[llvm][clang] Add intrinsic support for cbo.zero instruction (Zicboz ISA extension)

Author: t-baydyusenov

clang/include/clang/Basic/BuiltinsRISCV.td

@@ -153,6 +153,13 @@ def ntl_store : RISCVBuiltin<"void(...)">;
 let Features = "zihintpause", Attributes = [NoThrow] in
 def pause : RISCVBuiltin<"void()">;
 
+//===----------------------------------------------------------------------===//
+// Zicboz extension.
+//===----------------------------------------------------------------------===//
+let Features = "zicboz" in {
+def cbo_zero : RISCVBuiltin<"void(void *)">;
+} // Features = "zicboz"
+
 //===----------------------------------------------------------------------===//
 // XCV extensions.
 //===----------------------------------------------------------------------===//

clang/lib/CodeGen/TargetBuiltins/RISCV.cpp

@@ -1296,6 +1296,12 @@ Value *CodeGenFunction::EmitRISCVBuiltinExpr(unsigned BuiltinID,
     return Builder.CreateCall(Fn, {});
   }
 
+  // Zicboz
+  case RISCV::BI__builtin_riscv_cbo_zero:
+    ID = Intrinsic::riscv_cbo_zero;
+    IntrinsicTypes = {Int8PtrTy};
+    break;
+
   // XCValu
   case RISCV::BI__builtin_riscv_cv_alu_addN:
     ID = Intrinsic::riscv_cv_alu_addN;

clang/lib/Headers/CMakeLists.txt

@@ -125,6 +125,7 @@ set(ppc_htm_files
 
 set(riscv_files
   riscv_bitmanip.h
+  riscv_cmo.h
   riscv_corev_alu.h
   riscv_crypto.h
   riscv_nds.h

clang/lib/Headers/riscv_cmo.h

@@ -0,0 +1,28 @@
+/*===---- riscv_cmo.h - RISC-V CMO intrinsics ----------------------------===
+ *
+ * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+ * See https://llvm.org/LICENSE.txt for license information.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef __RISCV_CMO_H
+#define __RISCV_CMO_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#if defined(__riscv_zicboz)
+static __inline__ void __attribute__((__always_inline__, __nodebug__))
+__riscv_cbo_zero(void *__x) {
+  return __builtin_riscv_cbo_zero(__x);
+}
+#endif // defined(__riscv_zicboz)
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif // define __RISCV_CMO_H

clang/test/CodeGen/RISCV/riscv-zicbo-intrinsics/cbo-zero-invalid.c

@@ -0,0 +1,12 @@
+// REQUIRES: riscv-registered-target
+// RUN: %clang_cc1 -triple riscv64 -target-feature +zicboz \
+// RUN:   -Wall -Wno-unused -Werror -fsyntax-only -verify %s
+
+#include <riscv_cmo.h>
+
+void test(void *x) {
+	__riscv_cbo_zero(x, 0); // expected-error{{too many arguments to function call, expected single argument '__x', have 2 arguments}} expected-note@riscv_cmo.h:* {{'__riscv_cbo_zero' declared here}}
+	int res = __riscv_cbo_zero(x); // expected-error{{initializing 'int' with an expression of incompatible type 'void'}}
+	__riscv_cbo_zero(42); // expected-error{{incompatible integer to pointer conversion passing 'int' to parameter of type 'void *'}} expected-note@riscv_cmo.h:* {{passing argument to parameter '__x' here}}
+}
+

clang/test/CodeGen/RISCV/riscv-zicbo-intrinsics/cbo-zero-valid.c

@@ -0,0 +1,13 @@
+
+// REQUIRES: riscv-registered-target
+// RUN: %clang_cc1 -triple riscv64 -target-feature +zicboz -O2 -S -o - %s | FileCheck %s
+
+#include <riscv_cmo.h>
+
+void test(void *x) {
+// CHECK-LABEL: test:
+// CHECK:       cbo.zero (a0)
+// CHECK:       ret
+  __riscv_cbo_zero(x);
+}
+

llvm/include/llvm/IR/IntrinsicsRISCV.td

@@ -1953,13 +1953,20 @@ let TargetPrefix = "riscv" in {
 } // TargetPrefix = "riscv"
 
 
-// Zihintpause extensions
 //===----------------------------------------------------------------------===//
+// Zihintpause extensions
 let TargetPrefix = "riscv" in
 def int_riscv_pause : DefaultAttrsIntrinsic<[], [], [IntrNoMem, IntrHasSideEffects]>;
 
-// Vendor extensions
 //===----------------------------------------------------------------------===//
+// Cache Management
+let TargetPrefix = "riscv" in {
+// Zicboz
+def int_riscv_cbo_zero : Intrinsic<[], [llvm_anyptr_ty], [IntrWriteMem]>;
+} // TargetPrefix = "riscv"
+
+//===----------------------------------------------------------------------===//
+// Vendor extensions
 include "llvm/IR/IntrinsicsRISCVXTHead.td"
 include "llvm/IR/IntrinsicsRISCVXsf.td"
 include "llvm/IR/IntrinsicsRISCVXCV.td"

llvm/lib/Target/RISCV/RISCVInstrInfoZicbo.td

@@ -56,6 +56,7 @@ def CBO_INVAL : CBO_r<0b000000000000, "cbo.inval">, Sched<[]>;
 
 let Predicates = [HasStdExtZicboz] in {
 def CBO_ZERO : CBO_r<0b000000000100, "cbo.zero">, Sched<[]>;
+def : Pat<(int_riscv_cbo_zero GPR:$rs1), (CBO_ZERO GPR:$rs1)>;
 } // Predicates = [HasStdExtZicboz]
 
 let Predicates = [HasStdExtZicbop, NoVendorXMIPSCBOP] in {