Index: cfe/trunk/lib/Basic/Targets.cpp =================================================================== --- cfe/trunk/lib/Basic/Targets.cpp +++ cfe/trunk/lib/Basic/Targets.cpp @@ -2335,7 +2335,8 @@ public: X86TargetInfo(const llvm::Triple &Triple) : TargetInfo(Triple) { BigEndian = false; - LongDoubleFormat = &llvm::APFloat::x87DoubleExtended; + LongDoubleFormat = Triple.isOSIAMCU() ? &llvm::APFloat::IEEEdouble + : &llvm::APFloat::x87DoubleExtended; } unsigned getFloatEvalMethod() const override { // X87 evaluates with 80 bits "long double" precision. @@ -3370,6 +3371,11 @@ } if (CPU >= CK_i586) Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8"); + + if (getTriple().isOSIAMCU()) { + Builder.defineMacro("__iamcu"); + Builder.defineMacro("__iamcu__"); + } } bool X86TargetInfo::hasFeature(StringRef Feature) const { Index: cfe/trunk/test/CodeGen/x86_32-arguments-iamcu.c =================================================================== --- cfe/trunk/test/CodeGen/x86_32-arguments-iamcu.c +++ cfe/trunk/test/CodeGen/x86_32-arguments-iamcu.c @@ -56,3 +56,7 @@ // insane. // CHECK-LABEL: define i32 @varArgs(i32 inreg %i1, ...) int varArgs(int i1, ...) { return i1; } + +// CHECK-LABEL: define double @longDoubleArg(double %ld1) +long double longDoubleArg(long double ld1) { return ld1; } + Index: cfe/trunk/test/Preprocessor/elfiamcu-predefines.c =================================================================== --- cfe/trunk/test/Preprocessor/elfiamcu-predefines.c +++ cfe/trunk/test/Preprocessor/elfiamcu-predefines.c @@ -0,0 +1,5 @@ +// RUN: %clang_cc1 -E -dM -triple i586-intel-elfiamcu | FileCheck %s + +// CHECK: #define __iamcu +// CHECK: #define __iamcu__ +