[ARM]: Extend -mfpu options for half-precision and vfpv3xd

Some of the the permissible ARM -mfpu options, which are supported in GCC,
are currently not present in llvm/clang.This patch adds the options:
'neon-fp16', 'vfpv3-fp16', 'vfpv3-d16-fp16', 'vfpv3xd' and 'vfpv3xd-fp16.
These are related to half-precision floating-point and single precision.

Reviewers: rengolin, ranjeet.singh

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10645

llvm-svn: 240930

2 files changed, 52 insertions, 2 deletions

diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index 4530e4155ae..738ddedccda 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -630,7 +630,7 @@ void ARMAsmPrinter::emitAttributes() {
     } else if (STI.hasVFP4())
       ATS.emitFPU(ARM::FK_NEON_VFPV4);
     else
-      ATS.emitFPU(ARM::FK_NEON);
+      ATS.emitFPU(STI.hasFP16() ? ARM::FK_NEON_FP16 : ARM::FK_NEON);
     // Emit Tag_Advanced_SIMD_arch for ARMv8 architecture
     if (STI.hasV8Ops())
       ATS.emitAttribute(ARMBuildAttrs::Advanced_SIMD_arch,
@@ -648,7 +648,13 @@ void ARMAsmPrinter::emitAttributes() {
                   ? (STI.isFPOnlySP() ? ARM::FK_FPV4_SP_D16 : ARM::FK_VFPV4_D16)
                   : ARM::FK_VFPV4);
     else if (STI.hasVFP3())
-      ATS.emitFPU(STI.hasD16() ? ARM::FK_VFPV3_D16 : ARM::FK_VFPV3);
+      ATS.emitFPU(STI.hasD16()
+                  // +d16
+                  ? (STI.isFPOnlySP()
+                     ? (STI.hasFP16() ? ARM::FK_VFPV3XD_FP16 : ARM::FK_VFPV3XD)
+                     : (STI.hasFP16() ? ARM::FK_VFPV3_D16_FP16 : ARM::FK_VFPV3_D16))
+                  // -d16
+                  : (STI.hasFP16() ? ARM::FK_VFPV3_FP16 : ARM::FK_VFPV3));
     else if (STI.hasVFP2())
       ATS.emitFPU(ARM::FK_VFPV2);
   }
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 61af583fd60..4d12bfb5d60 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -797,12 +797,44 @@ void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
                      /* OverwriteExisting= */ false);
     break;
 
+  case ARM::FK_VFPV3_FP16:
+    setAttributeItem(ARMBuildAttrs::FP_arch,
+                     ARMBuildAttrs::AllowFPv3A,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
+                     ARMBuildAttrs::AllowHPFP,
+                     /* OverwriteExisting= */ false);
+    break;
+
   case ARM::FK_VFPV3_D16:
     setAttributeItem(ARMBuildAttrs::FP_arch,
                      ARMBuildAttrs::AllowFPv3B,
                      /* OverwriteExisting= */ false);
     break;
 
+  case ARM::FK_VFPV3_D16_FP16:
+    setAttributeItem(ARMBuildAttrs::FP_arch,
+                     ARMBuildAttrs::AllowFPv3B,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
+                     ARMBuildAttrs::AllowHPFP,
+                     /* OverwriteExisting= */ false);
+    break;
+
+  case ARM::FK_VFPV3XD:
+    setAttributeItem(ARMBuildAttrs::FP_arch,
+                     ARMBuildAttrs::AllowFPv3B,
+                     /* OverwriteExisting= */ false);
+    break;
+  case ARM::FK_VFPV3XD_FP16:
+    setAttributeItem(ARMBuildAttrs::FP_arch,
+                     ARMBuildAttrs::AllowFPv3B,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
+                     ARMBuildAttrs::AllowHPFP,
+                     /* OverwriteExisting= */ false);
+    break;
+
   case ARM::FK_VFPV4:
     setAttributeItem(ARMBuildAttrs::FP_arch,
                      ARMBuildAttrs::AllowFPv4A,
@@ -842,6 +874,18 @@ void ARMTargetELFStreamer::emitFPUDefaultAttributes() {
                      /* OverwriteExisting= */ false);
     break;
 
+  case ARM::FK_NEON_FP16:
+    setAttributeItem(ARMBuildAttrs::FP_arch,
+                     ARMBuildAttrs::AllowFPv3A,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::Advanced_SIMD_arch,
+                     ARMBuildAttrs::AllowNeon,
+                     /* OverwriteExisting= */ false);
+    setAttributeItem(ARMBuildAttrs::FP_HP_extension,
+                     ARMBuildAttrs::AllowHPFP,
+                     /* OverwriteExisting= */ false);
+    break;
+
   case ARM::FK_NEON_VFPV4:
     setAttributeItem(ARMBuildAttrs::FP_arch,
                      ARMBuildAttrs::AllowFPv4A,