[ARM] Add support for Cortex-M7, FPv5-SP and FPv5-DP (LLVM)

The Cortex-M7 has 3 options for its FPU: none, FPv5-SP-D16 and
FPv5-DP-D16. FPv5 has the same instructions as FP-ARMv8, so it can be
modelled using the same target feature, and all double-precision
operations are already disabled by the fp-only-sp target features.

llvm-svn: 218747

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 7b5d8b01dfe..ab48e148cf9 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -848,6 +848,14 @@ void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
                      /* OverwriteExisting= */ false);
     break;
 
+  // FPV5_D16 is identical to FP_ARMV8 except for the number of D registers, so
+  // uses the FP_ARMV8_D16 build attribute.
+  case ARM::FPV5_D16:
+    setAttributeItem(ARMBuildAttrs::FP_arch,
+                     ARMBuildAttrs::AllowFPARMv8B,
+                     /* OverwriteExisting= */ false);
+    break;
+
   case ARM::NEON:
     setAttributeItem(ARMBuildAttrs::FP_arch,
                      ARMBuildAttrs::AllowFPv3A,