Implement inalloca codegen for x86 with the new inalloca design
Calls with inalloca are lowered by skipping all stores for arguments
passed in memory and the initial stack adjustment to allocate argument
memory.
Now the frontend is responsible for the memory layout, and the backend
doesn't have to do any work. As a result these changes are pretty
minimal.
Reviewers: echristo
Differential Revision: http://llvm-reviews.chandlerc.com/D2637
llvm-svn: 200596
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c177038..55e96a4 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5434,6 +5434,8 @@
int DemoteStackIdx = -100;
if (!CanLowerReturn) {
+ assert(!CS.hasInAllocaArgument() &&
+ "sret demotion is incompatible with inalloca");
uint64_t TySize = TLI->getDataLayout()->getTypeAllocSize(
FTy->getReturnType());
unsigned Align = TLI->getDataLayout()->getPrefTypeAlignment(
@@ -7142,8 +7144,18 @@
Flags.setInReg();
if (Args[i].isSRet)
Flags.setSRet();
- if (Args[i].isByVal) {
+ if (Args[i].isByVal)
Flags.setByVal();
+ if (Args[i].isInAlloca) {
+ Flags.setInAlloca();
+ // Set the byval flag for CCAssignFn callbacks that don't know about
+ // inalloca. This way we can know how many bytes we should've allocated
+ // and how many bytes a callee cleanup function will pop. If we port
+ // inalloca to more targets, we'll have to add custom inalloca handling
+ // in the various CC lowering callbacks.
+ Flags.setByVal();
+ }
+ if (Args[i].isByVal || Args[i].isInAlloca) {
PointerType *Ty = cast<PointerType>(Args[i].Ty);
Type *ElementTy = Ty->getElementType();
Flags.setByValSize(getDataLayout()->getTypeAllocSize(ElementTy));
@@ -7362,8 +7374,18 @@
Flags.setInReg();
if (F.getAttributes().hasAttribute(Idx, Attribute::StructRet))
Flags.setSRet();
- if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal)) {
+ if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal))
Flags.setByVal();
+ if (F.getAttributes().hasAttribute(Idx, Attribute::InAlloca)) {
+ Flags.setInAlloca();
+ // Set the byval flag for CCAssignFn callbacks that don't know about
+ // inalloca. This way we can know how many bytes we should've allocated
+ // and how many bytes a callee cleanup function will pop. If we port
+ // inalloca to more targets, we'll have to add custom inalloca handling
+ // in the various CC lowering callbacks.
+ Flags.setByVal();
+ }
+ if (Flags.isByVal() || Flags.isInAlloca()) {
PointerType *Ty = cast<PointerType>(I->getType());
Type *ElementTy = Ty->getElementType();
Flags.setByValSize(TD->getTypeAllocSize(ElementTy));