[MIPS] Implement support for -mstack-alignment.

Summary:
This is modeled on the implementation for x86 which stores the command line
option in a 'StackAlignOverride' field in MipsSubtarget and then uses this
to compute a 'stackAlignment' value in
MipsSubtarget::initializeSubtargetDependencies.

The stackAlignment() method in MipsSubTarget is renamed to getStackAlignment()
and returns the computed 'stackAlignment'.

Reviewers: sdardis

Reviewed By: sdardis

Subscribers: llvm-commits, arichardson

Differential Revision: https://reviews.llvm.org/D35874

llvm-svn: 310891

1 files changed, 5 insertions, 4 deletions

diff --git a/llvm/lib/Target/Mips/MipsTargetMachine.cpp b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
index 4ed06471dd9..2f01b24c237 100644
--- a/llvm/lib/Target/Mips/MipsTargetMachine.cpp
+++ b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
@@ -114,11 +114,12 @@ MipsTargetMachine::MipsTargetMachine(const Target &T, const Triple &TT,
                         getEffectiveCodeModel(CM), OL),
       isLittle(isLittle), TLOF(llvm::make_unique<MipsTargetObjectFile>()),
       ABI(MipsABIInfo::computeTargetABI(TT, CPU, Options.MCOptions)),
-      Subtarget(nullptr), DefaultSubtarget(TT, CPU, FS, isLittle, *this),
+      Subtarget(nullptr), DefaultSubtarget(TT, CPU, FS, isLittle, *this,
+                                           Options.StackAlignmentOverride),
       NoMips16Subtarget(TT, CPU, FS.empty() ? "-mips16" : FS.str() + ",-mips16",
-                        isLittle, *this),
+                        isLittle, *this, Options.StackAlignmentOverride),
       Mips16Subtarget(TT, CPU, FS.empty() ? "+mips16" : FS.str() + ",+mips16",
-                      isLittle, *this) {
+                      isLittle, *this, Options.StackAlignmentOverride) {
   Subtarget = &DefaultSubtarget;
   initAsmInfo();
 }
@@ -191,7 +192,7 @@ MipsTargetMachine::getSubtargetImpl(const Function &F) const {
     // function that reside in TargetOptions.
     resetTargetOptions(F);
     I = llvm::make_unique<MipsSubtarget>(TargetTriple, CPU, FS, isLittle,
-                                         *this);
+                                         *this, Options.StackAlignmentOverride);
   }
   return I.get();
 }