xref: /llvm-project/llvm/lib/Target/WebAssembly/WebAssemblySelectionDAGInfo.cpp (revision 9ae92d70561bcc95a7f818920238e764253d9758)
1 //===-- WebAssemblySelectionDAGInfo.cpp - WebAssembly SelectionDAG Info ---===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file implements the WebAssemblySelectionDAGInfo class.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "WebAssemblyTargetMachine.h"
15 using namespace llvm;
16 
17 #define DEBUG_TYPE "wasm-selectiondag-info"
18 
19 WebAssemblySelectionDAGInfo::~WebAssemblySelectionDAGInfo() = default; // anchor
20 
21 bool WebAssemblySelectionDAGInfo::isTargetMemoryOpcode(unsigned Opcode) const {
22   switch (static_cast<WebAssemblyISD::NodeType>(Opcode)) {
23   default:
24     return false;
25   case WebAssemblyISD::GLOBAL_GET:
26   case WebAssemblyISD::GLOBAL_SET:
27   case WebAssemblyISD::TABLE_GET:
28   case WebAssemblyISD::TABLE_SET:
29     return true;
30   }
31 }
32 
33 SDValue WebAssemblySelectionDAGInfo::EmitTargetCodeForMemcpy(
34     SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Dst, SDValue Src,
35     SDValue Size, Align Alignment, bool IsVolatile, bool AlwaysInline,
36     MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
37   auto &ST = DAG.getMachineFunction().getSubtarget<WebAssemblySubtarget>();
38   if (!ST.hasBulkMemoryOpt())
39     return SDValue();
40 
41   SDValue MemIdx = DAG.getConstant(0, DL, MVT::i32);
42   auto LenMVT = ST.hasAddr64() ? MVT::i64 : MVT::i32;
43 
44   // Use `MEMCPY` here instead of `MEMORY_COPY` because `memory.copy` traps
45   // if the pointers are invalid even if the length is zero. `MEMCPY` gets
46   // extra code to handle this in the way that LLVM IR expects.
47   return DAG.getNode(
48       WebAssemblyISD::MEMCPY, DL, MVT::Other,
49       {Chain, MemIdx, MemIdx, Dst, Src, DAG.getZExtOrTrunc(Size, DL, LenMVT)});
50 }
51 
52 SDValue WebAssemblySelectionDAGInfo::EmitTargetCodeForMemmove(
53     SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Op1, SDValue Op2,
54     SDValue Op3, Align Alignment, bool IsVolatile,
55     MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
56   return EmitTargetCodeForMemcpy(DAG, DL, Chain, Op1, Op2, Op3,
57                                  Alignment, IsVolatile, false,
58                                  DstPtrInfo, SrcPtrInfo);
59 }
60 
61 SDValue WebAssemblySelectionDAGInfo::EmitTargetCodeForMemset(
62     SelectionDAG &DAG, const SDLoc &DL, SDValue Chain, SDValue Dst, SDValue Val,
63     SDValue Size, Align Alignment, bool IsVolatile, bool AlwaysInline,
64     MachinePointerInfo DstPtrInfo) const {
65   auto &ST = DAG.getMachineFunction().getSubtarget<WebAssemblySubtarget>();
66   if (!ST.hasBulkMemoryOpt())
67     return SDValue();
68 
69   SDValue MemIdx = DAG.getConstant(0, DL, MVT::i32);
70   auto LenMVT = ST.hasAddr64() ? MVT::i64 : MVT::i32;
71 
72   // Use `MEMSET` here instead of `MEMORY_FILL` because `memory.fill` traps
73   // if the pointers are invalid even if the length is zero. `MEMSET` gets
74   // extra code to handle this in the way that LLVM IR expects.
75   //
76   // Only low byte matters for val argument, so anyext the i8
77   return DAG.getNode(WebAssemblyISD::MEMSET, DL, MVT::Other, Chain, MemIdx, Dst,
78                      DAG.getAnyExtOrTrunc(Val, DL, MVT::i32),
79                      DAG.getZExtOrTrunc(Size, DL, LenMVT));
80 }
81