When trying to pass an argument on the stack, assume LLVM will do the right
thing for non-aggregate types.
- Otherwise we unnecessarily pin values to the stack and currently end up
triggering a backend bug in one case.
- This loose cooperation with LLVM to implement the ABI is pretty ugly.
- <rdar://problem/6918722> [irgen] clang miscompile of many pointer varargs on
x86-64
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72419 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index ce98f8c..ea0b887 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -571,6 +571,11 @@
const llvm::Type *CoerceTo,
ASTContext &Context) const;
+ /// getIndirectResult - Give a source type \arg Ty, return a suitable result
+ /// such that the argument will be passed in memory.
+ ABIArgInfo getIndirectResult(QualType Ty,
+ ASTContext &Context) const;
+
ABIArgInfo classifyReturnType(QualType RetTy,
ASTContext &Context) const;
@@ -871,6 +876,17 @@
return ABIArgInfo::getCoerce(CoerceTo);
}
+ABIArgInfo X86_64ABIInfo::getIndirectResult(QualType Ty,
+ ASTContext &Context) const {
+ // If this is a scalar LLVM value then assume LLVM will pass it in the right
+ // place naturally.
+ if (!CodeGenFunction::hasAggregateLLVMType(Ty))
+ return ABIArgInfo::getDirect();
+
+ // FIXME: Set alignment correctly.
+ return ABIArgInfo::getIndirect(0);
+}
+
ABIArgInfo X86_64ABIInfo::classifyReturnType(QualType RetTy,
ASTContext &Context) const {
// AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the
@@ -895,7 +911,7 @@
// AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via
// hidden argument.
case Memory:
- return ABIArgInfo::getIndirect(0);
+ return getIndirectResult(RetTy, Context);
// AMD64-ABI 3.2.3p4: Rule 3. If the class is INTEGER, the next
// available register of the sequence %rax, %rdx is used.
@@ -991,7 +1007,7 @@
// COMPLEX_X87, it is passed in memory.
case X87:
case ComplexX87:
- return ABIArgInfo::getIndirect(0);
+ return getIndirectResult(Ty, Context);
case SSEUp:
case X87Up:
@@ -1076,7 +1092,7 @@
freeIntRegs -= neededInt;
freeSSERegs -= neededSSE;
} else {
- it->info = ABIArgInfo::getIndirect(0);
+ it->info = getIndirectResult(it->type, Context);
}
}
}