[MachineOutliner] Add optsize markings to outlined functions.

[efriedma]

Summary

It doesn't matter much this late in the pipeline, but one place that does check for optsize is the function alignment code.

[paquette]

LGTM

llvm/trunk/lib/CodeGen/MachineOutliner.cpp

Function *F = dyn_cast<Function>(
       M.getOrInsertFunction(NameStream.str(), Type::getVoidTy(C)));
   assert(F && "Function was null!");
 
   // NOTE: If this is linkonceodr, then we can take advantage of linker deduping
   // which gives us better results when we outline from linkonceodr functions.
   F->setLinkage(GlobalValue::InternalLinkage);
   F->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
 
+  // FIXME: Set nounwind, so we don't generate eh_frame? Haven't verified it's
+  // necessary.
+
+  // Set optsize/minsize, so we don't insert padding between outlined
+  // functions.
+  F->addFnAttr(Attribute::OptimizeForSize);
+  F->addFnAttr(Attribute::MinSize);
+
   // Save F so that we can add debug info later if we need to.
   CreatedIRFunctions.push_back(F);
 
   BasicBlock *EntryBB = BasicBlock::Create(C, "entry", F);
   IRBuilder<> Builder(EntryBB);
   Builder.CreateRetVoid();
 
   MachineModuleInfo &MMI = getAnalysis<MachineModuleInfo>();

llvm/trunk/test/CodeGen/AArch64/machine-outliner.ll

 ; RUN: llc -verify-machineinstrs -enable-machine-outliner -mtriple=aarch64-apple-darwin < %s | FileCheck %s
+; RUN: llc -verify-machineinstrs -enable-machine-outliner -mtriple=aarch64-apple-darwin -mcpu=cortex-a53 -enable-misched=false < %s | FileCheck %s
 ; RUN: llc -verify-machineinstrs -enable-machine-outliner -enable-linkonceodr-outlining -mtriple=aarch64-apple-darwin < %s | FileCheck %s -check-prefix=ODR
 
 define linkonce_odr void @fish() #0 {
   ; CHECK-LABEL: _fish:
   ; CHECK-NOT: OUTLINED
   ; ODR: [[OUTLINED:OUTLINED_FUNCTION_[0-9]+]]
   ; ODR-NOT: ret
   %1 = alloca i32, align 4
define void @dog() #0 {
   store i32 0, i32* %1, align 4
   store i32 1, i32* %2, align 4
   store i32 2, i32* %3, align 4
   store i32 3, i32* %4, align 4
   ret void
 }
 
 ; ODR: [[OUTLINED]]:
-; CHECK: [[OUTLINED]]:
+; CHECK: .p2align 2
+; CHECK-NEXT: [[OUTLINED]]:
 ; CHECK-DAG: orr w8, wzr, #0x1
 ; CHECK-NEXT: stp w8, wzr, [sp, #8]
 ; CHECK-NEXT: orr w8, wzr, #0x2
 ; CHECK-NEXT: str w8, [sp, #4]
 ; CHECK-NEXT: orr w8, wzr, #0x3
 ; CHECK-NEXT: str w8, [sp], #16
 ; CHECK-NEXT: ret
 
 attributes #0 = { noredzone "target-cpu"="cyclone" }