From a4f47a99aafe57db0176ef7dad1a9ba72854439f Mon Sep 17 00:00:00 2001
From: joker881 <changhu779@gmail.com>
Date: Wed, 13 Apr 2022 20:38:36 +0800
Subject: [PATCH] RISCV] Add clang builtins for CLZ instruction.

add intrinsic for CLZ

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D121915
---
 clang/include/clang/Basic/BuiltinsRISCV.def        |  2 ++
 clang/lib/CodeGen/CGBuiltin.cpp                    |  7 +++++++
 .../CodeGen/RISCV/rvb-intrinsics/riscv32-zbb.c     | 12 +++++++++++
 .../CodeGen/RISCV/rvb-intrinsics/riscv64-zbb.c     | 24 ++++++++++++++++++++++
 4 files changed, 45 insertions(+)

diff --git a/clang/include/clang/Basic/BuiltinsRISCV.def b/clang/include/clang/Basic/BuiltinsRISCV.def
index 73ec6ea..74b8c9e 100644
--- a/clang/include/clang/Basic/BuiltinsRISCV.def
+++ b/clang/include/clang/Basic/BuiltinsRISCV.def
@@ -18,6 +18,8 @@
 // Zbb extension
 TARGET_BUILTIN(__builtin_riscv_orc_b_32, "ZiZi", "nc", "zbb")
 TARGET_BUILTIN(__builtin_riscv_orc_b_64, "WiWi", "nc", "zbb,64bit")
+TARGET_BUILTIN(__builtin_riscv_clz_32, "ZiZi", "nc", "zbb")
+TARGET_BUILTIN(__builtin_riscv_clz_64, "WiWi", "nc", "zbb,64bit")
 
 // Zbc or Zbkc extension
 TARGET_BUILTIN(__builtin_riscv_clmul, "LiLiLi", "nc", "zbc|zbkc")
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 4ad4acc..3adabcb 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -18992,6 +18992,8 @@ Value *CodeGenFunction::EmitRISCVBuiltinExpr(unsigned BuiltinID,
   default: llvm_unreachable("unexpected builtin ID");
   case RISCV::BI__builtin_riscv_orc_b_32:
   case RISCV::BI__builtin_riscv_orc_b_64:
+  case RISCV::BI__builtin_riscv_clz_32:
+  case RISCV::BI__builtin_riscv_clz_64:
   case RISCV::BI__builtin_riscv_clmul:
   case RISCV::BI__builtin_riscv_clmulh:
   case RISCV::BI__builtin_riscv_clmulr:
@@ -19037,6 +19039,11 @@ Value *CodeGenFunction::EmitRISCVBuiltinExpr(unsigned BuiltinID,
     case RISCV::BI__builtin_riscv_orc_b_64:
       ID = Intrinsic::riscv_orc_b;
       break;
+    case RISCV::BI__builtin_riscv_clz_32:
+    case RISCV::BI__builtin_riscv_clz_64: {
+      Function *F = CGM.getIntrinsic(Intrinsic::ctlz, Ops[0]->getType());
+      return Builder.CreateCall(F, {Ops[0], Builder.getInt1(false)});
+    }
 
     // Zbc
     case RISCV::BI__builtin_riscv_clmul:
diff --git a/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb.c b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb.c
index 1eb0250..c1827b1 100644
--- a/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb.c
+++ b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb.c
@@ -13,3 +13,15 @@
 int orc_b_32(int a) {
   return __builtin_riscv_orc_b_32(a);
 }
+
+// RV32ZBB-LABEL: @clz_32(
+// RV32ZBB-NEXT:  entry:
+// RV32ZBB-NEXT:    [[A_ADDR:%.*]] = alloca i32, align 4
+// RV32ZBB-NEXT:    store i32 [[A:%.*]], i32* [[A_ADDR]], align 4
+// RV32ZBB-NEXT:    [[TMP0:%.*]] = load i32, i32* [[A_ADDR]], align 4
+// RV32ZBB-NEXT:    [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false)
+// RV32ZBB-NEXT:    ret i32 [[TMP1]]
+//
+int clz_32(int a) {
+  return __builtin_riscv_clz_32(a);
+}
\ No newline at end of file
diff --git a/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv64-zbb.c b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv64-zbb.c
index 0130967..da2930c 100644
--- a/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv64-zbb.c
+++ b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv64-zbb.c
@@ -25,3 +25,27 @@ int orc_b_32(int a) {
 long orc_b_64(long a) {
   return __builtin_riscv_orc_b_64(a);
 }
+
+// RV64ZBB-LABEL: @clz_32(
+// RV64ZBB-NEXT:  entry:
+// RV64ZBB-NEXT:    [[A_ADDR:%.*]] = alloca i32, align 4
+// RV64ZBB-NEXT:    store i32 [[A:%.*]], i32* [[A_ADDR]], align 4
+// RV64ZBB-NEXT:    [[TMP0:%.*]] = load i32, i32* [[A_ADDR]], align 4
+// RV64ZBB-NEXT:    [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false)
+// RV64ZBB-NEXT:    ret i32 [[TMP1]]
+//
+int clz_32(int a) {
+  return __builtin_riscv_clz_32(a);
+}
+
+// RV64ZBB-LABEL: @clz_64(
+// RV64ZBB-NEXT:  entry:
+// RV64ZBB-NEXT:    [[A_ADDR:%.*]] = alloca i64, align 8
+// RV64ZBB-NEXT:    store i64 [[A:%.*]], i64* [[A_ADDR]], align 8
+// RV64ZBB-NEXT:    [[TMP0:%.*]] = load i64, i64* [[A_ADDR]], align 8
+// RV64ZBB-NEXT:    [[TMP1:%.*]] = call i64 @llvm.ctlz.i64(i64 [[TMP0]], i1 false)
+// RV64ZBB-NEXT:    ret i64 [[TMP1]]
+//
+long clz_64(long a) {
+  return __builtin_riscv_clz_64(a);
+}
\ No newline at end of file
-- 
2.7.4