Subzero. x8664. Resurrects the Target.

src/IceInstX8664.cpp

 //===- subzero/src/IceInstX8664.cpp - X86-64 instruction implementation ---===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 71 matching lines @@
     Vars = Func->allocateArrayOf<Variable *>(NumVars);
     SizeT I = 0;
     if (Base)
       Vars[I++] = Base;
     if (Index)
       Vars[I++] = Index;
     assert(I == NumVars);
   }
 }
 
+namespace {
+static int32_t getRematerializableOffset(Variable *Var,
+                                         const Ice::TargetX8664 *Target) {
+  int32_t Disp = Var->getStackOffset();
+  SizeT RegNum = static_cast<SizeT>(Var->getRegNum());
+  if (RegNum == Target->getFrameReg()) {
+    Disp += Target->getFrameFixedAllocaOffset();
+  } else if (RegNum != Target->getStackReg()) {
+    llvm::report_fatal_error("Unexpected rematerializable register type");
+  }
+  return Disp;
+}
+} // end of anonymous namespace
+
 void MachineTraits<TargetX8664>::X86OperandMem::emit(const Cfg *Func) const {
   if (!BuildDefs::dump())
     return;
+  const auto *Target = static_cast<const Ice::TargetX8664 *>(Func->getTarget());
+  // If the base is rematerializable, we need to replace it with the correct
+  // physical register (esp or ebp), and update the Offset.

[Jim Stichnoth, 2015/12/20 19:27:37]

Should that be rsp/rbp?

[John, 2015/12/21 13:41:31]

Not necessarily. Because x32, even though we manipulate 64-bit register
(r[es]p), We only ever use the lower 32 bits. This became "Stack or Frame
pointer".

+  int32_t Disp = 0;
+  if (getBase() && getBase()->isRematerializable()) {
+    Disp += getRematerializableOffset(getBase(), 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
+  // value.
+  if (getIndex())
+    assert(!getIndex()->isRematerializable());
   Ostream &Str = Func->getContext()->getStrEmit();
   // Emit as Offset(Base,Index,1<<Shift). Offset is emitted without the leading
   // '$'. Omit the (Base,Index,1<<Shift) part if Base==nullptr.
-  if (!Offset) {
+  if (getOffset() == 0 && Disp == 0) {

[Jim Stichnoth, 2015/12/20 19:27:37]

Here and below, I think getOffset() should be compared against nullptr instead
of 0.

[John, 2015/12/21 13:41:31]

Done.

     // No offset, emit nothing.
+  } else if (getOffset() == 0 && Disp != 0) {
+    Str << Disp;
   } else if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(Offset)) {
-    if (Base == nullptr || CI->getValue())
+    if (Base == nullptr || CI->getValue() || Disp != 0)
       // Emit a non-zero offset without a leading '$'.
-      Str << CI->getValue();
+      Str << CI->getValue() + Disp;
   } else if (const auto *CR = llvm::dyn_cast<ConstantRelocatable>(Offset)) {
+    // TODO(sehr): ConstantRelocatable still needs updating for
+    // rematerializable base/index and Disp.
+    assert(Disp == 0);
     CR->emitWithoutPrefix(Func->getTarget());
   } else {
     llvm_unreachable("Invalid offset type for x86 mem operand");
   }
 
   if (Base || Index) {
     Str << "(";
     if (Base)
       Base->emit(Func);
     if (Index) {
       Str << ",";
       Index->emit(Func);
       if (Shift)
         Str << "," << (1u << Shift);
     }
     Str << ")";
   }
 }
 
 void MachineTraits<TargetX8664>::X86OperandMem::dump(const Cfg *Func,
                                                      Ostream &Str) const {
   if (!BuildDefs::dump())
     return;
   bool Dumped = false;
   Str << "[";
+  int32_t Disp = 0;
+  const auto *Target = static_cast<const Ice::TargetX8664 *>(Func->getTarget());
+  if (getBase() && getBase()->isRematerializable()) {
+    Disp += getRematerializableOffset(getBase(), Target);
+  }
   if (Base) {
     if (Func)
       Base->dump(Func);
     else
       Base->dump(Str);
     Dumped = true;
   }
   if (Index) {
     if (Base)
       Str << "+";
     if (Shift > 0)
       Str << (1u << Shift) << "*";
     if (Func)
       Index->dump(Func);
     else
       Index->dump(Str);
     Dumped = true;
   }
+  if (Disp) {
+    if (Disp > 0)
+      Str << "+";
+    Str << Disp;
+    Dumped = true;
+  }
   // Pretty-print the Offset.
   bool OffsetIsZero = false;
   bool OffsetIsNegative = false;
   if (!Offset) {
     OffsetIsZero = true;
   } else if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(Offset)) {
     OffsetIsZero = (CI->getValue() == 0);
     OffsetIsNegative = (static_cast<int32_t>(CI->getValue()) < 0);
   } else {
     assert(llvm::isa<ConstantRelocatable>(Offset));
   }
   if (Dumped) {
     if (!OffsetIsZero) {     // Suppress if Offset is known to be 0
       if (!OffsetIsNegative) // Suppress if Offset is known to be negative
         Str << "+";
       Offset->dump(Func, Str);
     }
   } else {
     // There is only the offset.
     Offset->dump(Func, Str);
   }
   Str << "]";
 }
 
 MachineTraits<TargetX8664>::Address
 MachineTraits<TargetX8664>::X86OperandMem::toAsmAddress(
     MachineTraits<TargetX8664>::Assembler *Asm,
-    const Ice::TargetLowering *Target) const {
-  // TODO(sehr): handle rematerializable base/index.
+    const Ice::TargetLowering *TargetLowering) const {
+  const auto *Target = static_cast<const Ice::TargetX8664 *>(TargetLowering);
   (void)Target;

[Jim Stichnoth, 2015/12/20 19:27:37]

remove this

[John, 2015/12/21 13:41:31]

Done.

-  if (getBase())
-    assert(!getBase()->isRematerializable());
+  int32_t Disp = 0;
+  if (getBase() && getBase()->isRematerializable()) {
+    Disp += getRematerializableOffset(getBase(), Target);
+  }
   if (getIndex())
     assert(!getIndex()->isRematerializable());
-  int32_t Disp = 0;
   AssemblerFixup *Fixup = nullptr;
   // Determine the offset (is it relocatable?)
   if (getOffset()) {
     if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(getOffset())) {
-      Disp = static_cast<int32_t>(CI->getValue());
+      Disp += static_cast<int32_t>(CI->getValue());
     } else if (const auto CR =
                    llvm::dyn_cast<ConstantRelocatable>(getOffset())) {
-      Disp = CR->getOffset() - 4;
-      Fixup = Asm->createFixup(PcRelFixup, CR);
+      Disp += CR->getOffset();
+      Fixup = Asm->createFixup(RelFixup, CR);
     } else {
       llvm_unreachable("Unexpected offset type");
     }
   }
 
   // Now convert to the various possible forms.
   if (getBase() && getIndex()) {
     return X8664::Traits::Address(getEncodedGPR(getBase()->getRegNum()),
                                   getEncodedGPR(getIndex()->getRegNum()),
                                   X8664::Traits::ScaleFactor(getShift()), Disp,
@@ skipping 50 matching lines @@
     Var->dump(Func);
   else
     Var->dump(Str);
   Str << ")";
 }
 
 } // namespace X86Internal
 } // end of namespace Ice
 
 X86INSTS_DEFINE_STATIC_DATA(TargetX8664)