Merge fixed alloca stack adjustments into the prolog

src/IceInstX8632.cpp

Index: src/IceInstX8632.cpp
diff --git a/src/IceInstX8632.cpp b/src/IceInstX8632.cpp
index 2c2f09ca83cbee31035af787e4b76a619446bd8a..83839600407f7491cb76374f519789489e112f34 100644
--- a/src/IceInstX8632.cpp
+++ b/src/IceInstX8632.cpp
@@ -98,17 +98,33 @@ MachineTraits<TargetX8632>::X86OperandMem::X86OperandMem(
   }
 }
 
+namespace {
+static int32_t GetRematerializableOffset(Variable *Var, bool IgnoreStackAdjust,
+                                         const Ice::TargetLowering *Target) {

[John, 2015/11/16 14:00:02]

const Ice::TargetX8632 *? I would hope llvm would devirtualize the call to
getStackReg and getFrameReg if you passed a concrete, final class.

[sehr, 2015/11/16 18:42:24]

Done.

+  int32_t Disp = 0;
+  Disp += Var->getStackOffset();
+  if (static_cast<SizeT>(Var->getRegNum()) == Target->getStackReg()) {

[Jim Stichnoth, 2015/11/16 14:47:57]

Pull "static_cast<SizeT>(Var->getRegNum())" out of the if/then/else construct
for clarity?

SizeT RegNum = static_cast<SizeT>(Var->getRegNum());
if (RegNum == Target->getStackReg()) {

[sehr, 2015/11/16 18:42:24]

Done.

+    if (!IgnoreStackAdjust)
+      Disp += Target->getStackAdjustment();
+  } else if (static_cast<SizeT>(Var->getRegNum()) == Target->getFrameReg()) {
+    Disp += Target->getFrameFixedAllocaOffset();
+  } else {
+    llvm_unreachable("Unexpected rematerializable register type");

[Jim Stichnoth, 2015/11/16 14:47:57]

llvm::report_fatal_error

[sehr, 2015/11/16 18:42:24]

Done.

+  }
+  return Disp;
+}
+}  // end namespace

[Jim Stichnoth, 2015/11/16 14:47:57]

end of anonymous namespace

[sehr, 2015/11/16 18:42:24]

Done.

+
 void MachineTraits<TargetX8632>::X86OperandMem::emit(const Cfg *Func) const {
   if (!BuildDefs::dump())
     return;
-  const ::Ice::TargetLowering *Target = Func->getTarget();
+  Ice::TargetLowering *Target = Func->getTarget();

[Jim Stichnoth, 2015/11/16 14:47:57]

Retain the const?

[sehr, 2015/11/16 18:42:24]

Done.

   // If the base is rematerializable, we need to replace it with the correct
   // physical register (esp or ebp), and update the Offset.
   int32_t Disp = 0;
   if (getBase() && getBase()->isRematerializable()) {
-    Disp += getBase()->getStackOffset();
-    if (!getIgnoreStackAdjust())
-      Disp += Target->getStackAdjustment();
+    Disp += GetRematerializableOffset(getBase(), getIgnoreStackAdjust(),
+                                      Target);
   }
   // The index should never be rematerializable.  But if we ever allow it, then
   // we should make sure the rematerialization offset is shifted by the Shift
@@ -135,7 +151,7 @@ void MachineTraits<TargetX8632>::X86OperandMem::emit(const Cfg *Func) const {
     // TODO(sehr): ConstantRelocatable still needs updating for
     // rematerializable base/index and Disp.
     assert(Disp == 0);
-    CR->emitWithoutPrefix(Func->getTarget());
+    CR->emitWithoutPrefix(Target);
   } else {
     llvm_unreachable("Invalid offset type for x86 mem operand");
   }
@@ -166,9 +182,8 @@ void MachineTraits<TargetX8632>::X86OperandMem::dump(const Cfg *Func,
   Str << "[";
   int32_t Disp = 0;
   if (getBase() && getBase()->isRematerializable()) {
-    Disp += getBase()->getStackOffset();
-    if (!getIgnoreStackAdjust())
-      Disp += Func->getTarget()->getStackAdjustment();
+    Disp += GetRematerializableOffset(getBase(), getIgnoreStackAdjust(),
+                                      Func->getTarget());
   }
   if (getBase()) {
     if (Func)
@@ -233,10 +248,8 @@ MachineTraits<TargetX8632>::X86OperandMem::toAsmAddress(
     const Ice::TargetLowering *Target) const {
   int32_t Disp = 0;
   if (getBase() && getBase()->isRematerializable()) {
-    Disp += getBase()->getStackOffset();
-    if (!getIgnoreStackAdjust()) {
-      Disp += Target->getStackAdjustment();
-    }
+    Disp += GetRematerializableOffset(getBase(), getIgnoreStackAdjust(),
+                                      Target);
   }
   // The index should never be rematerializable.  But if we ever allow it, then
   // we should make sure the rematerialization offset is shifted by the Shift