commit 1255b165bf03786a6acb326150d0068f09d0bffb
author John Baldwin <jhb@FreeBSD.org> Mon Aug 14 21:49:38 2017 +0000
committer John Baldwin <jhb@FreeBSD.org> Mon Aug 14 21:49:38 2017 +0000
tree cecc450d9afc92ada572580075716b7bdeb1f24c
parent 1c617be0541e9c88500f9e2aae49a9d24f6920a3

[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

llvm/lib/Target/Mips/MipsSubtarget.cpp

diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index e160eac..cd462c7 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -60,7 +60,8 @@
 void MipsSubtarget::anchor() {}
 
 MipsSubtarget::MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
-                             bool little, const MipsTargetMachine &TM)
+                             bool little, const MipsTargetMachine &TM,
+                             unsigned StackAlignOverride)
     : MipsGenSubtargetInfo(TT, CPU, FS), MipsArchVersion(MipsDefault),
       IsLittle(little), IsSoftFloat(false), IsSingleFloat(false), IsFPXX(false),
       NoABICalls(false), IsFP64bit(false), UseOddSPReg(true),
@@ -70,10 +71,10 @@
       InMips16HardFloat(Mips16HardFloat), InMicroMipsMode(false), HasDSP(false),
       HasDSPR2(false), HasDSPR3(false), AllowMixed16_32(Mixed16_32 | Mips_Os16),
       Os16(Mips_Os16), HasMSA(false), UseTCCInDIV(false), HasSym32(false),
-      HasEVA(false), DisableMadd4(false), HasMT(false), TM(TM),
-      TargetTriple(TT), TSInfo(),
-      InstrInfo(
-          MipsInstrInfo::create(initializeSubtargetDependencies(CPU, FS, TM))),
+      HasEVA(false), DisableMadd4(false), HasMT(false),
+      StackAlignOverride(StackAlignOverride), TM(TM), TargetTriple(TT),
+      TSInfo(), InstrInfo(MipsInstrInfo::create(
+                    initializeSubtargetDependencies(CPU, FS, TM))),
       FrameLowering(MipsFrameLowering::create(*this)),
       TLInfo(MipsTargetLowering::create(TM, *this)) {
 
@@ -157,6 +158,15 @@
   if (InMips16Mode && !IsSoftFloat)
     InMips16HardFloat = true;
 
+  if (StackAlignOverride)
+    stackAlignment = StackAlignOverride;
+  else if (isABI_N32() || isABI_N64())
+    stackAlignment = 16;
+  else {
+    assert(isABI_O32() && "Unknown ABI for stack alignment!");
+    stackAlignment = 8;
+  }
+
   return *this;
 }