[clang] [llvm] [RISCV][FMV] Support target_clones (PR #85786)

Piyou Chen via llvm-commits llvm-commits at lists.llvm.org
Fri Jul 12 02:17:58 PDT 2024


https://github.com/BeMg updated https://github.com/llvm/llvm-project/pull/85786

>From 38e5bef5d20d7e81170720eb56354c0392f5c902 Mon Sep 17 00:00:00 2001
From: Piyou Chen <piyou.chen at sifive.com>
Date: Wed, 5 Jun 2024 01:17:03 -0700
Subject: [PATCH 1/4] [RISCV] Add groupid/bitmask for RISC-V extension

Base on https://github.com/riscv-non-isa/riscv-c-api-doc/pull/74.

This patch defines the groupid/bitmask in RISCVFeatures.td and generates the corresponding table in RISCVTargetParserDef.inc.

The groupid/bitmask of extensions provides an abstraction layer between the compiler and runtime functions.
---
 .../llvm/TargetParser/RISCVTargetParser.h     |   8 ++
 llvm/lib/Target/RISCV/RISCVFeatures.td        | 131 ++++++++++++------
 llvm/lib/TargetParser/RISCVTargetParser.cpp   |  32 +++++
 llvm/test/TableGen/riscv-target-def.td        |  18 ++-
 llvm/utils/TableGen/RISCVTargetDefEmitter.cpp |  37 +++++
 5 files changed, 183 insertions(+), 43 deletions(-)

diff --git a/llvm/include/llvm/TargetParser/RISCVTargetParser.h b/llvm/include/llvm/TargetParser/RISCVTargetParser.h
index 5b1494efe7bdc..e998bc4ca59ee 100644
--- a/llvm/include/llvm/TargetParser/RISCVTargetParser.h
+++ b/llvm/include/llvm/TargetParser/RISCVTargetParser.h
@@ -24,6 +24,14 @@ class Triple;
 
 namespace RISCV {
 
+namespace RISCVExtensionBitmaskTable {
+struct RISCVExtensionBitmask {
+  const char *Name;
+  unsigned GroupID;
+  unsigned BitPosition;
+};
+} // namespace RISCVExtensionBitmaskTable
+
 // We use 64 bits as the known part in the scalable vector types.
 static constexpr unsigned RVVBitsPerBlock = 64;
 
diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
index d3cb2aeab41cb..125e9e2f53953 100644
--- a/llvm/lib/Target/RISCV/RISCVFeatures.td
+++ b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -37,6 +37,15 @@ class RISCVExtension<string name, int major, int minor, string desc,
   bit Experimental = false;
 }
 
+// The groupID/bitmask of RISCVExtension is used to retrieve a specific bit value 
+// from __riscv_feature_bit based on the groupID and bitmask.
+// groupID      - groupID of extension
+// bitmaskShift - bitmask shift of extension
+class RISCVExtensionBitmask<bits<3> groupID, int bitmaskShift> {
+    int GroupID = groupID;
+    int BitPos = bitmaskShift;
+}
+
 // Version of RISCVExtension to be used for Experimental extensions. This
 // sets the Experimental flag and prepends experimental- to the -mattr name.
 class RISCVExperimentalExtension<string name, int major, int minor, string desc,
@@ -52,7 +61,8 @@ class RISCVExperimentalExtension<string name, int major, int minor, string desc,
 
 def FeatureStdExtI
     : RISCVExtension<"i", 2, 1,
-                     "'I' (Base Integer Instruction Set)">;
+                     "'I' (Base Integer Instruction Set)">,
+      RISCVExtensionBitmask<0, 8>;
 
 def FeatureStdExtE
     : RISCVExtension<"e", 2, 0,
@@ -78,7 +88,8 @@ def HasStdExtZicbop : Predicate<"Subtarget->hasStdExtZicbop()">,
 
 def FeatureStdExtZicboz
     : RISCVExtension<"zicboz", 1, 0,
-                     "'Zicboz' (Cache-Block Zero Instructions)">;
+                     "'Zicboz' (Cache-Block Zero Instructions)">,
+      RISCVExtensionBitmask<0, 37>;
 def HasStdExtZicboz : Predicate<"Subtarget->hasStdExtZicboz()">,
                       AssemblerPredicate<(all_of FeatureStdExtZicboz),
                           "'Zicboz' (Cache-Block Zero Instructions)">;
@@ -113,7 +124,8 @@ def FeatureStdExtZicntr
 
 def FeatureStdExtZicond
     : RISCVExtension<"zicond", 1, 0,
-                     "'Zicond' (Integer Conditional Operations)">;
+                     "'Zicond' (Integer Conditional Operations)">,
+      RISCVExtensionBitmask<0, 38>;
 def HasStdExtZicond : Predicate<"Subtarget->hasStdExtZicond()">,
                       AssemblerPredicate<(all_of FeatureStdExtZicond),
                           "'Zicond' (Integer Conditional Operations)">;
@@ -134,7 +146,8 @@ def HasStdExtZihintpause : Predicate<"Subtarget->hasStdExtZihintpause()">,
 
 def FeatureStdExtZihintntl
     : RISCVExtension<"zihintntl", 1, 0,
-                     "'Zihintntl' (Non-Temporal Locality Hints)">;
+                     "'Zihintntl' (Non-Temporal Locality Hints)">,
+      RISCVExtensionBitmask<0, 39>;
 def HasStdExtZihintntl : Predicate<"Subtarget->hasStdExtZihintntl()">,
                          AssemblerPredicate<(all_of FeatureStdExtZihintntl),
                              "'Zihintntl' (Non-Temporal Locality Hints)">;
@@ -181,7 +194,8 @@ def HasStdExtZmmul : Predicate<"Subtarget->hasStdExtZmmul()">,
 def FeatureStdExtM
     : RISCVExtension<"m", 2, 0,
                      "'M' (Integer Multiplication and Division)",
-                     [FeatureStdExtZmmul]>;
+                     [FeatureStdExtZmmul]>,
+      RISCVExtensionBitmask<0, 12>;
 def HasStdExtM : Predicate<"Subtarget->hasStdExtM()">,
                  AssemblerPredicate<(all_of FeatureStdExtM),
                      "'M' (Integer Multiplication and Division)">;
@@ -190,14 +204,16 @@ def HasStdExtM : Predicate<"Subtarget->hasStdExtM()">,
 
 def FeatureStdExtA
     : RISCVExtension<"a", 2, 1,
-                     "'A' (Atomic Instructions)">;
+                     "'A' (Atomic Instructions)">,
+      RISCVExtensionBitmask<0, 0>;
 def HasStdExtA : Predicate<"Subtarget->hasStdExtA()">,
                  AssemblerPredicate<(all_of FeatureStdExtA),
                                     "'A' (Atomic Instructions)">;
 
 def FeatureStdExtZtso
     : RISCVExtension<"ztso", 1, 0,
-                     "'Ztso' (Memory Model - Total Store Order)">;
+                     "'Ztso' (Memory Model - Total Store Order)">,
+      RISCVExtensionBitmask<0, 47>;
 def HasStdExtZtso : Predicate<"Subtarget->hasStdExtZtso()">,
                     AssemblerPredicate<(all_of FeatureStdExtZtso),
                         "'Ztso' (Memory Model - Total Store Order)">;
@@ -227,7 +243,8 @@ def HasStdExtZabha : Predicate<"Subtarget->hasStdExtZabha()">,
 
 def FeatureStdExtZacas
     : RISCVExtension<"zacas", 1, 0,
-                     "'Zacas' (Atomic Compare-And-Swap Instructions)">;
+                     "'Zacas' (Atomic Compare-And-Swap Instructions)">,
+      RISCVExtensionBitmask<0, 26>;
 def HasStdExtZacas : Predicate<"Subtarget->hasStdExtZacas()">,
                      AssemblerPredicate<(all_of FeatureStdExtZacas),
                          "'Zacas' (Atomic Compare-And-Swap Instructions)">;
@@ -264,7 +281,8 @@ def HasStdExtZawrs : Predicate<"Subtarget->hasStdExtZawrs()">,
 def FeatureStdExtF
     : RISCVExtension<"f", 2, 2,
                      "'F' (Single-Precision Floating-Point)",
-                     [FeatureStdExtZicsr]>;
+                     [FeatureStdExtZicsr]>,
+      RISCVExtensionBitmask<0, 5>;
 def HasStdExtF : Predicate<"Subtarget->hasStdExtF()">,
                  AssemblerPredicate<(all_of FeatureStdExtF),
                                     "'F' (Single-Precision Floating-Point)">;
@@ -272,7 +290,8 @@ def HasStdExtF : Predicate<"Subtarget->hasStdExtF()">,
 def FeatureStdExtD
     : RISCVExtension<"d", 2, 2,
                      "'D' (Double-Precision Floating-Point)",
-                     [FeatureStdExtF]>;
+                     [FeatureStdExtF]>,
+      RISCVExtensionBitmask<0, 3>;
 def HasStdExtD : Predicate<"Subtarget->hasStdExtD()">,
                  AssemblerPredicate<(all_of FeatureStdExtD),
                                     "'D' (Double-Precision Floating-Point)">;
@@ -280,7 +299,8 @@ def HasStdExtD : Predicate<"Subtarget->hasStdExtD()">,
 def FeatureStdExtZfhmin
     : RISCVExtension<"zfhmin", 1, 0,
                      "'Zfhmin' (Half-Precision Floating-Point Minimal)",
-                     [FeatureStdExtF]>;
+                     [FeatureStdExtF]>,
+      RISCVExtensionBitmask<0, 36>;
 def HasStdExtZfhmin : Predicate<"Subtarget->hasStdExtZfhmin()">,
                       AssemblerPredicate<(all_of FeatureStdExtZfhmin),
                           "'Zfh' (Half-Precision Floating-Point) or "
@@ -289,7 +309,8 @@ def HasStdExtZfhmin : Predicate<"Subtarget->hasStdExtZfhmin()">,
 def FeatureStdExtZfh
     : RISCVExtension<"zfh", 1, 0,
                      "'Zfh' (Half-Precision Floating-Point)",
-                     [FeatureStdExtZfhmin]>;
+                     [FeatureStdExtZfhmin]>,
+      RISCVExtensionBitmask<0, 35>;
 def HasStdExtZfh : Predicate<"Subtarget->hasStdExtZfh()">,
                    AssemblerPredicate<(all_of FeatureStdExtZfh),
                        "'Zfh' (Half-Precision Floating-Point)">;
@@ -313,7 +334,8 @@ def HasHalfFPLoadStoreMove
 def FeatureStdExtZfa
     : RISCVExtension<"zfa", 1, 0,
                      "'Zfa' (Additional Floating-Point)",
-                     [FeatureStdExtF]>;
+                     [FeatureStdExtF]>,
+      RISCVExtensionBitmask<0, 34>;
 def HasStdExtZfa : Predicate<"Subtarget->hasStdExtZfa()">,
                    AssemblerPredicate<(all_of FeatureStdExtZfa),
                                       "'Zfa' (Additional Floating-Point)">;
@@ -356,7 +378,8 @@ def NoStdExtZhinx : Predicate<"!Subtarget->hasStdExtZhinx()">;
 
 def FeatureStdExtC
     : RISCVExtension<"c", 2, 0,
-                     "'C' (Compressed Instructions)">;
+                     "'C' (Compressed Instructions)">,
+      RISCVExtensionBitmask<0, 2>;
 def HasStdExtC : Predicate<"Subtarget->hasStdExtC()">,
                  AssemblerPredicate<(all_of FeatureStdExtC),
                                     "'C' (Compressed Instructions)">;
@@ -445,7 +468,8 @@ def HasStdExtZcmop : Predicate<"Subtarget->hasStdExtZcmop()">,
 
 def FeatureStdExtZba
     : RISCVExtension<"zba", 1, 0,
-                     "'Zba' (Address Generation Instructions)">;
+                     "'Zba' (Address Generation Instructions)">,
+      RISCVExtensionBitmask<0, 27>;
 def HasStdExtZba : Predicate<"Subtarget->hasStdExtZba()">,
                    AssemblerPredicate<(all_of FeatureStdExtZba),
                                       "'Zba' (Address Generation Instructions)">;
@@ -453,7 +477,8 @@ def NotHasStdExtZba : Predicate<"!Subtarget->hasStdExtZba()">;
 
 def FeatureStdExtZbb
     : RISCVExtension<"zbb", 1, 0,
-                     "'Zbb' (Basic Bit-Manipulation)">;
+                     "'Zbb' (Basic Bit-Manipulation)">,
+      RISCVExtensionBitmask<0, 28>;
 def HasStdExtZbb : Predicate<"Subtarget->hasStdExtZbb()">,
                    AssemblerPredicate<(all_of FeatureStdExtZbb),
                                       "'Zbb' (Basic Bit-Manipulation)">;
@@ -462,14 +487,16 @@ def NoStdExtZbb : Predicate<"!Subtarget->hasStdExtZbb()">,
 
 def FeatureStdExtZbc
     : RISCVExtension<"zbc", 1, 0,
-                     "'Zbc' (Carry-Less Multiplication)">;
+                     "'Zbc' (Carry-Less Multiplication)">,
+      RISCVExtensionBitmask<0, 29>;
 def HasStdExtZbc : Predicate<"Subtarget->hasStdExtZbc()">,
                    AssemblerPredicate<(all_of FeatureStdExtZbc),
                                       "'Zbc' (Carry-Less Multiplication)">;
 
 def FeatureStdExtZbs
     : RISCVExtension<"zbs", 1, 0,
-                     "'Zbs' (Single-Bit Instructions)">;
+                     "'Zbs' (Single-Bit Instructions)">,
+      RISCVExtensionBitmask<0, 33>;
 def HasStdExtZbs : Predicate<"Subtarget->hasStdExtZbs()">,
                    AssemblerPredicate<(all_of FeatureStdExtZbs),
                                       "'Zbs' (Single-Bit Instructions)">;
@@ -486,14 +513,16 @@ def HasStdExtB : Predicate<"Subtarget->hasStdExtB()">,
 
 def FeatureStdExtZbkb
     : RISCVExtension<"zbkb", 1, 0,
-                     "'Zbkb' (Bitmanip instructions for Cryptography)">;
+                     "'Zbkb' (Bitmanip instructions for Cryptography)">,
+      RISCVExtensionBitmask<0, 30>;
 def HasStdExtZbkb : Predicate<"Subtarget->hasStdExtZbkb()">,
                     AssemblerPredicate<(all_of FeatureStdExtZbkb),
                         "'Zbkb' (Bitmanip instructions for Cryptography)">;
 
 def FeatureStdExtZbkx
     : RISCVExtension<"zbkx", 1, 0,
-                     "'Zbkx' (Crossbar permutation instructions)">;
+                     "'Zbkx' (Crossbar permutation instructions)">,
+      RISCVExtensionBitmask<0, 32>;
 def HasStdExtZbkx : Predicate<"Subtarget->hasStdExtZbkx()">,
                     AssemblerPredicate<(all_of FeatureStdExtZbkx),
                         "'Zbkx' (Crossbar permutation instructions)">;
@@ -510,7 +539,8 @@ def HasStdExtZbbOrZbkb
 def FeatureStdExtZbkc
     : RISCVExtension<"zbkc", 1, 0,
                      "'Zbkc' (Carry-less multiply instructions for "
-                     "Cryptography)">;
+                     "Cryptography)">,
+      RISCVExtensionBitmask<0, 31>;
 def HasStdExtZbkc
     : Predicate<"Subtarget->hasStdExtZbkc()">,
       AssemblerPredicate<(all_of FeatureStdExtZbkc),
@@ -527,14 +557,16 @@ def HasStdExtZbcOrZbkc
 
 def FeatureStdExtZknd
     : RISCVExtension<"zknd", 1, 0,
-                     "'Zknd' (NIST Suite: AES Decryption)">;
+                     "'Zknd' (NIST Suite: AES Decryption)">,
+      RISCVExtensionBitmask<0, 41>;
 def HasStdExtZknd : Predicate<"Subtarget->hasStdExtZknd()">,
                     AssemblerPredicate<(all_of FeatureStdExtZknd),
                                        "'Zknd' (NIST Suite: AES Decryption)">;
 
 def FeatureStdExtZkne
     : RISCVExtension<"zkne", 1, 0,
-                     "'Zkne' (NIST Suite: AES Encryption)">;
+                     "'Zkne' (NIST Suite: AES Encryption)">,
+      RISCVExtensionBitmask<0, 42>;
 def HasStdExtZkne : Predicate<"Subtarget->hasStdExtZkne()">,
                     AssemblerPredicate<(all_of FeatureStdExtZkne),
                                        "'Zkne' (NIST Suite: AES Encryption)">;
@@ -549,21 +581,24 @@ def HasStdExtZkndOrZkne
 
 def FeatureStdExtZknh
     : RISCVExtension<"zknh", 1, 0,
-                     "'Zknh' (NIST Suite: Hash Function Instructions)">;
+                     "'Zknh' (NIST Suite: Hash Function Instructions)">,
+      RISCVExtensionBitmask<0, 43>;
 def HasStdExtZknh : Predicate<"Subtarget->hasStdExtZknh()">,
                     AssemblerPredicate<(all_of FeatureStdExtZknh),
                         "'Zknh' (NIST Suite: Hash Function Instructions)">;
 
 def FeatureStdExtZksed
     : RISCVExtension<"zksed", 1, 0,
-                     "'Zksed' (ShangMi Suite: SM4 Block Cipher Instructions)">;
+                     "'Zksed' (ShangMi Suite: SM4 Block Cipher Instructions)">,
+      RISCVExtensionBitmask<0, 44>;
 def HasStdExtZksed : Predicate<"Subtarget->hasStdExtZksed()">,
                      AssemblerPredicate<(all_of FeatureStdExtZksed),
                          "'Zksed' (ShangMi Suite: SM4 Block Cipher Instructions)">;
 
 def FeatureStdExtZksh
     : RISCVExtension<"zksh", 1, 0,
-                     "'Zksh' (ShangMi Suite: SM3 Hash Function Instructions)">;
+                     "'Zksh' (ShangMi Suite: SM3 Hash Function Instructions)">,
+      RISCVExtensionBitmask<0, 45>;
 def HasStdExtZksh : Predicate<"Subtarget->hasStdExtZksh()">,
                     AssemblerPredicate<(all_of FeatureStdExtZksh),
                         "'Zksh' (ShangMi Suite: SM3 Hash Function Instructions)">;
@@ -596,7 +631,8 @@ def FeatureStdExtZks
 
 def FeatureStdExtZkt
     : RISCVExtension<"zkt", 1, 0,
-                     "'Zkt' (Data Independent Execution Latency)">;
+                     "'Zkt' (Data Independent Execution Latency)">,
+      RISCVExtensionBitmask<0, 46>;
 
 def FeatureStdExtZk
     : RISCVExtension<"zk", 1, 0,
@@ -626,6 +662,7 @@ def FeatureStdExtZve32x
                      "with maximal 32 EEW)",
                      [FeatureStdExtZicsr, FeatureStdExtZvl32b]>;
 
+
 def FeatureStdExtZve32f
     : RISCVExtension<"zve32f", 1, 0,
                      "'Zve32f' (Vector Extensions for Embedded Processors "
@@ -653,7 +690,8 @@ def FeatureStdExtZve64d
 def FeatureStdExtV
     : RISCVExtension<"v", 1, 0,
                      "'V' (Vector Extension for Application Processors)",
-                     [FeatureStdExtZvl128b, FeatureStdExtZve64d]>;
+                     [FeatureStdExtZvl128b, FeatureStdExtZve64d]>,
+      RISCVExtensionBitmask<0, 21>;
 
 def FeatureStdExtZvfbfmin
     : RISCVExtension<"zvfbfmin", 1, 0, "'Zvbfmin' (Vector BF16 Converts)",
@@ -673,12 +711,14 @@ def HasStdExtZvfbfwma : Predicate<"Subtarget->hasStdExtZvfbfwma()">,
 def FeatureStdExtZvfhmin
     : RISCVExtension<"zvfhmin", 1, 0,
                      "'Zvfhmin' (Vector Half-Precision Floating-Point Minimal)",
-                     [FeatureStdExtZve32f]>;
+                     [FeatureStdExtZve32f]>,
+      RISCVExtensionBitmask<0, 51>;
 
 def FeatureStdExtZvfh
     : RISCVExtension<"zvfh", 1, 0,
                      "'Zvfh' (Vector Half-Precision Floating-Point)",
-                     [FeatureStdExtZvfhmin, FeatureStdExtZfhmin]>;
+                     [FeatureStdExtZvfhmin, FeatureStdExtZfhmin]>,
+      RISCVExtensionBitmask<0, 50>;
 
 def HasStdExtZfhOrZvfh
     : Predicate<"Subtarget->hasStdExtZfh() || Subtarget->hasStdExtZvfh()">,
@@ -690,7 +730,8 @@ def HasStdExtZfhOrZvfh
 
 def FeatureStdExtZvkb
     : RISCVExtension<"zvkb", 1, 0,
-                     "'Zvkb' (Vector Bit-manipulation used in Cryptography)">;
+                     "'Zvkb' (Vector Bit-manipulation used in Cryptography)">,
+      RISCVExtensionBitmask<0, 52>;
 def HasStdExtZvkb : Predicate<"Subtarget->hasStdExtZvkb()">,
                     AssemblerPredicate<(all_of FeatureStdExtZvkb),
                         "'Zvkb' (Vector Bit-manipulation used in Cryptography)">;
@@ -698,35 +739,40 @@ def HasStdExtZvkb : Predicate<"Subtarget->hasStdExtZvkb()">,
 def FeatureStdExtZvbb
     : RISCVExtension<"zvbb", 1, 0,
                      "'Zvbb' (Vector basic bit-manipulation instructions)",
-                     [FeatureStdExtZvkb]>;
+                     [FeatureStdExtZvkb]>,
+      RISCVExtensionBitmask<0, 48>;
 def HasStdExtZvbb : Predicate<"Subtarget->hasStdExtZvbb()">,
                     AssemblerPredicate<(all_of FeatureStdExtZvbb),
                         "'Zvbb' (Vector basic bit-manipulation instructions)">;
 
 def FeatureStdExtZvbc
     : RISCVExtension<"zvbc", 1, 0,
-                     "'Zvbc' (Vector Carryless Multiplication)">;
+                     "'Zvbc' (Vector Carryless Multiplication)">,
+      RISCVExtensionBitmask<0, 49>;
 def HasStdExtZvbc : Predicate<"Subtarget->hasStdExtZvbc()">,
                     AssemblerPredicate<(all_of FeatureStdExtZvbc),
                         "'Zvbc' (Vector Carryless Multiplication)">;
 
 def FeatureStdExtZvkg
     : RISCVExtension<"zvkg", 1, 0,
-                     "'Zvkg' (Vector GCM instructions for Cryptography)">;
+                     "'Zvkg' (Vector GCM instructions for Cryptography)">,
+      RISCVExtensionBitmask<0, 53>;
 def HasStdExtZvkg : Predicate<"Subtarget->hasStdExtZvkg()">,
                     AssemblerPredicate<(all_of FeatureStdExtZvkg),
                         "'Zvkg' (Vector GCM instructions for Cryptography)">;
 
 def FeatureStdExtZvkned
     : RISCVExtension<"zvkned", 1, 0,
-                     "'Zvkned' (Vector AES Encryption & Decryption (Single Round))">;
+                     "'Zvkned' (Vector AES Encryption & Decryption (Single Round))">,
+      RISCVExtensionBitmask<0, 54>;
 def HasStdExtZvkned : Predicate<"Subtarget->hasStdExtZvkned()">,
                       AssemblerPredicate<(all_of FeatureStdExtZvkned),
                           "'Zvkned' (Vector AES Encryption & Decryption (Single Round))">;
 
 def FeatureStdExtZvknha
     : RISCVExtension<"zvknha", 1, 0,
-                     "'Zvknha' (Vector SHA-2 (SHA-256 only))">;
+                     "'Zvknha' (Vector SHA-2 (SHA-256 only))">,
+      RISCVExtensionBitmask<0, 55>;
 def HasStdExtZvknha : Predicate<"Subtarget->hasStdExtZvknha()">,
                       AssemblerPredicate<(all_of FeatureStdExtZvknha),
                           "'Zvknha' (Vector SHA-2 (SHA-256 only))">;
@@ -734,7 +780,8 @@ def HasStdExtZvknha : Predicate<"Subtarget->hasStdExtZvknha()">,
 def FeatureStdExtZvknhb
     : RISCVExtension<"zvknhb", 1, 0,
                      "'Zvknhb' (Vector SHA-2 (SHA-256 and SHA-512))",
-                     [FeatureStdExtZve64x]>;
+                     [FeatureStdExtZve64x]>,
+      RISCVExtensionBitmask<0, 56>;
 def HasStdExtZvknhb : Predicate<"Subtarget->hasStdExtZvknhb()">,
                       AssemblerPredicate<(all_of FeatureStdExtZvknhb),
                           "'Zvknhb' (Vector SHA-2 (SHA-256 and SHA-512))">;
@@ -745,21 +792,24 @@ def HasStdExtZvknhaOrZvknhb : Predicate<"Subtarget->hasStdExtZvknha() || Subtarg
 
 def FeatureStdExtZvksed
     : RISCVExtension<"zvksed", 1, 0,
-                     "'Zvksed' (SM4 Block Cipher Instructions)">;
+                     "'Zvksed' (SM4 Block Cipher Instructions)">,
+      RISCVExtensionBitmask<0, 57>;
 def HasStdExtZvksed : Predicate<"Subtarget->hasStdExtZvksed()">,
                       AssemblerPredicate<(all_of FeatureStdExtZvksed),
                           "'Zvksed' (SM4 Block Cipher Instructions)">;
 
 def FeatureStdExtZvksh
     : RISCVExtension<"zvksh", 1, 0,
-                     "'Zvksh' (SM3 Hash Function Instructions)">;
+                     "'Zvksh' (SM3 Hash Function Instructions)">,
+      RISCVExtensionBitmask<0, 58>;
 def HasStdExtZvksh : Predicate<"Subtarget->hasStdExtZvksh()">,
                      AssemblerPredicate<(all_of FeatureStdExtZvksh),
                          "'Zvksh' (SM3 Hash Function Instructions)">;
 
 def FeatureStdExtZvkt
     : RISCVExtension<"zvkt", 1, 0,
-                     "'Zvkt' (Vector Data-Independent Execution Latency)">;
+                     "'Zvkt' (Vector Data-Independent Execution Latency)">,
+      RISCVExtensionBitmask<0, 59>;
 
 // Zvk short-hand extensions
 
@@ -796,7 +846,6 @@ def FeatureStdExtZvksg
     : RISCVExtension<"zvksg", 1, 0,
                      "'Zvksg' (shorthand for 'Zvks' and 'Zvkg')",
                      [FeatureStdExtZvks, FeatureStdExtZvkg]>;
-
 // Vector instruction predicates
 
 def HasVInstructions    : Predicate<"Subtarget->hasVInstructions()">,
diff --git a/llvm/lib/TargetParser/RISCVTargetParser.cpp b/llvm/lib/TargetParser/RISCVTargetParser.cpp
index 9003f9beffa7e..adb594777be80 100644
--- a/llvm/lib/TargetParser/RISCVTargetParser.cpp
+++ b/llvm/lib/TargetParser/RISCVTargetParser.cpp
@@ -119,6 +119,38 @@ void getFeaturesForCPU(StringRef CPU,
     else
       EnabledFeatures.push_back(F.substr(1));
 }
+
+namespace RISCVExtensionBitmaskTable {
+#define GET_RISCVExtensionBitmaskTable_IMPL
+#include "llvm/TargetParser/RISCVTargetParserDef.inc"
+
+} // namespace RISCVExtensionBitmaskTable
+
+namespace {
+struct LessExtName {
+  bool operator()(const RISCVExtensionBitmaskTable::RISCVExtensionBitmask &LHS,
+                  StringRef RHS) {
+    return StringRef(LHS.Name) < RHS;
+  }
+  bool
+  operator()(StringRef LHS,
+             const RISCVExtensionBitmaskTable::RISCVExtensionBitmask &RHS) {
+    return LHS < StringRef(RHS.Name);
+  }
+};
+} // namespace
+
+static RISCVExtensionBitmaskTable::RISCVExtensionBitmask
+getExtensionBitmask(StringRef ExtName) {
+  ArrayRef<RISCVExtensionBitmaskTable::RISCVExtensionBitmask> ExtBitmasks =
+      RISCVExtensionBitmaskTable::ExtensionBitmask;
+  auto *I = llvm::lower_bound(ExtBitmasks, ExtName, LessExtName());
+
+  if (I != ExtBitmasks.end())
+    return *I;
+
+  return RISCVExtensionBitmaskTable::RISCVExtensionBitmask();
+}
 } // namespace RISCV
 
 namespace RISCVVType {
diff --git a/llvm/test/TableGen/riscv-target-def.td b/llvm/test/TableGen/riscv-target-def.td
index fb58448d7ce88..9e027d18b76fb 100644
--- a/llvm/test/TableGen/riscv-target-def.td
+++ b/llvm/test/TableGen/riscv-target-def.td
@@ -12,6 +12,11 @@ class RISCVExtension<string name, int major, int minor, string desc,
   bit Experimental = false;
 }
 
+class RISCVExtensionBitmask<bits<3> groupID, int bitmaskShift> {
+  int GroupID = groupID;
+  int BitPos = bitmaskShift;
+}
+
 class RISCVExperimentalExtension<string name, int major, int minor, string desc,
                                  list<RISCVExtension> implies = [],
                                  string fieldname = !subst("Feature", "Has", NAME),
@@ -23,7 +28,8 @@ class RISCVExperimentalExtension<string name, int major, int minor, string desc,
 
 def FeatureStdExtI
     : RISCVExtension<"i", 2, 1,
-                     "'I' (Base Integer Instruction Set)">;
+                     "'I' (Base Integer Instruction Set)">,
+      RISCVExtensionBitmask<0, 8>;
 
 def FeatureStdExtZicsr
     : RISCVExtension<"zicsr", 2, 0,
@@ -36,7 +42,8 @@ def FeatureStdExtZifencei
 def FeatureStdExtF
     : RISCVExtension<"f", 2, 2,
                      "'F' (Single-Precision Floating-Point)",
-                     [FeatureStdExtZicsr]>;
+                     [FeatureStdExtZicsr]>,
+      RISCVExtensionBitmask<0, 5>;
 
 def FeatureStdExtZidummy
     : RISCVExperimentalExtension<"zidummy", 0, 1,
@@ -171,3 +178,10 @@ def ROCKET : RISCVTuneProcessorModel<"rocket",
 // CHECK-NEXT: TUNE_PROC(ROCKET, "rocket")
 
 // CHECK: #undef TUNE_PROC
+
+// CHECK: #ifdef GET_RISCVExtensionBitmaskTable_IMPL
+// CHECK-NEXT: static const RISCVExtensionBitmask ExtensionBitmask[]={
+// CHECK-NEXT:     {"f", 0, 5ULL},
+// CHECK-NEXT:     {"i", 0, 8ULL},
+// CHECK-NEXT: };
+// CHECK-NEXT: #endif
diff --git a/llvm/utils/TableGen/RISCVTargetDefEmitter.cpp b/llvm/utils/TableGen/RISCVTargetDefEmitter.cpp
index b76ba05954aa5..edb1a4d5d8531 100644
--- a/llvm/utils/TableGen/RISCVTargetDefEmitter.cpp
+++ b/llvm/utils/TableGen/RISCVTargetDefEmitter.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/Support/RISCVISAUtils.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/TableGenBackend.h"
@@ -210,10 +211,46 @@ static void emitRISCVProcs(RecordKeeper &RK, raw_ostream &OS) {
   OS << "\n#undef TUNE_PROC\n";
 }
 
+static void emitRISCVExtensionBitmask(RecordKeeper &RK, raw_ostream &OS) {
+
+  std::vector<Record *> Extensions =
+      RK.getAllDerivedDefinitionsIfDefined("RISCVExtensionBitmask");
+  llvm::sort(Extensions, [](const Record *Rec1, const Record *Rec2) {
+    return getExtensionName(Rec1) < getExtensionName(Rec2);
+  });
+
+#ifndef NDEBUG
+  llvm::DenseSet<std::pair<uint64_t, uint64_t>> Seen;
+#endif
+
+  OS << "#ifdef GET_RISCVExtensionBitmaskTable_IMPL\n";
+  OS << "static const RISCVExtensionBitmask ExtensionBitmask[]={\n";
+  for (const Record *Rec : Extensions) {
+    unsigned GroupIDVal = Rec->getValueAsInt("GroupID");
+    unsigned BitPosVal = Rec->getValueAsInt("BitPos");
+
+    StringRef ExtName = Rec->getValueAsString("Name");
+    ExtName.consume_front("experimental-");
+
+#ifndef NDEBUG
+    assert(Seen.insert(std::make_pair(GroupIDVal, BitPosVal)).second &&
+           "duplicated bitmask");
+#endif
+
+    OS << "    {"
+       << "\"" << ExtName << "\""
+       << ", " << GroupIDVal << ", " << BitPosVal << "ULL"
+       << "},\n";
+  }
+  OS << "};\n";
+  OS << "#endif\n";
+}
+
 static void EmitRISCVTargetDef(RecordKeeper &RK, raw_ostream &OS) {
   emitRISCVExtensions(RK, OS);
   emitRISCVProfiles(RK, OS);
   emitRISCVProcs(RK, OS);
+  emitRISCVExtensionBitmask(RK, OS);
 }
 
 static TableGen::Emitter::Opt X("gen-riscv-target-def", EmitRISCVTargetDef,

>From 205f27e3261a3ba30b608e399f93ab6e8c03b3dd Mon Sep 17 00:00:00 2001
From: Piyou Chen <piyou.chen at sifive.com>
Date: Thu, 11 Jul 2024 20:48:02 -0700
Subject: [PATCH 2/4] Add zihintpause

---
 llvm/lib/Target/RISCV/RISCVFeatures.td | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
index 125e9e2f53953..ff6ec42a2e72f 100644
--- a/llvm/lib/Target/RISCV/RISCVFeatures.td
+++ b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -139,7 +139,8 @@ def HasStdExtZifencei : Predicate<"Subtarget->hasStdExtZifencei()">,
 
 def FeatureStdExtZihintpause
     : RISCVExtension<"zihintpause", 2, 0,
-                     "'Zihintpause' (Pause Hint)">;
+                     "'Zihintpause' (Pause Hint)">,
+      RISCVExtensionBitmask<0, 40>;
 def HasStdExtZihintpause : Predicate<"Subtarget->hasStdExtZihintpause()">,
                            AssemblerPredicate<(all_of FeatureStdExtZihintpause),
                                               "'Zihintpause' (Pause Hint)">;

>From 0a873d0897fbbf94d46e6fbf129aee3090b4b9c1 Mon Sep 17 00:00:00 2001
From: Piyou Chen <piyou.chen at sifive.com>
Date: Mon, 10 Jun 2024 22:22:42 -0700
Subject: [PATCH 3/4] [RISCV][FMV] Support target_clones

---
 .../clang/Basic/DiagnosticFrontendKinds.td    |   4 +
 clang/include/clang/Basic/TargetInfo.h        |   3 +-
 clang/lib/AST/ASTContext.cpp                  |  12 +
 clang/lib/CodeGen/CGBuiltin.cpp               |  78 +++++++
 clang/lib/CodeGen/CodeGenFunction.cpp         |  91 +++++++-
 clang/lib/CodeGen/CodeGenFunction.h           |   7 +
 clang/lib/CodeGen/CodeGenModule.cpp           |   5 +-
 clang/lib/CodeGen/Targets/RISCV.cpp           |  23 ++
 clang/lib/Sema/SemaDeclAttr.cpp               |  26 +++
 .../attr-target-clones-riscv-invaild.c        |   8 +
 clang/test/CodeGen/attr-target-clones-riscv.c | 205 ++++++++++++++++++
 .../CodeGenCXX/attr-target-clones-riscv.cpp   | 204 +++++++++++++++++
 .../test/SemaCXX/attr-target-clones-riscv.cpp |  32 +++
 .../llvm/TargetParser/RISCVTargetParser.h     |   4 +
 llvm/lib/TargetParser/RISCVTargetParser.cpp   |  18 +-
 15 files changed, 715 insertions(+), 5 deletions(-)
 create mode 100644 clang/test/CodeGen/attr-target-clones-riscv-invaild.c
 create mode 100644 clang/test/CodeGen/attr-target-clones-riscv.c
 create mode 100644 clang/test/CodeGenCXX/attr-target-clones-riscv.cpp
 create mode 100644 clang/test/SemaCXX/attr-target-clones-riscv.cpp

diff --git a/clang/include/clang/Basic/DiagnosticFrontendKinds.td b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
index 12a4617c64d87..b2b63674ecc07 100644
--- a/clang/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -375,4 +375,8 @@ def warn_missing_symbol_graph_dir : Warning<
 def err_ast_action_on_llvm_ir : Error<
   "cannot apply AST actions to LLVM IR file '%0'">,
   DefaultFatal;
+
+def err_os_unsupport_riscv_target_clones : Error<
+  "target_clones is currently only supported on Linux">;
+
 }
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index cf7628553647c..40fbc3a1116cb 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -1519,7 +1519,8 @@ class TargetInfo : public TransferrableTargetInfo,
   /// Identify whether this target supports multiversioning of functions,
   /// which requires support for cpu_supports and cpu_is functionality.
   bool supportsMultiVersioning() const {
-    return getTriple().isX86() || getTriple().isAArch64();
+    return getTriple().isX86() || getTriple().isAArch64() ||
+           getTriple().isRISCV();
   }
 
   /// Identify whether this target supports IFuncs.
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 8e35e71d4a23e..29dce55f349ec 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -13839,6 +13839,18 @@ void ASTContext::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
                       Target->getTargetOpts().FeaturesAsWritten.begin(),
                       Target->getTargetOpts().FeaturesAsWritten.end());
       Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Features);
+    } else if (Target->getTriple().isRISCV()) {
+      StringRef VersionStr = TC->getFeatureStr(GD.getMultiVersionIndex());
+      std::vector<std::string> Features;
+      if (VersionStr != "default") {
+        ParsedTargetAttr ParsedAttr = Target->parseTargetAttr(VersionStr);
+        Features.insert(Features.begin(), ParsedAttr.Features.begin(),
+                        ParsedAttr.Features.end());
+      }
+      Features.insert(Features.begin(),
+                      Target->getTargetOpts().FeaturesAsWritten.begin(),
+                      Target->getTargetOpts().FeaturesAsWritten.end());
+      Target->initFeatureMap(FeatureMap, getDiagnostics(), TargetCPU, Features);
     } else {
       std::vector<std::string> Features;
       StringRef VersionStr = TC->getFeatureStr(GD.getMultiVersionIndex());
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 6cc0d9485720c..42647224a88a4 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -62,6 +62,7 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/ScopedPrinter.h"
 #include "llvm/TargetParser/AArch64TargetParser.h"
+#include "llvm/TargetParser/RISCVTargetParser.h"
 #include "llvm/TargetParser/X86TargetParser.h"
 #include <optional>
 #include <sstream>
@@ -14214,6 +14215,16 @@ Value *CodeGenFunction::EmitAArch64CpuInit() {
   return Builder.CreateCall(Func);
 }
 
+Value *CodeGenFunction::EmitRISCVCpuInit() {
+  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
+  llvm::FunctionCallee Func =
+      CGM.CreateRuntimeFunction(FTy, "__init_riscv_features_bit");
+  cast<llvm::GlobalValue>(Func.getCallee())->setDSOLocal(true);
+  cast<llvm::GlobalValue>(Func.getCallee())
+      ->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
+  return Builder.CreateCall(Func);
+}
+
 Value *CodeGenFunction::EmitX86CpuInit() {
   llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy,
                                                     /*Variadic*/ false);
@@ -14266,6 +14277,73 @@ CodeGenFunction::EmitAArch64CpuSupports(ArrayRef<StringRef> FeaturesStrs) {
   return Result;
 }
 
+Value *CodeGenFunction::EmitRISCVCpuSupports(ArrayRef<StringRef> FeaturesStrs,
+                                             unsigned &MaxGroupIDUsed) {
+
+  const unsigned FeatureBitSize = llvm::RISCV::RISCVFeatureBitSize;
+  llvm::ArrayType *ArrayOfInt64Ty =
+      llvm::ArrayType::get(Int64Ty, FeatureBitSize);
+  llvm::Type *StructTy = llvm::StructType::get(Int32Ty, ArrayOfInt64Ty);
+  llvm::Constant *RISCVFeaturesBits =
+      CGM.CreateRuntimeVariable(StructTy, "__riscv_feature_bits");
+  cast<llvm::GlobalValue>(RISCVFeaturesBits)->setDSOLocal(true);
+
+  auto LoadFeatureBit = [&](unsigned Index) {
+    // Create GEP then load.
+    Value *IndexVal = llvm::ConstantInt::get(Int32Ty, Index);
+    std::vector<llvm::Value *> GEPIndices = {llvm::ConstantInt::get(Int32Ty, 0),
+                                             llvm::ConstantInt::get(Int32Ty, 1),
+                                             IndexVal};
+    Value *Ptr =
+        Builder.CreateInBoundsGEP(StructTy, RISCVFeaturesBits, GEPIndices);
+    Value *FeaturesBit =
+        Builder.CreateAlignedLoad(Int64Ty, Ptr, CharUnits::fromQuantity(8));
+    return FeaturesBit;
+  };
+
+  SmallVector<unsigned long long> RequireFeatureBits =
+      llvm::RISCV::getRequireFeatureBitMask(FeaturesStrs);
+  Value *Result = Builder.getTrue();
+  for (unsigned i = 0; i < RequireFeatureBits.size(); i++) {
+    if (!RequireFeatureBits[i])
+      continue;
+    MaxGroupIDUsed = i;
+    Value *Mask = Builder.getInt64(RequireFeatureBits[i]);
+    Value *Bitset = Builder.CreateAnd(LoadFeatureBit(i), Mask);
+    Value *Cmp = Builder.CreateICmpEQ(Bitset, Mask);
+    Result = Builder.CreateAnd(Result, Cmp);
+  }
+
+  return Result;
+}
+
+Value *CodeGenFunction::EmitRISCVFeatureBitsLength(unsigned MaxGroupIDUsed) {
+
+  const unsigned FeatureBitSize = llvm::RISCV::RISCVFeatureBitSize;
+  llvm::ArrayType *ArrayOfInt64Ty =
+      llvm::ArrayType::get(Int64Ty, FeatureBitSize);
+  llvm::Type *StructTy = llvm::StructType::get(Int32Ty, ArrayOfInt64Ty);
+  llvm::Constant *RISCVFeaturesBits =
+      CGM.CreateRuntimeVariable(StructTy, "__riscv_feature_bits");
+  cast<llvm::GlobalValue>(RISCVFeaturesBits)->setDSOLocal(true);
+
+  auto LoadMaxGroupID = [&]() {
+    std::vector<llvm::Value *> GEPIndices = {
+        llvm::ConstantInt::get(Int32Ty, 0), llvm::ConstantInt::get(Int32Ty, 0)};
+    llvm::Value *Ptr =
+        Builder.CreateInBoundsGEP(StructTy, RISCVFeaturesBits, GEPIndices);
+    Value *Length =
+        Builder.CreateAlignedLoad(Int64Ty, Ptr, CharUnits::fromQuantity(8));
+    return Length;
+  };
+
+  Value *UsedMaxGroupID = Builder.getInt64(MaxGroupIDUsed);
+  Value *GroupIDResult =
+      Builder.CreateICmpULT(UsedMaxGroupID, LoadMaxGroupID());
+
+  return GroupIDResult;
+}
+
 Value *CodeGenFunction::EmitX86BuiltinExpr(unsigned BuiltinID,
                                            const CallExpr *E) {
   if (BuiltinID == Builtin::BI__builtin_cpu_is)
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 26deeca95d326..27305e0f4b7b4 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -2854,10 +2854,99 @@ void CodeGenFunction::EmitMultiVersionResolver(
   case llvm::Triple::aarch64:
     EmitAArch64MultiVersionResolver(Resolver, Options);
     return;
+  case llvm::Triple::riscv32:
+  case llvm::Triple::riscv64:
+    EmitRISCVMultiVersionResolver(Resolver, Options);
+    return;
 
   default:
-    assert(false && "Only implemented for x86 and AArch64 targets");
+    assert(false && "Only implemented for x86, AArch64 and RISC-V targets");
+  }
+}
+
+void CodeGenFunction::EmitRISCVMultiVersionResolver(
+    llvm::Function *Resolver, ArrayRef<MultiVersionResolverOption> Options) {
+
+  if (getContext().getTargetInfo().getTriple().getOS() !=
+      llvm::Triple::OSType::Linux) {
+    CGM.getDiags().Report(diag::err_os_unsupport_riscv_target_clones);
+    return;
+  }
+
+  llvm::BasicBlock *CurBlock = createBasicBlock("resolver_entry", Resolver);
+  Builder.SetInsertPoint(CurBlock);
+  EmitRISCVCpuInit();
+
+  bool SupportsIFunc = getContext().getTargetInfo().supportsIFunc();
+  bool HasDefault = false;
+  int DefaultIndex = 0;
+  // Check the each candidate function.
+  for (unsigned Index = 0; Index < Options.size(); Index++) {
+
+    if (Options[Index].Conditions.Features[0].starts_with("default")) {
+      HasDefault = true;
+      DefaultIndex = Index;
+      continue;
+    }
+
+    Builder.SetInsertPoint(CurBlock);
+
+    std::vector<std::string> TargetAttrFeats =
+        getContext()
+            .getTargetInfo()
+            .parseTargetAttr(Options[Index].Conditions.Features[0])
+            .Features;
+
+    if (!TargetAttrFeats.empty()) {
+
+      llvm::BasicBlock *SecondCond =
+          createBasicBlock("resovler_cond", Resolver);
+
+      Builder.SetInsertPoint(SecondCond);
+      unsigned MaxGroupIDUsed = 0;
+      llvm::SmallVector<StringRef, 8> CurrTargetAttrFeats;
+
+      for (auto Feat: TargetAttrFeats)
+        CurrTargetAttrFeats.push_back(StringRef(Feat).substr(1));
+      
+      llvm::Value *SecondCondition =
+          EmitRISCVCpuSupports(CurrTargetAttrFeats, MaxGroupIDUsed);
+
+      Builder.SetInsertPoint(CurBlock);
+      llvm::Value *FirstCondition = EmitRISCVFeatureBitsLength(MaxGroupIDUsed);
+
+      llvm::BasicBlock *RetBlock =
+          createBasicBlock("resolver_return", Resolver);
+      CGBuilderTy RetBuilder(*this, RetBlock);
+      CreateMultiVersionResolverReturn(CGM, Resolver, RetBuilder,
+                                       Options[Index].Function, SupportsIFunc);
+      llvm::BasicBlock *ElseBlock = createBasicBlock("resolver_else", Resolver);
+
+      Builder.SetInsertPoint(CurBlock);
+      Builder.CreateCondBr(FirstCondition, SecondCond, ElseBlock);
+
+      Builder.SetInsertPoint(SecondCond);
+      Builder.CreateCondBr(SecondCondition, RetBlock, ElseBlock);
+
+      CurBlock = ElseBlock;
+    }
   }
+
+  // Finally, emit the default one.
+  if (HasDefault) {
+    Builder.SetInsertPoint(CurBlock);
+    CreateMultiVersionResolverReturn(
+        CGM, Resolver, Builder, Options[DefaultIndex].Function, SupportsIFunc);
+    return;
+  }
+
+  // If no generic/default, emit an unreachable.
+  Builder.SetInsertPoint(CurBlock);
+  llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
+  TrapCall->setDoesNotReturn();
+  TrapCall->setDoesNotThrow();
+  Builder.CreateUnreachable();
+  Builder.ClearInsertionPoint();
 }
 
 void CodeGenFunction::EmitAArch64MultiVersionResolver(
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 13f12b5d878a6..107701d3f1faa 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -5291,6 +5291,9 @@ class CodeGenFunction : public CodeGenTypeCache {
   void
   EmitAArch64MultiVersionResolver(llvm::Function *Resolver,
                                   ArrayRef<MultiVersionResolverOption> Options);
+  void
+  EmitRISCVMultiVersionResolver(llvm::Function *Resolver,
+                                ArrayRef<MultiVersionResolverOption> Options);
 
 private:
   QualType getVarArgType(const Expr *Arg);
@@ -5315,6 +5318,10 @@ class CodeGenFunction : public CodeGenTypeCache {
   FormAArch64ResolverCondition(const MultiVersionResolverOption &RO);
   llvm::Value *EmitAArch64CpuSupports(const CallExpr *E);
   llvm::Value *EmitAArch64CpuSupports(ArrayRef<StringRef> FeatureStrs);
+  llvm::Value *EmitRISCVCpuInit();
+  llvm::Value *EmitRISCVCpuSupports(ArrayRef<StringRef> FeatureStrs,
+                                    unsigned &MaxGroupIDUsed);
+  llvm::Value *EmitRISCVFeatureBitsLength(unsigned MaxGroupIDUsed);
 };
 
 inline DominatingLLVMValue::saved_type
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 5c810cd332185..d876dff3d5755 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -4257,7 +4257,10 @@ void CodeGenModule::emitMultiVersionFunctions() {
               Feats.clear();
               if (getTarget().getTriple().isAArch64())
                 TC->getFeatures(Feats, I);
-              else {
+              else if (getTarget().getTriple().isRISCV()) {
+                StringRef Version = TC->getFeatureStr(I);
+                Feats.push_back(Version);
+              } else {
                 StringRef Version = TC->getFeatureStr(I);
                 if (Version.starts_with("arch="))
                   Architecture = Version.drop_front(sizeof("arch=") - 1);
diff --git a/clang/lib/CodeGen/Targets/RISCV.cpp b/clang/lib/CodeGen/Targets/RISCV.cpp
index f2add9351c03c..ba81bf7d1dd0a 100644
--- a/clang/lib/CodeGen/Targets/RISCV.cpp
+++ b/clang/lib/CodeGen/Targets/RISCV.cpp
@@ -63,9 +63,32 @@ class RISCVABIInfo : public DefaultABIInfo {
                                                CharUnits Field2Off) const;
 
   ABIArgInfo coerceVLSVector(QualType Ty) const;
+
+  using ABIInfo::appendAttributeMangling;
+  void appendAttributeMangling(TargetClonesAttr *Attr, unsigned Index,
+                               raw_ostream &Out) const override;
+  void appendAttributeMangling(StringRef AttrStr,
+                               raw_ostream &Out) const override;
 };
 } // end anonymous namespace
 
+void RISCVABIInfo::appendAttributeMangling(TargetClonesAttr *Attr,
+                                           unsigned Index,
+                                           raw_ostream &Out) const {
+  appendAttributeMangling(Attr->getFeatureStr(Index), Out);
+}
+
+void RISCVABIInfo::appendAttributeMangling(StringRef AttrStr,
+                                           raw_ostream &Out) const {
+  if (AttrStr == "default") {
+    Out << ".default";
+    return;
+  }
+
+  Out << '.';
+  Out << AttrStr;
+}
+
 void RISCVABIInfo::computeInfo(CGFunctionInfo &FI) const {
   QualType RetTy = FI.getReturnType();
   if (!getCXXABI().classifyReturnType(FI))
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index f2cd46d1e7c93..9b420f90b222f 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3127,6 +3127,32 @@ bool Sema::checkTargetClonesAttrString(
                                  /*IncludeLocallyStreaming=*/false))
         return Diag(LiteralLoc,
                     diag::err_sme_streaming_cannot_be_multiversioned);
+    } else if (TInfo.getTriple().isRISCV()) {
+      // Suppress warn_target_clone_mixed_values
+      HasCommas = false;
+
+      // Only support arch=+ext,... syntax.
+      if (Str.starts_with("arch=+")) {
+        // parseTargetAttr will parse full version string,
+        // the following split Cur string is no longer interesting.
+        if ((!Cur.starts_with("arch=")))
+          continue;
+
+        ParsedTargetAttr TargetAttr =
+            Context.getTargetInfo().parseTargetAttr(Str);
+        if (TargetAttr.Features.empty())
+          return Diag(CurLoc, diag::warn_unsupported_target_attribute)
+                 << Unsupported << None << Str << TargetClones;
+      } else if (Str == "default") {
+        DefaultIsDupe = HasDefault;
+        HasDefault = true;
+      } else {
+        return Diag(CurLoc, diag::warn_unsupported_target_attribute)
+               << Unsupported << None << Str << TargetClones;
+      }
+      if (llvm::is_contained(StringsBuffer, Str) || DefaultIsDupe)
+        Diag(CurLoc, diag::warn_target_clone_duplicate_options);
+      StringsBuffer.push_back(Str);
     } else {
       // Other targets ( currently X86 )
       if (Cur.starts_with("arch=")) {
diff --git a/clang/test/CodeGen/attr-target-clones-riscv-invaild.c b/clang/test/CodeGen/attr-target-clones-riscv-invaild.c
new file mode 100644
index 0000000000000..f5e8f40d7a8f3
--- /dev/null
+++ b/clang/test/CodeGen/attr-target-clones-riscv-invaild.c
@@ -0,0 +1,8 @@
+// RUN: not %clang_cc1 -triple riscv64 -target-feature +i -emit-llvm -o - %s 2>&1 | FileCheck %s --check-prefix=CHECK-UNSUPPORT-OS
+
+// CHECK-UNSUPPORT-OS: error: target_clones is currently only supported on Linux
+__attribute__((target_clones("default", "arch=+c"))) int foo2(void) {
+  return 2;
+}
+
+int bar() { return foo1()+foo2(); }
diff --git a/clang/test/CodeGen/attr-target-clones-riscv.c b/clang/test/CodeGen/attr-target-clones-riscv.c
new file mode 100644
index 0000000000000..1088dd56a4d83
--- /dev/null
+++ b/clang/test/CodeGen/attr-target-clones-riscv.c
@@ -0,0 +1,205 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals all --include-generated-funcs --version 4
+// RUN: %clang_cc1 -triple riscv64-linux-gnu -target-feature +i -emit-llvm -o - %s | FileCheck %s
+
+__attribute__((target_clones("default", "arch=+m"))) int foo1(void) {
+  return 1;
+}
+__attribute__((target_clones("default", "arch=+zbb", "arch=+m"))) int foo2(void) { return 2; }
+__attribute__((target_clones("default", "arch=+zbb,+c"))) int foo3(void) { return 3; }
+__attribute__((target_clones("default", "arch=+zbb,+v"))) int
+foo4(void) {
+  return 4;
+}
+__attribute__((target_clones("default"))) int foo5(void) { return 5; }
+__attribute__((target_clones("default", "arch=+zvkt"))) int foo6(void) { return 2; }
+
+int bar() { return foo1() + foo2() + foo3() + foo4() + foo5(); }
+
+//.
+// CHECK: @__riscv_feature_bits = external dso_local global { i32, [1 x i64] }
+// CHECK: @foo1.ifunc = weak_odr alias i32 (), ptr @foo1
+// CHECK: @foo2.ifunc = weak_odr alias i32 (), ptr @foo2
+// CHECK: @foo3.ifunc = weak_odr alias i32 (), ptr @foo3
+// CHECK: @foo4.ifunc = weak_odr alias i32 (), ptr @foo4
+// CHECK: @foo5.ifunc = weak_odr alias i32 (), ptr @foo5
+// CHECK: @foo6.ifunc = weak_odr alias i32 (), ptr @foo6
+// CHECK: @foo1 = weak_odr ifunc i32 (), ptr @foo1.resolver
+// CHECK: @foo2 = weak_odr ifunc i32 (), ptr @foo2.resolver
+// CHECK: @foo3 = weak_odr ifunc i32 (), ptr @foo3.resolver
+// CHECK: @foo4 = weak_odr ifunc i32 (), ptr @foo4.resolver
+// CHECK: @foo5 = weak_odr ifunc i32 (), ptr @foo5.resolver
+// CHECK: @foo6 = weak_odr ifunc i32 (), ptr @foo6.resolver
+//.
+// CHECK-LABEL: define dso_local signext i32 @foo1.default(
+// CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK-LABEL: define weak_odr ptr @foo1.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 4096
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 4096
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"foo1.arch=+m"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @foo1.default
+//
+//
+// CHECK-LABEL: define dso_local signext i32 @foo2.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK-LABEL: define weak_odr ptr @foo2.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 268435456
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 268435456
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"foo2.arch=+zbb"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP6:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP7:%.*]] = icmp ult i64 0, [[TMP6]]
+// CHECK-NEXT:    br i1 [[TMP7]], label [[RESOVLER_COND1:%.*]], label [[RESOLVER_ELSE3:%.*]]
+// CHECK:       resovler_cond1:
+// CHECK-NEXT:    [[TMP8:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP9:%.*]] = and i64 [[TMP8]], 4096
+// CHECK-NEXT:    [[TMP10:%.*]] = icmp eq i64 [[TMP9]], 4096
+// CHECK-NEXT:    [[TMP11:%.*]] = and i1 true, [[TMP10]]
+// CHECK-NEXT:    br i1 [[TMP11]], label [[RESOLVER_RETURN2:%.*]], label [[RESOLVER_ELSE3]]
+// CHECK:       resolver_return2:
+// CHECK-NEXT:    ret ptr @"foo2.arch=+m"
+// CHECK:       resolver_else3:
+// CHECK-NEXT:    ret ptr @foo2.default
+//
+//
+// CHECK-LABEL: define dso_local signext i32 @foo3.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 3
+//
+//
+// CHECK-LABEL: define weak_odr ptr @foo3.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 12
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 12
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"foo3.arch=+zbb,+c"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @foo3.default
+//
+//
+// CHECK-LABEL: define dso_local signext i32 @foo4.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 4
+//
+//
+// CHECK-LABEL: define weak_odr ptr @foo4.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 69206016
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 69206016
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"foo4.arch=+zbb,+v"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @foo4.default
+//
+//
+// CHECK-LABEL: define dso_local signext i32 @foo5.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 5
+//
+//
+// CHECK-LABEL: define weak_odr ptr @foo5.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    ret ptr @foo5.default
+//
+//
+// CHECK-LABEL: define dso_local signext i32 @foo6.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK-LABEL: define weak_odr ptr @foo6.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 576460752303423488
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 576460752303423488
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"foo6.arch=+zvkt"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @foo6.default
+//
+//
+// CHECK-LABEL: define dso_local signext i32 @bar(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = call signext i32 @foo1()
+// CHECK-NEXT:    [[CALL1:%.*]] = call signext i32 @foo2()
+// CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 [[CALL]], [[CALL1]]
+// CHECK-NEXT:    [[CALL2:%.*]] = call signext i32 @foo3()
+// CHECK-NEXT:    [[ADD3:%.*]] = add nsw i32 [[ADD]], [[CALL2]]
+// CHECK-NEXT:    [[CALL4:%.*]] = call signext i32 @foo4()
+// CHECK-NEXT:    [[ADD5:%.*]] = add nsw i32 [[ADD3]], [[CALL4]]
+// CHECK-NEXT:    [[CALL6:%.*]] = call signext i32 @foo5()
+// CHECK-NEXT:    [[ADD7:%.*]] = add nsw i32 [[ADD5]], [[CALL6]]
+// CHECK-NEXT:    ret i32 [[ADD7]]
+//
+//.
+// CHECK: attributes #[[ATTR0]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+i" }
+// CHECK: attributes #[[ATTR1:[0-9]+]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+i,+m,+zmmul" }
+// CHECK: attributes #[[ATTR2:[0-9]+]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+i,+zbb" }
+// CHECK: attributes #[[ATTR3:[0-9]+]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+c,+i,+zbb" }
+// CHECK: attributes #[[ATTR4:[0-9]+]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+d,+f,+i,+v,+zbb,+zicsr,+zve32f,+zve32x,+zve64d,+zve64f,+zve64x,+zvl128b,+zvl32b,+zvl64b" }
+// CHECK: attributes #[[ATTR5:[0-9]+]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+i,+zvkt" }
+//.
+// CHECK: [[META0:![0-9]+]] = !{i32 1, !"wchar_size", i32 4}
+// CHECK: [[META1:![0-9]+]] = !{i32 1, !"target-abi", !"lp64"}
+// CHECK: [[META2:![0-9]+]] = !{i32 6, !"riscv-isa", [[META3:![0-9]+]]}
+// CHECK: [[META3]] = !{!"rv64i2p1"}
+// CHECK: [[META4:![0-9]+]] = !{i32 8, !"SmallDataLimit", i32 0}
+// CHECK: [[META5:![0-9]+]] = !{!"{{.*}}clang version {{.*}}"}
+//.
diff --git a/clang/test/CodeGenCXX/attr-target-clones-riscv.cpp b/clang/test/CodeGenCXX/attr-target-clones-riscv.cpp
new file mode 100644
index 0000000000000..73bbfcd8b9652
--- /dev/null
+++ b/clang/test/CodeGenCXX/attr-target-clones-riscv.cpp
@@ -0,0 +1,204 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals all --include-generated-funcs --version 4
+// RUN: %clang_cc1 -std=c++11 -triple riscv64-linux-gnu -target-feature +i -target-feature +m -emit-llvm %s -o - | FileCheck %s
+
+__attribute__((target_clones("default", "arch=+m"))) int foo1(void) {
+  return 1;
+}
+__attribute__((target_clones("default", "arch=+zbb", "arch=+m"))) int foo2(void) { return 2; }
+__attribute__((target_clones("default", "arch=+zbb,+c"))) int foo3(void) { return 3; }
+__attribute__((target_clones("default", "arch=+zbb,+v"))) int
+foo4(void) {
+  return 4;
+}
+__attribute__((target_clones("default"))) int foo5(void) { return 5; }
+__attribute__((target_clones("default", "arch=+zvkt"))) int foo6(void) { return 2; }
+
+int bar() { return foo1() + foo2() + foo3() + foo4() + foo5(); }
+
+//.
+// CHECK: @__riscv_feature_bits = external dso_local global { i32, [1 x i64] }
+// CHECK: @_Z4foo1v.ifunc = weak_odr alias i32 (), ptr @_Z4foo1v
+// CHECK: @_Z4foo2v.ifunc = weak_odr alias i32 (), ptr @_Z4foo2v
+// CHECK: @_Z4foo3v.ifunc = weak_odr alias i32 (), ptr @_Z4foo3v
+// CHECK: @_Z4foo4v.ifunc = weak_odr alias i32 (), ptr @_Z4foo4v
+// CHECK: @_Z4foo5v.ifunc = weak_odr alias i32 (), ptr @_Z4foo5v
+// CHECK: @_Z4foo6v.ifunc = weak_odr alias i32 (), ptr @_Z4foo6v
+// CHECK: @_Z4foo1v = weak_odr ifunc i32 (), ptr @_Z4foo1v.resolver
+// CHECK: @_Z4foo2v = weak_odr ifunc i32 (), ptr @_Z4foo2v.resolver
+// CHECK: @_Z4foo3v = weak_odr ifunc i32 (), ptr @_Z4foo3v.resolver
+// CHECK: @_Z4foo4v = weak_odr ifunc i32 (), ptr @_Z4foo4v.resolver
+// CHECK: @_Z4foo5v = weak_odr ifunc i32 (), ptr @_Z4foo5v.resolver
+// CHECK: @_Z4foo6v = weak_odr ifunc i32 (), ptr @_Z4foo6v.resolver
+//.
+// CHECK-LABEL: define dso_local noundef signext i32 @_Z4foo1v.default(
+// CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK-LABEL: define weak_odr ptr @_Z4foo1v.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 4096
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 4096
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"_Z4foo1v.arch=+m"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @_Z4foo1v.default
+//
+//
+// CHECK-LABEL: define dso_local noundef signext i32 @_Z4foo2v.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK-LABEL: define weak_odr ptr @_Z4foo2v.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 268435456
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 268435456
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"_Z4foo2v.arch=+zbb"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP6:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP7:%.*]] = icmp ult i64 0, [[TMP6]]
+// CHECK-NEXT:    br i1 [[TMP7]], label [[RESOVLER_COND1:%.*]], label [[RESOLVER_ELSE3:%.*]]
+// CHECK:       resovler_cond1:
+// CHECK-NEXT:    [[TMP8:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP9:%.*]] = and i64 [[TMP8]], 4096
+// CHECK-NEXT:    [[TMP10:%.*]] = icmp eq i64 [[TMP9]], 4096
+// CHECK-NEXT:    [[TMP11:%.*]] = and i1 true, [[TMP10]]
+// CHECK-NEXT:    br i1 [[TMP11]], label [[RESOLVER_RETURN2:%.*]], label [[RESOLVER_ELSE3]]
+// CHECK:       resolver_return2:
+// CHECK-NEXT:    ret ptr @"_Z4foo2v.arch=+m"
+// CHECK:       resolver_else3:
+// CHECK-NEXT:    ret ptr @_Z4foo2v.default
+//
+//
+// CHECK-LABEL: define dso_local noundef signext i32 @_Z4foo3v.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 3
+//
+//
+// CHECK-LABEL: define weak_odr ptr @_Z4foo3v.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 12
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 12
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"_Z4foo3v.arch=+zbb,+c"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @_Z4foo3v.default
+//
+//
+// CHECK-LABEL: define dso_local noundef signext i32 @_Z4foo4v.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 4
+//
+//
+// CHECK-LABEL: define weak_odr ptr @_Z4foo4v.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 69206016
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 69206016
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"_Z4foo4v.arch=+zbb,+v"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @_Z4foo4v.default
+//
+//
+// CHECK-LABEL: define dso_local noundef signext i32 @_Z4foo5v.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 5
+//
+//
+// CHECK-LABEL: define weak_odr ptr @_Z4foo5v.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    ret ptr @_Z4foo5v.default
+//
+//
+// CHECK-LABEL: define dso_local noundef signext i32 @_Z4foo6v.default(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK-LABEL: define weak_odr ptr @_Z4foo6v.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    call void @__init_riscv_features_bit()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__riscv_feature_bits, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 0, [[TMP0]]
+// CHECK-NEXT:    br i1 [[TMP1]], label [[RESOVLER_COND:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       resovler_cond:
+// CHECK-NEXT:    [[TMP2:%.*]] = load i64, ptr getelementptr inbounds ({ i32, [1 x i64] }, ptr @__riscv_feature_bits, i32 0, i32 1, i32 0), align 8
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], 576460752303423488
+// CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[TMP3]], 576460752303423488
+// CHECK-NEXT:    [[TMP5:%.*]] = and i1 true, [[TMP4]]
+// CHECK-NEXT:    br i1 [[TMP5]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE]]
+// CHECK:       resolver_return:
+// CHECK-NEXT:    ret ptr @"_Z4foo6v.arch=+zvkt"
+// CHECK:       resolver_else:
+// CHECK-NEXT:    ret ptr @_Z4foo6v.default
+//
+//
+// CHECK-LABEL: define dso_local noundef signext i32 @_Z3barv(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = call noundef signext i32 @_Z4foo1v()
+// CHECK-NEXT:    [[CALL1:%.*]] = call noundef signext i32 @_Z4foo2v()
+// CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 [[CALL]], [[CALL1]]
+// CHECK-NEXT:    [[CALL2:%.*]] = call noundef signext i32 @_Z4foo3v()
+// CHECK-NEXT:    [[ADD3:%.*]] = add nsw i32 [[ADD]], [[CALL2]]
+// CHECK-NEXT:    [[CALL4:%.*]] = call noundef signext i32 @_Z4foo4v()
+// CHECK-NEXT:    [[ADD5:%.*]] = add nsw i32 [[ADD3]], [[CALL4]]
+// CHECK-NEXT:    [[CALL6:%.*]] = call noundef signext i32 @_Z4foo5v()
+// CHECK-NEXT:    [[ADD7:%.*]] = add nsw i32 [[ADD5]], [[CALL6]]
+// CHECK-NEXT:    ret i32 [[ADD7]]
+//
+//.
+// CHECK: attributes #[[ATTR0]] = { mustprogress noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+i,+m,+zmmul" }
+// CHECK: attributes #[[ATTR1:[0-9]+]] = { mustprogress noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+i,+m,+zbb,+zmmul" }
+// CHECK: attributes #[[ATTR2:[0-9]+]] = { mustprogress noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+c,+i,+m,+zbb,+zmmul" }
+// CHECK: attributes #[[ATTR3:[0-9]+]] = { mustprogress noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+d,+f,+i,+m,+v,+zbb,+zicsr,+zmmul,+zve32f,+zve32x,+zve64d,+zve64f,+zve64x,+zvl128b,+zvl32b,+zvl64b" }
+// CHECK: attributes #[[ATTR4:[0-9]+]] = { mustprogress noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+i,+m,+zmmul,+zvkt" }
+//.
+// CHECK: [[META0:![0-9]+]] = !{i32 1, !"wchar_size", i32 4}
+// CHECK: [[META1:![0-9]+]] = !{i32 1, !"target-abi", !"lp64"}
+// CHECK: [[META2:![0-9]+]] = !{i32 6, !"riscv-isa", [[META3:![0-9]+]]}
+// CHECK: [[META3]] = !{!"rv64i2p1_m2p0_zmmul1p0"}
+// CHECK: [[META4:![0-9]+]] = !{i32 8, !"SmallDataLimit", i32 0}
+// CHECK: [[META5:![0-9]+]] = !{!"{{.*}}clang version {{.*}}"}
+//.
diff --git a/clang/test/SemaCXX/attr-target-clones-riscv.cpp b/clang/test/SemaCXX/attr-target-clones-riscv.cpp
new file mode 100644
index 0000000000000..edee5f7c231e9
--- /dev/null
+++ b/clang/test/SemaCXX/attr-target-clones-riscv.cpp
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -triple riscv64-linux-gnu  -fsyntax-only -verify -fexceptions -fcxx-exceptions %s -std=c++14
+
+// expected-warning at +1 {{unsupported 'mcpu=sifive-u74' in the 'target_clones' attribute string; 'target_clones' attribute ignored}}
+void __attribute__((target_clones("default", "mcpu=sifive-u74"))) mcpu() {}
+
+// expected-warning at +1 {{unsupported 'mtune=sifive-u74' in the 'target_clones' attribute string; 'target_clones' attribute ignored}}
+void __attribute__((target_clones("default", "mtune=sifive-u74"))) mtune() {}
+
+// expected-warning at +1 {{version list contains duplicate entries}}
+void __attribute__((target_clones("default", "arch=+c", "arch=+c"))) dupVersion() {}
+
+// expected-warning at +1 {{unsupported '' in the 'target_clones' attribute string; 'target_clones' attribute ignored}}
+void __attribute__((target_clones("default", ""))) emptyVersion() {}
+
+// expected-error at +1 {{'target_clones' multiversioning requires a default target}}
+void __attribute__((target_clones("arch=+c"))) withoutDefault() {}
+
+// expected-warning at +1 {{unsupported '+c' in the 'target_clones' attribute string; 'target_clones' attribute ignored}}
+void __attribute__((target_clones("default", "+c"))) invaildVersion() {}
+
+// expected-warning at +1 {{unsupported 'arch=rv64g' in the 'target_clones' attribute string; 'target_clones' attribute ignored}}
+void __attribute__((target_clones("default", "arch=rv64g"))) fullArchString() {}
+
+
+void lambda() {
+  // expected-error at +1 {{attribute 'target_clones' multiversioned functions do not yet support lambdas}}
+  auto x = []() __attribute__((target_clones("default"))){};
+  x();
+  // expected-error at +1 {{attribute 'target_clones' multiversioned functions do not yet support lambdas}}
+  auto y = []() __attribute__((target_clones("arch=+v", "default"))){};
+  y();
+}
diff --git a/llvm/include/llvm/TargetParser/RISCVTargetParser.h b/llvm/include/llvm/TargetParser/RISCVTargetParser.h
index e998bc4ca59ee..59f4bc6c80f97 100644
--- a/llvm/include/llvm/TargetParser/RISCVTargetParser.h
+++ b/llvm/include/llvm/TargetParser/RISCVTargetParser.h
@@ -32,6 +32,8 @@ struct RISCVExtensionBitmask {
 };
 } // namespace RISCVExtensionBitmaskTable
 
+static constexpr unsigned RISCVFeatureBitSize = 1;
+
 // We use 64 bits as the known part in the scalable vector types.
 static constexpr unsigned RVVBitsPerBlock = 64;
 
@@ -44,6 +46,8 @@ StringRef getMArchFromMcpu(StringRef CPU);
 void fillValidCPUArchList(SmallVectorImpl<StringRef> &Values, bool IsRV64);
 void fillValidTuneCPUArchList(SmallVectorImpl<StringRef> &Values, bool IsRV64);
 bool hasFastUnalignedAccess(StringRef CPU);
+llvm::SmallVector<unsigned long long>
+    getRequireFeatureBitMask(ArrayRef<StringRef>);
 
 } // namespace RISCV
 
diff --git a/llvm/lib/TargetParser/RISCVTargetParser.cpp b/llvm/lib/TargetParser/RISCVTargetParser.cpp
index adb594777be80..2f9fef594e894 100644
--- a/llvm/lib/TargetParser/RISCVTargetParser.cpp
+++ b/llvm/lib/TargetParser/RISCVTargetParser.cpp
@@ -140,7 +140,7 @@ struct LessExtName {
 };
 } // namespace
 
-static RISCVExtensionBitmaskTable::RISCVExtensionBitmask
+static Expected<RISCVExtensionBitmaskTable::RISCVExtensionBitmask>
 getExtensionBitmask(StringRef ExtName) {
   ArrayRef<RISCVExtensionBitmaskTable::RISCVExtensionBitmask> ExtBitmasks =
       RISCVExtensionBitmaskTable::ExtensionBitmask;
@@ -149,7 +149,21 @@ getExtensionBitmask(StringRef ExtName) {
   if (I != ExtBitmasks.end())
     return *I;
 
-  return RISCVExtensionBitmaskTable::RISCVExtensionBitmask();
+  return createStringError("Unsupport extension");
+}
+
+llvm::SmallVector<unsigned long long>
+getRequireFeatureBitMask(ArrayRef<StringRef> Exts) {
+  llvm::SmallVector<unsigned long long> BitMasks(RISCV::RISCVFeatureBitSize);
+
+  for (auto Ext : Exts) {
+    Expected<RISCVExtensionBitmaskTable::RISCVExtensionBitmask> ExtBitmask =
+        getExtensionBitmask(Ext);
+    assert(ExtBitmask && "This extension doesn't has bitmask.");
+    BitMasks[ExtBitmask->GroupID] |= (1ULL << ExtBitmask->BitPosition);
+  }
+
+  return BitMasks;
 }
 } // namespace RISCV
 

>From 10f8f50f67a381153f8a1b49834cfcf93a94dcd1 Mon Sep 17 00:00:00 2001
From: Piyou Chen <piyou.chen at sifive.com>
Date: Fri, 12 Jul 2024 02:17:34 -0700
Subject: [PATCH 4/4] Fixup format

---
 clang/lib/CodeGen/CodeGenFunction.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 27305e0f4b7b4..f2b2915878a90 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -2906,9 +2906,9 @@ void CodeGenFunction::EmitRISCVMultiVersionResolver(
       unsigned MaxGroupIDUsed = 0;
       llvm::SmallVector<StringRef, 8> CurrTargetAttrFeats;
 
-      for (auto Feat: TargetAttrFeats)
+      for (auto Feat : TargetAttrFeats)
         CurrTargetAttrFeats.push_back(StringRef(Feat).substr(1));
-      
+
       llvm::Value *SecondCondition =
           EmitRISCVCpuSupports(CurrTargetAttrFeats, MaxGroupIDUsed);
 



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