ARM: correct handling of .fpu directive

The FPU directive permits the user to switch the target FPU, enabling
instructions that would be otherwise unavailable.  However, when configuring the
new subtarget features, we would not enable the implied functions for newer
FPUs.  This would result in invalid rejection of valid input.  Ensure that we
inherit the implied FPU functionality when enabling newer versions of the FPU.
Fortunately, these are mostly hierarchical, unlike the CPUs.

Addresses PR22395.

llvm-svn: 227584

1 files changed, 35 insertions, 23 deletions

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 6a00b28f37a..96f3b4e6432 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -9191,27 +9191,39 @@ bool ARMAsmParser::parseDirectiveCPU(SMLoc L) {
 // FIXME: This is duplicated in getARMFPUFeatures() in
 // tools/clang/lib/Driver/Tools.cpp
 static const struct {
-  const unsigned Fpu;
+  const unsigned ID;
   const uint64_t Enabled;
   const uint64_t Disabled;
-} Fpus[] = {
-      {ARM::VFP, ARM::FeatureVFP2, ARM::FeatureNEON},
-      {ARM::VFPV2, ARM::FeatureVFP2, ARM::FeatureNEON},
-      {ARM::VFPV3, ARM::FeatureVFP3, ARM::FeatureNEON},
-      {ARM::VFPV3_D16, ARM::FeatureVFP3 | ARM::FeatureD16, ARM::FeatureNEON},
-      {ARM::VFPV4, ARM::FeatureVFP4, ARM::FeatureNEON},
-      {ARM::VFPV4_D16, ARM::FeatureVFP4 | ARM::FeatureD16, ARM::FeatureNEON},
-      {ARM::FPV5_D16, ARM::FeatureFPARMv8 | ARM::FeatureD16,
-       ARM::FeatureNEON | ARM::FeatureCrypto},
-      {ARM::FP_ARMV8, ARM::FeatureFPARMv8,
-       ARM::FeatureNEON | ARM::FeatureCrypto},
-      {ARM::NEON, ARM::FeatureNEON, 0},
-      {ARM::NEON_VFPV4, ARM::FeatureVFP4 | ARM::FeatureNEON, 0},
-      {ARM::NEON_FP_ARMV8, ARM::FeatureFPARMv8 | ARM::FeatureNEON,
-       ARM::FeatureCrypto},
-      {ARM::CRYPTO_NEON_FP_ARMV8,
-       ARM::FeatureFPARMv8 | ARM::FeatureNEON | ARM::FeatureCrypto, 0},
-      {ARM::SOFTVFP, 0, 0},
+} FPUs[] = {
+    {ARM::VFP, ARM::FeatureVFP2, ARM::FeatureNEON},
+    {ARM::VFPV2, ARM::FeatureVFP2, ARM::FeatureNEON},
+    {ARM::VFPV3, ARM::FeatureVFP2 | ARM::FeatureVFP3, ARM::FeatureNEON},
+    {ARM::VFPV3_D16, ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureD16,
+     ARM::FeatureNEON},
+    {ARM::VFPV4, ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureVFP4,
+     ARM::FeatureNEON},
+    {ARM::VFPV4_D16,
+     ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureVFP4 | ARM::FeatureD16,
+     ARM::FeatureNEON},
+    {ARM::FPV5_D16, ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureVFP4 |
+                        ARM::FeatureFPARMv8 | ARM::FeatureD16,
+     ARM::FeatureNEON | ARM::FeatureCrypto},
+    {ARM::FP_ARMV8, ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureVFP4 |
+                        ARM::FeatureFPARMv8,
+     ARM::FeatureNEON | ARM::FeatureCrypto},
+    {ARM::NEON, ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureNEON, 0},
+    {ARM::NEON_VFPV4,
+     ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureVFP4 | ARM::FeatureNEON,
+     0},
+    {ARM::NEON_FP_ARMV8,
+     ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureVFP4 |
+         ARM::FeatureFPARMv8 | ARM::FeatureNEON,
+     ARM::FeatureCrypto},
+    {ARM::CRYPTO_NEON_FP_ARMV8,
+     ARM::FeatureVFP2 | ARM::FeatureVFP3 | ARM::FeatureVFP4 |
+         ARM::FeatureFPARMv8 | ARM::FeatureNEON | ARM::FeatureCrypto,
+     0},
+    {ARM::SOFTVFP, 0, 0},
 };
 
 /// parseDirectiveFPU
@@ -9229,14 +9241,14 @@ bool ARMAsmParser::parseDirectiveFPU(SMLoc L) {
     return false;
   }
 
-  for (const auto &Fpu : Fpus) {
-    if (Fpu.Fpu != ID)
+  for (const auto &Entry : FPUs) {
+    if (Entry.ID != ID)
       continue;
 
     // Need to toggle features that should be on but are off and that
     // should off but are on.
-    uint64_t Toggle = (Fpu.Enabled & ~STI.getFeatureBits()) |
-                      (Fpu.Disabled & STI.getFeatureBits());
+    uint64_t Toggle = (Entry.Enabled & ~STI.getFeatureBits()) |
+                      (Entry.Disabled & STI.getFeatureBits());
     setAvailableFeatures(ComputeAvailableFeatures(STI.ToggleFeature(Toggle)));
     break;
   }