Handle functions with struct arguments or return types and the regparm
attribute. It is a variation of the x86_64 ABI:
* A struct returned indirectly uses the first register argument to pass the
pointer.
* Floats, Doubles and structs containing only one of them are not passed in
registers.
* Other structs are split into registers if they fit on the remaining ones.
Otherwise they are passed in memory.
* When a struct doesn't fit it still consumes the registers.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161022 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 9deec19..7d2b9d3 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -983,14 +983,18 @@
case ABIArgInfo::Ignore:
break;
- case ABIArgInfo::Indirect:
- PAL.push_back(llvm::AttributeWithIndex::get(Index,
- llvm::Attribute::StructRet));
+ case ABIArgInfo::Indirect: {
+ llvm::Attributes SRETAttrs = llvm::Attribute::StructRet;
+ if (RetAI.getInReg())
+ SRETAttrs |= llvm::Attribute::InReg;
+ PAL.push_back(llvm::AttributeWithIndex::get(Index, SRETAttrs));
+
++Index;
// sret disables readnone and readonly
FuncAttrs &= ~(llvm::Attribute::ReadOnly |
llvm::Attribute::ReadNone);
break;
+ }
case ABIArgInfo::Expand:
llvm_unreachable("Invalid ABI kind for return argument");
@@ -999,14 +1003,6 @@
if (RetAttrs)
PAL.push_back(llvm::AttributeWithIndex::get(0, RetAttrs));
- // FIXME: RegParm should be reduced in case of global register variable.
- signed RegParm;
- if (FI.getHasRegParm())
- RegParm = FI.getRegParm();
- else
- RegParm = CodeGenOpts.NumRegisterParameters;
-
- unsigned PointerWidth = getContext().getTargetInfo().getPointerWidth(0);
for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(),
ie = FI.arg_end(); it != ie; ++it) {
QualType ParamType = it->type;
@@ -1024,22 +1020,22 @@
Attrs |= llvm::Attribute::ZExt;
// FALL THROUGH
case ABIArgInfo::Direct:
- if (RegParm > 0 &&
- (ParamType->isIntegerType() || ParamType->isPointerType() ||
- ParamType->isReferenceType())) {
- RegParm -=
- (Context.getTypeSize(ParamType) + PointerWidth - 1) / PointerWidth;
- if (RegParm >= 0)
+ if (AI.getInReg())
Attrs |= llvm::Attribute::InReg;
- }
+
// FIXME: handle sseregparm someday...
// Increment Index if there is padding.
Index += (AI.getPaddingType() != 0);
if (llvm::StructType *STy =
- dyn_cast<llvm::StructType>(AI.getCoerceToType()))
- Index += STy->getNumElements()-1; // 1 will be added below.
+ dyn_cast<llvm::StructType>(AI.getCoerceToType())) {
+ unsigned Extra = STy->getNumElements()-1; // 1 will be added below.
+ if (Attrs != llvm::Attribute::None)
+ for (unsigned I = 0; I < Extra; ++I)
+ PAL.push_back(llvm::AttributeWithIndex::get(Index + I, Attrs));
+ Index += Extra;
+ }
break;
case ABIArgInfo::Indirect: