From f353ae184877a2d78aaa1f63646709de54fa0e76 Mon Sep 17 00:00:00 2001
From: Erich Keane <erich.keane@intel.com>
Date: Thu, 13 Sep 2018 16:58:24 +0000
Subject: [NFC]Refactor MultiVersion Resolver Emission to combine types

Previously, both types (plus the future target-clones) of
multiversioning had a separate ResolverOption structure and emission
function.  This patch combines the two, at the expense of a slightly
more expensive sorting function.

llvm-svn: 342152
---
 clang/lib/CodeGen/CodeGenModule.cpp | 47 ++++++++++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 11 deletions(-)

(limited to 'clang/lib/CodeGen/CodeGenModule.cpp')

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 6d42b3c..7df2ea7 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2441,9 +2441,22 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
                                                       llvm::Function *NewFn);
 
+static unsigned
+TargetMVPriority(const TargetInfo &TI,
+                 const CodeGenFunction::MultiVersionResolverOption &RO) {
+  unsigned Priority = 0;
+  for (StringRef Feat : RO.Conditions.Features)
+    Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
+
+  if (!RO.Conditions.Architecture.empty())
+    Priority = std::max(
+        Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
+  return Priority;
+}
+
 void CodeGenModule::emitMultiVersionFunctions() {
   for (GlobalDecl GD : MultiVersionFuncs) {
-    SmallVector<CodeGenFunction::TargetMultiVersionResolverOption, 10> Options;
+    SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
     const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
     getContext().forEachMultiversionedFunctionVersion(
         FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
@@ -2464,8 +2477,13 @@ void CodeGenModule::emitMultiVersionFunctions() {
             }
             assert(Func && "This should have just been created");
           }
-          Options.emplace_back(getTarget(), cast<llvm::Function>(Func),
-                               CurFD->getAttr<TargetAttr>()->parse());
+
+          const auto *TA = CurFD->getAttr<TargetAttr>();
+          llvm::SmallVector<StringRef, 8> Feats;
+          TA->getAddedFeatures(Feats);
+
+          Options.emplace_back(cast<llvm::Function>(Func),
+                               TA->getArchitecture(), Feats);
         });
 
     llvm::Function *ResolverFunc = cast<llvm::Function>(
@@ -2473,11 +2491,16 @@ void CodeGenModule::emitMultiVersionFunctions() {
     if (supportsCOMDAT())
       ResolverFunc->setComdat(
           getModule().getOrInsertComdat(ResolverFunc->getName()));
+
+    const TargetInfo &TI = getTarget();
     std::stable_sort(
         Options.begin(), Options.end(),
-        std::greater<CodeGenFunction::TargetMultiVersionResolverOption>());
+        [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
+              const CodeGenFunction::MultiVersionResolverOption &RHS) {
+          return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
+        });
     CodeGenFunction CGF(*this);
-    CGF.EmitTargetMultiVersionResolver(ResolverFunc, Options);
+    CGF.EmitMultiVersionResolver(ResolverFunc, Options);
   }
 }
 
@@ -2497,8 +2520,7 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
       GetOrCreateLLVMFunction(ResolverName, ResolverType, GlobalDecl{},
                               /*ForVTable=*/false));
 
-  SmallVector<CodeGenFunction::CPUDispatchMultiVersionResolverOption, 10>
-      Options;
+  SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
   const TargetInfo &Target = getTarget();
   for (const IdentifierInfo *II : DD->cpus()) {
     // Get the name of the target function so we can look it up/create it.
@@ -2515,15 +2537,18 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
         Features.begin(), Features.end(), [&Target](StringRef Feat) {
           return !Target.validateCpuSupports(Feat);
         }), Features.end());
-    Options.emplace_back(cast<llvm::Function>(Func),
-                         CodeGenFunction::GetX86CpuSupportsMask(Features));
+    Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
   }
 
   llvm::sort(
       Options.begin(), Options.end(),
-      std::greater<CodeGenFunction::CPUDispatchMultiVersionResolverOption>());
+      [](const CodeGenFunction::MultiVersionResolverOption &LHS,
+         const CodeGenFunction::MultiVersionResolverOption &RHS) {
+        return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) >
+               CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features);
+      });
   CodeGenFunction CGF(*this);
-  CGF.EmitCPUDispatchMultiVersionResolver(ResolverFunc, Options);
+  CGF.EmitMultiVersionResolver(ResolverFunc, Options);
 }
 
 /// If an ifunc for the specified mangled name is not in the module, create and
-- 
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