[AArch64] Reduce +sve2-aes to an alias of +sve-aes+sve2 (#114293)

This patch introduces the amended feature flag for
[FEAT_SVE_AES](https://developer.arm.com/documentation/109697/2024_09/Feature-descriptions/The-Armv9-0-architecture-extension?lang=en#md457-the-armv90-architecture-extension__feat_FEAT_SVE_AES),
'**sve-aes**'. The existing flag associated with this feature,
'sve2-aes' must be retained as an alias of 'sve-aes' and 'sve2' for
backwards compatibility.

The
[ACLE](https://github.com/ARM-software/acle/blob/main/main/acle.md#aes-extension)
documents `__ARM_FEATURE_SVE2_AES`, which was previously defined to 1
when

> there is hardware support for the SVE2 AES (FEAT_SVE_AES) instructions
and if the associated ACLE intrinsics are available.

The front-end has been amended such that it is compatible with +sve2-aes
and +sve2+sve-aes.

1 files changed, 24 insertions, 9 deletions

diff --git a/llvm/unittests/TargetParser/TargetParserTest.cpp b/llvm/unittests/TargetParser/TargetParserTest.cpp
index d69b2d6..4bdb6ee 100644
--- a/llvm/unittests/TargetParser/TargetParserTest.cpp
+++ b/llvm/unittests/TargetParser/TargetParserTest.cpp
@@ -1297,7 +1297,7 @@ TEST(TargetParserTest, AArch64ExtensionFeatures) {
       AArch64::AEK_SIMD,         AArch64::AEK_FP16,
       AArch64::AEK_FP16FML,      AArch64::AEK_PROFILE,
       AArch64::AEK_RAS,          AArch64::AEK_SVE,
-      AArch64::AEK_SVE2,         AArch64::AEK_SVE2AES,
+      AArch64::AEK_SVE2,         AArch64::AEK_ALIAS_SVE2AES,
       AArch64::AEK_SVE2SM4,      AArch64::AEK_SVE2SHA3,
       AArch64::AEK_SVE2BITPERM,  AArch64::AEK_RCPC,
       AArch64::AEK_RAND,         AArch64::AEK_MTE,
@@ -1334,7 +1334,7 @@ TEST(TargetParserTest, AArch64ExtensionFeatures) {
       AArch64::AEK_FPRCVT,       AArch64::AEK_CMPBR,
       AArch64::AEK_LSUI,         AArch64::AEK_OCCMO,
       AArch64::AEK_PCDPHINT,     AArch64::AEK_POPS,
-  };
+      AArch64::AEK_SVEAES};
 
   std::vector<StringRef> Features;
 
@@ -1369,6 +1369,7 @@ TEST(TargetParserTest, AArch64ExtensionFeatures) {
   EXPECT_TRUE(llvm::is_contained(Features, "+sve-bfscale"));
   EXPECT_TRUE(llvm::is_contained(Features, "+sve-f16f32mm"));
   EXPECT_TRUE(llvm::is_contained(Features, "+sve2"));
+  EXPECT_TRUE(llvm::is_contained(Features, "+sve-aes"));
   EXPECT_TRUE(llvm::is_contained(Features, "+sve2-aes"));
   EXPECT_TRUE(llvm::is_contained(Features, "+sve2-sm4"));
   EXPECT_TRUE(llvm::is_contained(Features, "+sve2-sha3"));
@@ -1538,6 +1539,7 @@ TEST(TargetParserTest, AArch64ArchExtFeature) {
       {"sve-bfscale", "nosve-bfscale", "+sve-bfscale", "-sve-bfscale"},
       {"sve-f16f32mm", "nosve-f16f32mm", "+sve-f16f32mm", "-sve-f16f32mm"},
       {"sve2", "nosve2", "+sve2", "-sve2"},
+      {"sve-aes", "nosve-aes", "+sve-aes", "-sve-aes"},
       {"sve2-aes", "nosve2-aes", "+sve2-aes", "-sve2-aes"},
       {"sve2-sm4", "nosve2-sm4", "+sve2-sm4", "-sve2-sm4"},
       {"sve2-sha3", "nosve2-sha3", "+sve2-sha3", "-sve2-sha3"},
@@ -1840,7 +1842,11 @@ AArch64ExtensionDependenciesBaseArchTestParams
          {},
          {"sve", "sve-f16f32mm"}},
 
-        // sve2 -> {sve2p1, sve2-bitperm, sve2-sha3, sve2-sm4}
+        // aes -> {sve-aes}
+        {AArch64::ARMV8A, {"noaes", "sve-aes"}, {"aes", "sve-aes"}, {}},
+        {AArch64::ARMV8A, {"sve-aes", "noaes"}, {}, {"aes", "sve-aes"}},
+
+        // sve2 -> {sve2p1, sve2-bitperm, sve2-sha3, sve2-sm4, sve2-aes}
         {AArch64::ARMV8A, {"nosve2", "sve2p1"}, {"sve2", "sve2p1"}, {}},
         {AArch64::ARMV8A, {"sve2p1", "nosve2"}, {}, {"sve2", "sve2p1"}},
         {AArch64::ARMV8A,
@@ -1855,6 +1861,8 @@ AArch64ExtensionDependenciesBaseArchTestParams
         {AArch64::ARMV8A, {"sve2-sha3", "nosve2"}, {}, {"sve2", "sve2-sha3"}},
         {AArch64::ARMV8A, {"nosve2", "sve2-sm4"}, {"sve2", "sve2-sm4"}, {}},
         {AArch64::ARMV8A, {"sve2-sm4", "nosve2"}, {}, {"sve2", "sve2-sm4"}},
+        {AArch64::ARMV8A, {"nosve2", "sve2-aes"}, {"sve2", "sve2-aes"}, {}},
+        {AArch64::ARMV8A, {"sve2-aes", "nosve2"}, {}, {"sve2", "sve2-aes"}},
 
         // sve-b16b16 -> {sme-b16b16}
         {AArch64::ARMV9_4A,
@@ -1955,16 +1963,23 @@ AArch64ExtensionDependenciesBaseArchTestParams
         {AArch64::ARMV8A, {"norcpc", "rcpc3"}, {"rcpc", "rcpc3"}, {}},
         {AArch64::ARMV8A, {"rcpc3", "norcpc"}, {}, {"rcpc", "rcpc3"}},
 
-        // sve2-aes -> ssve-aes
+        // sve-aes -> {ssve-aes, sve2-aes}
         {AArch64::ARMV9_6A,
-         {"nosve2-aes", "ssve-aes"},
-         {"sve2-aes", "ssve-aes"},
+         {"nosve-aes", "ssve-aes"},
+         {"sve-aes", "ssve-aes"},
          {}},
         {AArch64::ARMV9_6A,
-         {"ssve-aes", "nosve2-aes"},
+         {"ssve-aes", "nosve-aes"},
          {},
-         {"ssve-aes", "sve2-aes"}},
-};
+         {"ssve-aes", "sve-aes"}},
+        {AArch64::ARMV9_6A,
+         {"nosve-aes", "sve2-aes"},
+         {"sve2-aes", "sve-aes"},
+         {}},
+        {AArch64::ARMV9_6A,
+         {"sve2-aes", "nosve-aes"},
+         {},
+         {"sve2-aes", "sve-aes"}}};
 
 INSTANTIATE_TEST_SUITE_P(
     AArch64ExtensionDependenciesBaseArch,