[ARM][AArch64] Armv8.4-A Enablement

Initial patch adding assembly support for Armv8.4-A.

Besides adding v8.4 as a supported architecture to the usual places, this also
adds target features for the different crypto algorithms. Armv8.4-A introduced
new crypto algorithms, made them optional, and allows different combinations:

- none of the v8.4 crypto functions are supported, which is independent of the
  implementation of the Armv8.0 SHA1 and SHA2 instructions.
- the v8.4 SHA512 and SHA3 support is implemented, in this case the Armv8.0
  SHA1 and SHA2 instructions must also be implemented.
- the v8.4 SM3 and SM4 support is implemented, which is independent of the
  implementation of the Armv8.0 SHA1 and SHA2 instructions.
- all of the v8.4 crypto functions are supported, in this case the Armv8.0 SHA1
  and SHA2 instructions must also be implemented.

The v8.4 crypto instructions are added to AArch64 only, and not AArch32,
and are made optional extensions to Armv8.2-A.

The user-facing Clang options will map on these new target features, their
naming will be compatible with GCC and added in follow-up patches.

The Armv8.4-A instruction sets can be downloaded here:
https://developer.arm.com/products/architecture/a-profile/exploration-tools

Differential Revision: https://reviews.llvm.org/D48625

llvm-svn: 335953

2 files changed, 42 insertions, 1 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64.td b/llvm/lib/Target/AArch64/AArch64.td
index c8cde5ecd59..a69d38144c7 100644
--- a/llvm/lib/Target/AArch64/AArch64.td
+++ b/llvm/lib/Target/AArch64/AArch64.td
@@ -26,8 +26,32 @@ def FeatureFPARMv8 : SubtargetFeature<"fp-armv8", "HasFPARMv8", "true",
 def FeatureNEON : SubtargetFeature<"neon", "HasNEON", "true",
   "Enable Advanced SIMD instructions", [FeatureFPARMv8]>;
 
+def FeatureSM4 : SubtargetFeature<
+    "sm4", "HasSM4", "true",
+    "Enable SM3 and SM4 support", [FeatureNEON]>;
+
+def FeatureSHA2 : SubtargetFeature<
+    "sha2", "HasSHA2", "true",
+    "Enable SHA1 and SHA256 support", [FeatureNEON]>;
+
+def FeatureSHA3 : SubtargetFeature<
+    "sha3", "HasSHA3", "true",
+    "Enable SHA512 and SHA3 support", [FeatureNEON, FeatureSHA2]>;
+
+def FeatureAES : SubtargetFeature<
+    "aes", "HasAES", "true",
+    "Enable AES support", [FeatureNEON]>;
+
+// Crypto has been split up and any combination is now valid (see the
+// crypto defintions above). Also, crypto is now context sensitive:
+// it has a different meaning for e.g. Armv8.4 than it has for Armv8.2.
+// Therefore, we rely on Clang, the user interacing tool, to pass on the
+// appropriate crypto options. But here in the backend, crypto has very little
+// meaning anymore. We kept the Crypto defintion here for backward
+// compatibility, and now imply features SHA2 and AES, which was the
+// "traditional" meaning of Crypto.
 def FeatureCrypto : SubtargetFeature<"crypto", "HasCrypto", "true",
-  "Enable cryptographic instructions", [FeatureNEON]>;
+  "Enable cryptographic instructions", [FeatureNEON, FeatureSHA2, FeatureAES]>;
 
 def FeatureCRC : SubtargetFeature<"crc", "HasCRC", "true",
   "Enable ARMv8 CRC-32 checksum instructions">;
@@ -185,6 +209,9 @@ def HasV8_2aOps : SubtargetFeature<"v8.2a", "HasV8_2aOps", "true",
 def HasV8_3aOps : SubtargetFeature<"v8.3a", "HasV8_3aOps", "true",
   "Support ARM v8.3a instructions", [HasV8_2aOps, FeatureRCPC]>;
 
+def HasV8_4aOps : SubtargetFeature<"v8.4a", "HasV8_4aOps", "true",
+  "Support ARM v8.4a instructions", [HasV8_3aOps, FeatureDotProd]>;
+
 //===----------------------------------------------------------------------===//
 // Register File Description
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/AArch64/AArch64Subtarget.h b/llvm/lib/Target/AArch64/AArch64Subtarget.h
index c6a1aa190f9..5af4c0dd9c1 100644
--- a/llvm/lib/Target/AArch64/AArch64Subtarget.h
+++ b/llvm/lib/Target/AArch64/AArch64Subtarget.h
@@ -66,6 +66,7 @@ protected:
   bool HasV8_1aOps = false;
   bool HasV8_2aOps = false;
   bool HasV8_3aOps = false;
+  bool HasV8_4aOps = false;
 
   bool HasFPARMv8 = false;
   bool HasNEON = false;
@@ -78,6 +79,14 @@ protected:
   bool HasPerfMon = false;
   bool HasFullFP16 = false;
   bool HasSPE = false;
+
+  // ARMv8.4 Crypto extensions
+  bool HasSM4 = true;
+  bool HasSHA3 = true;
+
+  bool HasSHA2 = true;
+  bool HasAES = true;
+
   bool HasLSLFast = false;
   bool HasSVE = false;
   bool HasRCPC = false;
@@ -201,6 +210,7 @@ public:
   bool hasV8_1aOps() const { return HasV8_1aOps; }
   bool hasV8_2aOps() const { return HasV8_2aOps; }
   bool hasV8_3aOps() const { return HasV8_3aOps; }
+  bool hasV8_4aOps() const { return HasV8_4aOps; }
 
   bool hasZeroCycleRegMove() const { return HasZeroCycleRegMove; }
 
@@ -228,6 +238,10 @@ public:
   bool hasLSE() const { return HasLSE; }
   bool hasRAS() const { return HasRAS; }
   bool hasRDM() const { return HasRDM; }
+  bool hasSM4() const { return HasSM4; }
+  bool hasSHA3() const { return HasSHA3; }
+  bool hasSHA2() const { return HasSHA2; }
+  bool hasAES() const { return HasAES; }
   bool balanceFPOps() const { return BalanceFPOps; }
   bool predictableSelectIsExpensive() const {
     return PredictableSelectIsExpensive;