x86_64 ABI: Handle long double in union when upper eightbyte results
in a lone X87 class.
- PR3735.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66277 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 28152f2..1ae4a87 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -473,8 +473,10 @@
// MEMORY is used as class.
//
// (f) Otherwise class SSE is used.
- assert((Accum == NoClass || Accum == Integer ||
- Accum == SSE || Accum == SSEUp) &&
+
+ // Accum should never be memory (we should have returned) or
+ // ComplexX87 (because this cannot be passed in a structure).
+ assert((Accum != Memory && Accum != ComplexX87) &&
"Invalid accumulated classification during merge.");
if (Accum == Field || Field == NoClass)
return Accum;
@@ -807,11 +809,13 @@
// AMD64-ABI 3.2.3p4: Rule 7. If the class is X87UP, the value is
// returned together with the previous X87 value in %st0.
- //
- // X87UP should always be preceeded by X87, so we don't need to do
- // anything here.
case X87Up:
- assert(Lo == X87 && "Unexpected X87Up classification.");
+ // If X87Up is preceeded by X87, we don't need to do
+ // anything. However, in some cases with unions it may not be
+ // preceeded by X87. In such situations we follow gcc and pass the
+ // extra bits in an SSE reg.
+ if (Lo != X87)
+ ResType = llvm::StructType::get(ResType, llvm::Type::DoubleTy, NULL);
break;
}
@@ -874,16 +878,20 @@
// which is passed in memory.
case Memory:
case X87:
- case X87Up:
case ComplexX87:
assert(0 && "Invalid classification for hi word.");
+ break;
case NoClass: break;
case Integer:
ResType = llvm::StructType::get(ResType, llvm::Type::Int64Ty, NULL);
++neededInt;
break;
- case SSE:
+
+ // X87Up generally doesn't occur here (long double is passed in
+ // memory), except in situations involving unions.
+ case X87Up:
+ case SSE:
ResType = llvm::StructType::get(ResType, llvm::Type::DoubleTy, NULL);
++neededSSE;
break;