: llvm_unreachable("Unexpected register");
     case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
       return X86::RAX;
     case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
diff --git a/lib/Target/X86/X86RegisterInfo.h b/lib/Target/X86/X86RegisterInfo.h
index 1bc32cbb78f..8e07030f5ac 100644
--- a/lib/Target/X86/X86RegisterInfo.h
+++ b/lib/Target/X86/X86RegisterInfo.h
@@ -141,8 +141,8 @@ public:
 
 // getX86SubSuperRegister - X86 utility function. It returns the sub or super
 // register of a specific X86 register.
-// e.g. getX86SubSuperRegister(X86::EAX, EVT::i16) return X86:AX
-unsigned getX86SubSuperRegister(unsigned, EVT, bool High=false);
+// e.g. getX86SubSuperRegister(X86::EAX, MVT::i16) return X86:AX
+unsigned getX86SubSuperRegister(unsigned, MVT::SimpleValueType, bool High=false);
 
 } // End llvm namespace
 
-- 
2.11.0