[CodeGen][ARM] ARM runtime helper functions are not always soft-fp

Re-commit r309257 with less precise register checks in arm-float-helpers.c
test.

llvm-svn: 309263

1 files changed, 7 insertions, 10 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index b07326e06d9..12341431ac0 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -5620,17 +5620,14 @@ void ARMABIInfo::setCCs() {
   // AAPCS apparently requires runtime support functions to be soft-float, but
   // that's almost certainly for historic reasons (Thumb1 not supporting VFP
   // most likely). It's more convenient for AAPCS16_VFP to be hard-float.
-  switch (getABIKind()) {
-  case APCS:
-  case AAPCS16_VFP:
-    if (abiCC != getLLVMDefaultCC())
+
+  // The Run-time ABI for the ARM Architecture section 4.1.2 requires
+  // AEABI-complying FP helper functions to use the base AAPCS.
+  // These AEABI functions are expanded in the ARM llvm backend, all the builtin
+  // support functions emitted by clang such as the _Complex helpers follow the
+  // abiCC.
+  if (abiCC != getLLVMDefaultCC())
       BuiltinCC = abiCC;
-    break;
-  case AAPCS:
-  case AAPCS_VFP:
-    BuiltinCC = llvm::CallingConv::ARM_AAPCS;
-    break;
-  }
 }
 
 ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty,