mstorsjo created this revision.
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On x86_64 mingw, long doubles are always passed indirectly as
arguments (see an existing case in WinX86_64ABIInfo::classify); we
need to take this into account when manually reading back arguments
with `va_arg` too.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D103452
Files:
clang/lib/CodeGen/TargetInfo.cpp
clang/test/CodeGen/mingw-long-double.c
Index: clang/test/CodeGen/mingw-long-double.c
===================================================================
--- clang/test/CodeGen/mingw-long-double.c
+++ clang/test/CodeGen/mingw-long-double.c
@@ -45,3 +45,16 @@
// GNU32: declare dso_local void @__mulxc3
// GNU64: declare dso_local void @__mulxc3
// MSC64: declare dso_local void @__muldc3
+
+void VarArgLD(int a, ...) {
+ // GNU32-LABEL: define{{.*}} void @VarArgLD
+ // GNU64-LABEL: define{{.*}} void @VarArgLD
+ // MSC64-LABEL: define{{.*}} void @VarArgLD
+ __builtin_va_list ap;
+ __builtin_va_start(ap, a);
+ long double LD = __builtin_va_arg(ap, long double);
+ // GNU32: bitcast i8* %argp.cur to x86_fp80*
+ // GNU64: bitcast i8* %argp.cur to x86_fp80**
+ // MSC64: bitcast i8* %argp.cur to double*
+ __builtin_va_end(ap);
+}
Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -4366,6 +4366,16 @@
if (isAggregateTypeForABI(Ty) || Ty->isMemberPointerType()) {
uint64_t Width = getContext().getTypeSize(Ty);
IsIndirect = Width > 64 || !llvm::isPowerOf2_64(Width);
+ } else if (IsMingw64) {
+ if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
+ if (BT->getKind() == BuiltinType::LongDouble) {
+ // Mingw64 GCC uses the old 80 bit extended precision floating point
+ // unit. It passes them indirectly through memory.
+ const llvm::fltSemantics *LDF = &getTarget().getLongDoubleFormat();
+ if (LDF == &llvm::APFloat::x87DoubleExtended())
+ IsIndirect = true;
+ }
+ }
}
return emitVoidPtrVAArg(CGF, VAListAddr, Ty, IsIndirect,
Index: clang/test/CodeGen/mingw-long-double.c
===================================================================
--- clang/test/CodeGen/mingw-long-double.c
+++ clang/test/CodeGen/mingw-long-double.c
@@ -45,3 +45,16 @@
// GNU32: declare dso_local void @__mulxc3
// GNU64: declare dso_local void @__mulxc3
// MSC64: declare dso_local void @__muldc3
+
+void VarArgLD(int a, ...) {
+ // GNU32-LABEL: define{{.*}} void @VarArgLD
+ // GNU64-LABEL: define{{.*}} void @VarArgLD
+ // MSC64-LABEL: define{{.*}} void @VarArgLD
+ __builtin_va_list ap;
+ __builtin_va_start(ap, a);
+ long double LD = __builtin_va_arg(ap, long double);
+ // GNU32: bitcast i8* %argp.cur to x86_fp80*
+ // GNU64: bitcast i8* %argp.cur to x86_fp80**
+ // MSC64: bitcast i8* %argp.cur to double*
+ __builtin_va_end(ap);
+}
Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -4366,6 +4366,16 @@
if (isAggregateTypeForABI(Ty) || Ty->isMemberPointerType()) {
uint64_t Width = getContext().getTypeSize(Ty);
IsIndirect = Width > 64 || !llvm::isPowerOf2_64(Width);
+ } else if (IsMingw64) {
+ if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
+ if (BT->getKind() == BuiltinType::LongDouble) {
+ // Mingw64 GCC uses the old 80 bit extended precision floating point
+ // unit. It passes them indirectly through memory.
+ const llvm::fltSemantics *LDF = &getTarget().getLongDoubleFormat();
+ if (LDF == &llvm::APFloat::x87DoubleExtended())
+ IsIndirect = true;
+ }
+ }
}
return emitVoidPtrVAArg(CGF, VAListAddr, Ty, IsIndirect,
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