[WebAssembly] memory.copy

Summary: Depends on D57495.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, hiraditya, sunfish

Differential Revision: https://reviews.llvm.org/D57498

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353127 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/WebAssembly/WebAssemblyISD.def

@@ -25,5 +25,6 @@ HANDLE_NODETYPE(VEC_SHL)
 HANDLE_NODETYPE(VEC_SHR_S)
 HANDLE_NODETYPE(VEC_SHR_U)
 HANDLE_NODETYPE(THROW)
+HANDLE_NODETYPE(MEMORY_COPY)
 
 // add memory opcodes starting at ISD::FIRST_TARGET_MEMORY_OPCODE here...

lib/Target/WebAssembly/WebAssemblyISelLowering.cpp

@@ -243,6 +243,12 @@ WebAssemblyTargetLowering::WebAssemblyTargetLowering(
   setOperationAction(ISD::INTRINSIC_VOID, MVT::Other, Custom);
 
   setMaxAtomicSizeInBitsSupported(64);
+
+  if (Subtarget->hasBulkMemory()) {
+    // Using memory.copy is always better than using multiple loads and stores
+    MaxStoresPerMemcpy = 1;
+    MaxStoresPerMemcpyOptSize = 1;
+  }
 }
 
 TargetLowering::AtomicExpansionKind

lib/Target/WebAssembly/WebAssemblyInstrBulkMemory.td

@@ -0,0 +1,39 @@
+// WebAssemblyInstrBulkMemory.td - bulk memory codegen support --*- tablegen -*-
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// WebAssembly bulk memory codegen constructs.
+///
+//===----------------------------------------------------------------------===//
+
+// Instruction requiring HasBulkMemory and the bulk memory prefix byte
+multiclass BULK_I<dag oops_r, dag iops_r, dag oops_s, dag iops_s,
+                  list<dag> pattern_r, string asmstr_r = "",
+                  string asmstr_s = "", bits<32> simdop = -1> {
+  defm "" : I<oops_r, iops_r, oops_s, iops_s, pattern_r, asmstr_r, asmstr_s,
+              !or(0xfc00, !and(0xff, simdop))>,
+            Requires<[HasBulkMemory]>;
+}
+
+// Bespoke types and nodes for bulk memory ops
+def wasm_memcpy_t : SDTypeProfile<0, 3,
+  [SDTCisPtrTy<0>, SDTCisPtrTy<1>, SDTCisInt<2>]
+>;
+def wasm_memcpy : SDNode<"WebAssemblyISD::MEMORY_COPY", wasm_memcpy_t,
+                         [SDNPHasChain, SDNPMayLoad, SDNPMayStore]>;
+
+//===----------------------------------------------------------------------===//
+// memory.copy
+//===----------------------------------------------------------------------===//
+
+let mayLoad = 1, mayStore = 1 in
+defm MEMORY_COPY : BULK_I<(outs), (ins I32:$dst, I32:$src, I32:$len),
+                          (outs), (ins),
+                          [(wasm_memcpy I32:$dst, I32:$src, I32:$len)],
+                          "memory.copy\t$dst, $src, $len",
+                          "memory.copy", 0x0a>;

lib/Target/WebAssembly/WebAssemblyInstrInfo.td

@@ -315,3 +315,4 @@ include "WebAssemblyInstrFloat.td"
 include "WebAssemblyInstrAtomics.td"
 include "WebAssemblyInstrSIMD.td"
 include "WebAssemblyInstrExceptRef.td"
+include "WebAssemblyInstrBulkMemory.td"

lib/Target/WebAssembly/WebAssemblySelectionDAGInfo.cpp

@@ -17,3 +17,16 @@ using namespace llvm;
 #define DEBUG_TYPE "wasm-selectiondag-info"
 
 WebAssemblySelectionDAGInfo::~WebAssemblySelectionDAGInfo() = default; // anchor
+
+SDValue WebAssemblySelectionDAGInfo::EmitTargetCodeForMemcpy(
+    SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Op1, SDValue Op2,
+    SDValue Op3, unsigned Align, bool isVolatile, bool AlwaysInline,
+    MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
+  if (!DAG.getMachineFunction()
+           .getSubtarget<WebAssemblySubtarget>()
+           .hasBulkMemory())
+    return SDValue();
+
+  return DAG.getNode(WebAssemblyISD::MEMORY_COPY, DL, MVT::Other, Chain, Op1,
+                     Op2, Op3);
+}

lib/Target/WebAssembly/WebAssemblySelectionDAGInfo.h

@@ -22,6 +22,12 @@ namespace llvm {
 class WebAssemblySelectionDAGInfo final : public SelectionDAGTargetInfo {
 public:
   ~WebAssemblySelectionDAGInfo() override;
+  SDValue EmitTargetCodeForMemcpy(SelectionDAG &DAG, const SDLoc &dl,
+                                  SDValue Chain, SDValue Op1, SDValue Op2,
+                                  SDValue Op3, unsigned Align, bool isVolatile,
+                                  bool AlwaysInline,
+                                  MachinePointerInfo DstPtrInfo,
+                                  MachinePointerInfo SrcPtrInfo) const override;
 };
 
 } // end namespace llvm