[RISCV] Update Zvk shorthand extension to 1.0.0-rc1

[Jim]

Summary

1. Zvbc is not part of Zvkn.
2. Zvbc is not part of Zvks.
3. Add extensions implied into shorthand extension.

Also arrange its definition order as more closely its order in document.

Please refer to https://reviews.llvm.org/D152117 and https://reviews.llvm.org/D153836.

Document: https://github.com/riscv/riscv-crypto/releases/download/v20230620/riscv-crypto-spec-vector.pdf

[ego]

Thanks for fixing the expansion lists. I had missed them in the late Zvknc/Zvkng/... change of semantics.

llvm/lib/Target/RISCV/RISCVFeatures.td

599–639

As we are breaking the strict alphabetic ordering between Zvk sub-extensions, please add a marker to indicate the logic in the ordering.

For example:
// Zvk short-hand extensions

604

A few questions to improve my understanding. I am confused about the interactions between RISCVFeatures.td and RISCVISAInfo.cpp.

Prior to this commit, we did not list the implied extensions as part of the shorthand extensions. An expansion occurred during ISA string processing in llvm/lib/Support/RISCVISAInfo.cpp. Was this expansion missing in some cases, or are we now duplicating the expansion logic?

In RISCVISAInfo.cpp, there is also logic (see CombineIntoExts) to reveal the existence of those shorthand extensions when every component sub-extension has been declared. Is similar logic in place for those FeatureStdExt...?

[Jim]

llvm/lib/Target/RISCV/RISCVFeatures.td

604

I am also not sure should we add the impiled extension as part of the shorthand extension in RISCVFeatures.td.
That I saw FeatureStdExtZkn and FeatureStdExtZks has listed the impiled extensions.

[ego]

LGTM as it seems to be a strict improvement (fixes incorrectly listed sub-extensions, encodes more information).

"git blame" points to Craig as a major contributor to this file, I'll defer to him on whether listing those expansions in two locations is the right thing to do.

[craig.topper]

RISCVFeatures.td does feature implication for llc -mattr= which does not use RISCVISAInfo.cpp. It could also be used by frontends other than clang that might not use RISCVISAInfo.cpp either. Those frontends might just expose something like llc's -mattr interface instead of having target specific logic.

There is no equivalent of CombineIntoExts for RISCVFeatures.td. The only use for CombineIntoExts right now is so the frontend will set the preprocessor define for the shorthand extension.

The duplication is unfortunate. Other targets also have some similar duplication.

[craig.topper]

LGTM, other than Eric's request for a comment in the .td file.

[Jim]

Address comment.

llvm/lib/Target/RISCV/RISCVFeatures.td

 
 def FeatureStdExtZvkg
     : SubtargetFeature<"experimental-zvkg", "HasStdExtZvkg", "true",
                        "'Zvkg' (Vector GCM instructions for Cryptography)">;
 def HasStdExtZvkg : Predicate<"Subtarget->hasStdExtZvkg()">,
                               AssemblerPredicate<(all_of FeatureStdExtZvkg),
                               "'Zvkg' (Vector GCM instructions for Cryptography)">;
 
-def FeatureStdExtZvkn
-    : SubtargetFeature<"experimental-zvkn", "HasStdExtZvkn", "true",
-                       "This extension is shorthand for the following set of "
-                       "other extensions: Zvkned, Zvknhb, Zvbb, Zvbc, and Zvkt.">;
-
-def FeatureStdExtZvknc
-    : SubtargetFeature<"experimental-zvknc", "HasStdExtZvknc", "true",
-                       "This extension is shorthand for the following set of "
-                       "other extensions: Zvkn and Zvbc.">;
-
 def FeatureStdExtZvkned
     : SubtargetFeature<"experimental-zvkned", "HasStdExtZvkned", "true",
                        "'Zvkned' (Vector AES Encryption & Decryption (Single Round))">;
 def HasStdExtZvkned : Predicate<"Subtarget->hasStdExtZvkned()">,
                                 AssemblerPredicate<(all_of FeatureStdExtZvkned),
                                 "'Zvkned' (Vector AES Encryption & Decryption (Single Round))">;
 
-def FeatureStdExtZvkng
-    : SubtargetFeature<"experimental-zvkng", "HasStdExtZvkng", "true",
-                       "This extension is shorthand for the following set of "
-                       "other extensions: Zvkn and Zvkg.">;
-
 def FeatureStdExtZvknha
     : SubtargetFeature<"experimental-zvknha", "HasStdExtZvknha", "true",
                        "'Zvknha' (Vector SHA-2 (SHA-256 only))">;
 
 def FeatureStdExtZvknhb
     : SubtargetFeature<"experimental-zvknhb", "HasStdExtZvknhb", "true",
                        "'Zvknhb' (Vector SHA-2 (SHA-256 and SHA-512))",
                        [FeatureStdExtZvknha]>;
 def HasStdExtZvknha : Predicate<"Subtarget->hasStdExtZvknha()">,
                                 AssemblerPredicate<(all_of FeatureStdExtZvknha),
                                 "'Zvknha' (Vector SHA-2 (SHA-256 only))">;
 
-def FeatureStdExtZvks
-    : SubtargetFeature<"experimental-zvks", "HasStdExtZvks", "true",
-                       "This extension is shorthand for the following set of "
-                       "other extensions: Zvksed, Zvksh, Zvbb, Zvbc, and Zvkt.">;
-
-def FeatureStdExtZvksc
-    : SubtargetFeature<"experimental-zvksc", "HasStdExtZvksc", "true",
-                       "This extension is shorthand for the following set of "
-                       "other extensions: Zvks and Zvbc.">;
-
 def FeatureStdExtZvksed
     : SubtargetFeature<"experimental-zvksed", "HasStdExtZvksed", "true",
                        "'Zvksed' (SM4 Block Cipher Instructions)">;
 def HasStdExtZvksed : Predicate<"Subtarget->hasStdExtZvksed()">,
                                 AssemblerPredicate<(all_of FeatureStdExtZvksed),
                                 "'Zvksed' (SM4 Block Cipher Instructions)">;
 
-def FeatureStdExtZvksg
-    : SubtargetFeature<"experimental-zvksg", "HasStdExtZvksg", "true",
-                       "This extension is shorthand for the following set of "
-                       "other extensions: Zvks and Zvkg.">;
-
 def FeatureStdExtZvksh
     : SubtargetFeature<"experimental-zvksh", "HasStdExtZvksh", "true",
                        "'Zvksh' (SM3 Hash Function Instructions)">;
 def HasStdExtZvksh : Predicate<"Subtarget->hasStdExtZvksh()">,
                                AssemblerPredicate<(all_of FeatureStdExtZvksh),
                                "'Zvksh' (SM3 Hash Function Instructions)">;
 
 def FeatureStdExtZvkt
     : SubtargetFeature<"experimental-zvkt", "HasStdExtZvkt", "true",
                        "'Zvkt' (Vector Data-Independent Execution Latency)">;
 
+// Zvk short-hand extensions
+
+def FeatureStdExtZvkn
+    : SubtargetFeature<"experimental-zvkn", "HasStdExtZvkn", "true",
+                       "This extension is shorthand for the following set of "
+                       "other extensions: Zvkned, Zvknhb, Zvbb and Zvkt.",
+                       [FeatureStdExtZvkned, FeatureStdExtZvknhb,
+                        FeatureStdExtZvbb, FeatureStdExtZvkt]>;
+
+def FeatureStdExtZvknc
+    : SubtargetFeature<"experimental-zvknc", "HasStdExtZvknc", "true",
+                       "This extension is shorthand for the following set of "
+                       "other extensions: Zvkn and Zvbc.",
+                       [FeatureStdExtZvkn, FeatureStdExtZvbc]>;
+
+def FeatureStdExtZvkng
+    : SubtargetFeature<"experimental-zvkng", "HasStdExtZvkng", "true",
+                       "This extension is shorthand for the following set of "
+                       "other extensions: Zvkn and Zvkg.",
+                       [FeatureStdExtZvkn, FeatureStdExtZvkg]>;
+
+def FeatureStdExtZvks
+    : SubtargetFeature<"experimental-zvks", "HasStdExtZvks", "true",
+                       "This extension is shorthand for the following set of "
+                       "other extensions: Zvksed, Zvksh, Zvbb and Zvkt.",
+                       [FeatureStdExtZvksed, FeatureStdExtZvksh,
+                        FeatureStdExtZvbb, FeatureStdExtZvkt]>;
+
+def FeatureStdExtZvksc
+    : SubtargetFeature<"experimental-zvksc", "HasStdExtZvksc", "true",
+                       "This extension is shorthand for the following set of "
+                       "other extensions: Zvks and Zvbc.",
+                       [FeatureStdExtZvks, FeatureStdExtZvbc]>;
+
+def FeatureStdExtZvksg
+    : SubtargetFeature<"experimental-zvksg", "HasStdExtZvksg", "true",
+                       "This extension is shorthand for the following set of "
+                       "other extensions: Zvks and Zvkg.",
+                       [FeatureStdExtZvks, FeatureStdExtZvkg]>;
+
 def FeatureStdExtZicond
     : SubtargetFeature<"experimental-zicond", "HasStdExtZicond", "true",
                        "'Zicond' (Integer Conditional Operations)">;
 def HasStdExtZicond : Predicate<"Subtarget->hasStdExtZicond()">,
                                 AssemblerPredicate<(all_of FeatureStdExtZicond),
                                 "'Zicond' (Integer Conditional Operations)">;
 
 def FeatureStdExtSmaia