Use custom ABIInfo for le32/PNaCl argument codegen

This patch uses a new ABIInfo implementation specific to the le32
target, rather than falling back to DefaultABIInfo. Its behavior is
basically the same, but it also allows the regparm argument attribute.
It also includes basic tests for argument codegen and attributes.

llvm-svn: 163333

1 files changed, 86 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index bbffc9ea92b..909a6e858b2 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -389,6 +389,90 @@ ABIArgInfo DefaultABIInfo::classifyReturnType(QualType RetTy) const {
           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
 }
 
+//===----------------------------------------------------------------------===//
+// le32/PNaCl bitcode ABI Implementation
+//===----------------------------------------------------------------------===//
+
+class PNaClABIInfo : public ABIInfo {
+ public:
+  PNaClABIInfo(CodeGen::CodeGenTypes &CGT) : ABIInfo(CGT) {}
+
+  ABIArgInfo classifyReturnType(QualType RetTy) const;
+  ABIArgInfo classifyArgumentType(QualType RetTy, unsigned &FreeRegs) const;
+
+  virtual void computeInfo(CGFunctionInfo &FI) const;
+  virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
+                                 CodeGenFunction &CGF) const;
+};
+
+class PNaClTargetCodeGenInfo : public TargetCodeGenInfo {
+ public:
+  PNaClTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
+    : TargetCodeGenInfo(new PNaClABIInfo(CGT)) {}
+};
+
+void PNaClABIInfo::computeInfo(CGFunctionInfo &FI) const {
+    FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
+
+    unsigned FreeRegs = FI.getHasRegParm() ? FI.getRegParm() : 0;
+
+    for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
+         it != ie; ++it)
+      it->info = classifyArgumentType(it->type, FreeRegs);
+  }
+
+llvm::Value *PNaClABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
+                                       CodeGenFunction &CGF) const {
+  return 0;
+}
+
+ABIArgInfo PNaClABIInfo::classifyArgumentType(QualType Ty,
+                                              unsigned &FreeRegs) const {
+  if (isAggregateTypeForABI(Ty)) {
+    // Records with non trivial destructors/constructors should not be passed
+    // by value.
+    FreeRegs = 0;
+    if (isRecordWithNonTrivialDestructorOrCopyConstructor(Ty))
+      return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
+
+    return ABIArgInfo::getIndirect(0);
+  }
+
+  // Treat an enum type as its underlying type.
+  if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+    Ty = EnumTy->getDecl()->getIntegerType();
+
+  ABIArgInfo BaseInfo = (Ty->isPromotableIntegerType() ?
+          ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
+
+  // Regparm regs hold 32 bits.
+  unsigned SizeInRegs = (getContext().getTypeSize(Ty) + 31) / 32;
+  if (SizeInRegs == 0) return BaseInfo;
+  if (SizeInRegs > FreeRegs) {
+    FreeRegs = 0;
+    return BaseInfo;
+  }
+  FreeRegs -= SizeInRegs;
+  return BaseInfo.isDirect() ?
+      ABIArgInfo::getDirectInReg(BaseInfo.getCoerceToType()) :
+      ABIArgInfo::getExtendInReg(BaseInfo.getCoerceToType());
+}
+
+ABIArgInfo PNaClABIInfo::classifyReturnType(QualType RetTy) const {
+  if (RetTy->isVoidType())
+    return ABIArgInfo::getIgnore();
+
+  if (isAggregateTypeForABI(RetTy))
+    return ABIArgInfo::getIndirect(0);
+
+  // Treat an enum type as its underlying type.
+  if (const EnumType *EnumTy = RetTy->getAs<EnumType>())
+    RetTy = EnumTy->getDecl()->getIntegerType();
+
+  return (RetTy->isPromotableIntegerType() ?
+          ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
+}
+
 /// UseX86_MMXType - Return true if this is an MMX type that should use the
 /// special x86_mmx type.
 bool UseX86_MMXType(llvm::Type *IRType) {
@@ -3768,6 +3852,8 @@ const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
   default:
     return *(TheTargetCodeGenInfo = new DefaultTargetCodeGenInfo(Types));
 
+  case llvm::Triple::le32:
+    return *(TheTargetCodeGenInfo = new PNaClTargetCodeGenInfo(Types));
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:
     return *(TheTargetCodeGenInfo = new MIPSTargetCodeGenInfo(Types, true));