[CIR][CodeGen] Add support for x86 memory fence (llvm#1519)

Author: shrikardongre

clang/lib/CIR/CodeGen/CIRGenBuiltinX86.cpp

@@ -113,7 +113,6 @@ mlir::Value CIRGenFunction::emitX86BuiltinExpr(unsigned BuiltinID,
             voidTy)
         .getResult();
   }
-
   case X86::BI_mm_pause: {
     mlir::Type voidTy = cir::VoidType::get(&getMLIRContext());
     return builder
@@ -122,5 +121,21 @@ mlir::Value CIRGenFunction::emitX86BuiltinExpr(unsigned BuiltinID,
             voidTy)
         .getResult();
   }
+  case X86::BI_mm_mfence: {
+    mlir::Type voidTy = cir::VoidType::get(&getMLIRContext());
+    return builder
+        .create<cir::LLVMIntrinsicCallOp>(
+            getLoc(E->getExprLoc()), builder.getStringAttr("x86.sse2.mfence"),
+            voidTy)
+        .getResult();
+  }
+  case X86::BI_mm_sfence: {
+    mlir::Type voidTy = cir::VoidType::get(&getMLIRContext());
+    return builder
+        .create<cir::LLVMIntrinsicCallOp>(
+            getLoc(E->getExprLoc()), builder.getStringAttr("x86.sse.sfence"),
+            voidTy)
+        .getResult();
+  }
   }
 }

clang/test/CIR/CodeGen/X86/builtins-x86.c

@@ -29,3 +29,21 @@ void test_mm_pause() {
   // CIR: {{%.*}} = cir.llvm.intrinsic "x86.sse2.pause" : () -> !void
   // LLVM: call void @llvm.x86.sse2.pause()
 }
+
+void test_mm_mfence() {
+  // CIR-LABEL: test_mm_mfence
+  // LLVM-LABEL: test_mm_mfence
+  _mm_mfence();
+  // CIR: {{%.*}} = cir.llvm.intrinsic "x86.sse2.mfence" : () -> !void
+  // LLVM: call void @llvm.x86.sse2.mfence()
+}
+
+void test_mm_sfence() {
+  // CIR-LABEL: test_mm_sfence
+  // LLVM-LABEL: test_mm_sfence
+  _mm_sfence();
+  // CIR: {{%.*}} = cir.llvm.intrinsic "x86.sse.sfence" : () -> !void
+  // LLVM: call void @llvm.x86.sse.sfence()
+}
+
+