[ARM] Disabling vfp4 should disable fp16

ARMTargetParser::getFPUFeatures should disable fp16 whenever it
disables vfp4, as otherwise something like -mcpu=cortex-a7 -mfpu=none
leaves us with fp16 enabled (though the only effect that will have is
a wrong build attribute).

Differential Revision: http://reviews.llvm.org/D10397

llvm-svn: 239599

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/Support/TargetParser.cpp b/llvm/lib/Support/TargetParser.cpp
index 757483b9586..760cdc11f26 100644
--- a/llvm/lib/Support/TargetParser.cpp
+++ b/llvm/lib/Support/TargetParser.cpp
@@ -276,7 +276,8 @@ bool ARMTargetParser::getFPUFeatures(unsigned FPUKind,
 
   // FPU version subtarget features are inclusive of lower-numbered ones, so
   // enable the one corresponding to this version and disable all that are
-  // higher.
+  // higher. We also have to make sure to disable fp16 when vfp4 is disabled,
+  // as +vfp4 implies +fp16 but -vfp4 does not imply -fp16.
   switch (FPUNames[FPUKind].FPUVersion) {
   case 5:
     Features.push_back("+fp-armv8");
@@ -287,18 +288,21 @@ bool ARMTargetParser::getFPUFeatures(unsigned FPUKind,
     break;
   case 3:
     Features.push_back("+vfp3");
+    Features.push_back("-fp16");
     Features.push_back("-vfp4");
     Features.push_back("-fp-armv8");
     break;
   case 2:
     Features.push_back("+vfp2");
     Features.push_back("-vfp3");
+    Features.push_back("-fp16");
     Features.push_back("-vfp4");
     Features.push_back("-fp-armv8");
     break;
   case 0:
     Features.push_back("-vfp2");
     Features.push_back("-vfp3");
+    Features.push_back("-fp16");
     Features.push_back("-vfp4");
     Features.push_back("-fp-armv8");
     break;