[lld-macho] Add support for -mcpu, -mattr, -code-model in LTO

[int3]

Summary

-mcpu and -code-model tests were copied from similar ones in
LLD-ELF.

There doesn't seem to be an equivalent test for -mattr in LLD-ELF, so
I've verified our behavior by cribbing a test from
CodeGen/X86/recip-fastmath.ll.

[compnerd]

I wonder if there is a good way to enumerate the desired set of options (e.g. -O is currently missing), but I don't think that there have been too many attempts to flesh out the argument handling, so we can hold off on that until we find that we have had to do this a few times.

[MaskRay]

Maybe time to add lto/ or use the lto- prefix?

[int3]

Maybe time to add lto/ or use the lto- prefix?

I think the .ll extension is pretty much only used for LTO test cases, so it seems a bit redundant to add another prefix...

I wonder if there is a good way to enumerate the desired set of options

I don't understand what you mean by "enumerate" here... could you elaborate?

[int3]

merge other LTO diffs

[thakis]

Looks like this breaks tests on mac and windows: http://45.33.8.238/mac/25017/step_10.txt

[thakis]

Win log: http://45.33.8.238/win/29622/step_10.txt

[int3]

Looking

lld/MachO/LTO.cpp

 using namespace lld;
 using namespace lld::macho;
 using namespace llvm;
 using namespace llvm::sys;
 
 static lto::Config createConfig() {
   lto::Config c;
   c.Options = initTargetOptionsFromCodeGenFlags();
+  c.CodeModel = getCodeModelFromCMModel();
   c.CPU = getCPUStr();
   c.MAttrs = getMAttrs();
   return c;
 }
 
 BitcodeCompiler::BitcodeCompiler() {
   auto backend =
       lto::createInProcessThinBackend(llvm::heavyweight_hardware_concurrency());

lld/test/MachO/codemodel.ll

+; REQUIRES: x86
+; RUN: llvm-as %s -o %t.o
+; RUN: %lld -lSystem %t.o -o %ts -mllvm -code-model=small
+; RUN: %lld -lSystem %t.o -o %tl -mllvm -code-model=large
+; RUN: llvm-objdump -d %ts | FileCheck %s --check-prefix=CHECK-SMALL
+; RUN: llvm-objdump -d %tl | FileCheck %s --check-prefix=CHECK-LARGE
+
+target triple = "x86_64-apple-darwin"
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+
+@data = internal constant [0 x i32] []
+
+define i32* @main() nounwind readonly {
+entry:
+; CHECK-SMALL-LABEL: <_main>:
+; CHECK-SMALL:       leaq    [[#]](%rip), %rax
+; CHECK-LARGE-LABEL: <_main>:
+; CHECK-LARGE:       movabsq $[[#]], %rax
+    ret i32* getelementptr ([0 x i32], [0 x i32]* @data, i64 0, i64 0)
+}