[WebAssembly] Add some comments and make some minor source cleanups.

[oota-llvm.git] / lib / Target / WebAssembly / InstPrinter / WebAssemblyInstPrinter.cpp

diff --git a/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp b/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
index cbd2f7dc748a717dc7f02357352110f15db11587..7ce3a00ae360efb6e3d7007901685f25524f8f6a 100644 (file)
--- a/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
+++ b/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
@@ -13,7 +13,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "InstPrinter/WebAssemblyInstPrinter.h"
+#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
 #include "WebAssembly.h"
+#include "WebAssemblyMachineFunctionInfo.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCInstrInfo.h"
@@ -21,7 +23,7 @@
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormattedStream.h"
-#include <cctype>
+#include "llvm/Target/TargetRegisterInfo.h"
 using namespace llvm;
 
 #define DEBUG_TYPE "asm-printer"
@@ -35,25 +37,93 @@ WebAssemblyInstPrinter::WebAssemblyInstPrinter(const MCAsmInfo &MAI,
 
 void WebAssemblyInstPrinter::printRegName(raw_ostream &OS,
                                           unsigned RegNo) const {
-  OS << getRegisterName(RegNo);
+  assert(RegNo != WebAssemblyFunctionInfo::UnusedReg);
+  // Note that there's an implicit get_local/set_local here!
+  OS << "$" << RegNo;
 }
 
 void WebAssemblyInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
                                        StringRef Annot,
-                                       const MCSubtargetInfo &STI) {
+                                       const MCSubtargetInfo & /*STI*/) {
+  // Print the instruction (this uses the AsmStrings from the .td files).
   printInstruction(MI, OS);
+
+  // Print any additional variadic operands.
+  const MCInstrDesc &Desc = MII.get(MI->getOpcode());
+  if (Desc.isVariadic())
+    for (auto i = Desc.getNumOperands(), e = MI->getNumOperands(); i < e; ++i) {
+      if (i != 0)
+        OS << ", ";
+      printOperand(MI, i, OS);
+    }
+
+  // Print any added annotation.
   printAnnotation(OS, Annot);
 }
 
+static std::string toString(const APFloat &FP) {
+  static const size_t BufBytes = 128;
+  char buf[BufBytes];
+  if (FP.isNaN())
+    assert((FP.bitwiseIsEqual(APFloat::getQNaN(FP.getSemantics())) ||
+            FP.bitwiseIsEqual(
+                APFloat::getQNaN(FP.getSemantics(), /*Negative=*/true))) &&
+           "convertToHexString handles neither SNaN nor NaN payloads");
+  // Use C99's hexadecimal floating-point representation.
+  auto Written = FP.convertToHexString(
+      buf, /*hexDigits=*/0, /*upperCase=*/false, APFloat::rmNearestTiesToEven);
+  (void)Written;
+  assert(Written != 0);
+  assert(Written < BufBytes);
+  return buf;
+}
+
 void WebAssemblyInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
                                           raw_ostream &O) {
   const MCOperand &Op = MI->getOperand(OpNo);
-  if (Op.isReg())
-    O << getRegisterName(Op.getReg());
-  else if (Op.isImm())
-    O << '#' << Op.getImm();
+  if (Op.isReg()) {
+    unsigned WAReg = Op.getReg();
+    if (int(WAReg) >= 0)
+      printRegName(O, WAReg);
+    else if (OpNo >= MII.get(MI->getOpcode()).getNumDefs())
+      O << "$pop" << (WAReg & INT32_MAX);
+    else if (WAReg != WebAssemblyFunctionInfo::UnusedReg)
+      O << "$push" << (WAReg & INT32_MAX);
+    else
+      O << "$discard";
+    // Add a '=' suffix if this is a def.
+    if (OpNo < MII.get(MI->getOpcode()).getNumDefs())
+      O << '=';
+  } else if (Op.isImm()) {
+    switch (MI->getOpcode()) {
+    case WebAssembly::PARAM:
+    case WebAssembly::RESULT:
+    case WebAssembly::LOCAL:
+      O << WebAssembly::TypeToString(MVT::SimpleValueType(Op.getImm()));
+      break;
+    default:
+      O << Op.getImm();
+      break;
+    }
+  } else if (Op.isFPImm())
+    O << toString(APFloat(Op.getFPImm()));
   else {
     assert(Op.isExpr() && "unknown operand kind in printOperand");
     Op.getExpr()->print(O, &MAI);
   }
 }
+
+const char *llvm::WebAssembly::TypeToString(MVT Ty) {
+  switch (Ty.SimpleTy) {
+  case MVT::i32:
+    return "i32";
+  case MVT::i64:
+    return "i64";
+  case MVT::f32:
+    return "f32";
+  case MVT::f64:
+    return "f64";
+  default:
+    llvm_unreachable("unsupported type");
+  }
+}