Fix LLVM's handling and detection of skylake and cannonlake CPUs

Summary:
 - Rename `"skylake"` == SkylakeServerProc to `"skylake-avx512"`
 - Change `"skylake"` to denote SkylakeClientProc
 - Fix the detection of cpu family 6 and model 94 to be
   SkylakeClientProc instead of SkylakeServerProc
 - Remove the `"cnl"` for CannonLake

Reviewers: craig.topper, delena

Subscribers: zansari, echristo, qcolombet, RKSimon, spatel, DavidKreitzer, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D17090

llvm-svn: 261482
diff --git a/llvm/lib/Support/Host.cpp b/llvm/lib/Support/Host.cpp
index ffad1d7..1ca8eac 100644
--- a/llvm/lib/Support/Host.cpp
+++ b/llvm/lib/Support/Host.cpp
@@ -373,6 +373,7 @@
 
       // Skylake:
       case 78:
+        return "skylake-avx512";
       case 94:
         return "skylake";
 
diff --git a/llvm/lib/Target/X86/X86.td b/llvm/lib/Target/X86/X86.td
index 7412914..c805fe3 100644
--- a/llvm/lib/Target/X86/X86.td
+++ b/llvm/lib/Target/X86/X86.td
@@ -474,7 +474,7 @@
 // FIXME: define SKL model
 class SkylakeClientProc<string Name> : ProcModel<Name, HaswellModel,
                                                  SKLFeatures.Value, []>;
-def : SkylakeClientProc<"skl">;
+def : SkylakeClientProc<"skylake">;
 
 // FIXME: define KNL model
 class KnightsLandingProc<string Name> : ProcModel<Name, HaswellModel,
@@ -508,7 +508,7 @@
 // FIXME: define SKX model
 class SkylakeServerProc<string Name> : ProcModel<Name, HaswellModel,
                                                  SKXFeatures.Value, []>;
-def : SkylakeServerProc<"skylake">;
+def : SkylakeServerProc<"skylake-avx512">;
 def : SkylakeServerProc<"skx">; // Legacy alias.
 
 def CNLFeatures : ProcessorFeatures<SKXFeatures.Value, [
@@ -520,7 +520,6 @@
 class CannonlakeProc<string Name> : ProcModel<Name, HaswellModel,
                                               CNLFeatures.Value, []>;
 def : CannonlakeProc<"cannonlake">;
-def : CannonlakeProc<"cnl">;
 
 // AMD CPUs.