Merge pull request rust-lang#156 from ptersilie/zext

Lower zext instructions.

Author: ltratt

llvm/lib/YkIR/YkIRWriter.cpp

@@ -77,6 +77,7 @@ enum TypeKind {
 
 enum CastKind {
   CastKindSignExt = 0,
+  CastKindZeroExt = 1,
 };
 
 // A predicate used in a numeric comparison.
@@ -843,7 +844,7 @@ class YkIRWriter {
 
   void serialiseCastKind(enum CastKind Cast) { OutStreamer.emitInt8(Cast); }
 
-  /// Serialise a cast-like insruction.
+  /// Serialise a cast-like instruction.
   void serialiseSExtInst(SExtInst *I, FuncLowerCtxt &FLCtxt, unsigned BBIdx,
                          unsigned &InstIdx) {
     // opcode:
@@ -859,6 +860,22 @@ class YkIRWriter {
     InstIdx++;
   }
 
+  /// Serialise a cast-like instruction.
+  void serialiseZExtInst(ZExtInst *I, FuncLowerCtxt &FLCtxt, unsigned BBIdx,
+                         unsigned &InstIdx) {
+    // opcode:
+    serialiseOpcode(OpCodeCast);
+    // cast_kind:
+    serialiseCastKind(CastKindZeroExt);
+    // val:
+    serialiseOperand(I, FLCtxt, I->getOperand(0));
+    // dest_type_idx:
+    OutStreamer.emitSizeT(typeIndex(I->getDestTy()));
+
+    FLCtxt.updateVLMap(I, InstIdx);
+    InstIdx++;
+  }
+
   void serialiseSwitchInst(SwitchInst *I, FuncLowerCtxt &FLCtxt, unsigned BBIdx,
                            unsigned &InstIdx) {
     // opcode:
@@ -925,6 +942,7 @@ class YkIRWriter {
     INST_SERIALISE(I, LoadInst, serialiseLoadInst);
     INST_SERIALISE(I, PHINode, serialisePhiInst);
     INST_SERIALISE(I, ReturnInst, serialiseReturnInst);
+    INST_SERIALISE(I, ZExtInst, serialiseZExtInst);
     INST_SERIALISE(I, SExtInst, serialiseSExtInst);
     INST_SERIALISE(I, StoreInst, serialiseStoreInst);
     INST_SERIALISE(I, SwitchInst, serialiseSwitchInst);