i64: Handle i64 values in phi nodes

Author: Mark Seaborn

codegen.cc

@@ -509,10 +509,14 @@ void handle_phi_nodes(llvm::BasicBlock *from_bb,
     llvm::PHINode *phi = llvm::dyn_cast<llvm::PHINode>(inst);
     if (!phi)
       break;
+    llvm::Value *incoming = phi->getIncomingValueForBlock(from_bb);
     if (is_i64(phi->getType())) {
-      codebuf.unhandled_case("i64 in PHINode");
+      codebuf.move_part_to_reg(tmp_reg, incoming, 0);
+      codebuf.spill_part(tmp_reg, phi, 0);
+      codebuf.move_part_to_reg(tmp_reg, incoming, 4);
+      codebuf.spill_part(tmp_reg, phi, 4);
     } else {
-      codebuf.move_to_reg(tmp_reg, phi->getIncomingValueForBlock(from_bb));
+      codebuf.move_to_reg(tmp_reg, incoming);
       codebuf.spill(tmp_reg, phi);
     }
   }

codegen_test.cc

@@ -250,6 +250,13 @@ void test_features() {
   ASSERT_EQ(func(99), 123);
   ASSERT_EQ(func(98), 456);
 
+  {
+    uint64_t (*funcp)(uint64_t arg);
+    GET_FUNC(funcp, "test_phi_i64");
+    ASSERT_EQ(funcp(99), 123);
+    ASSERT_EQ(funcp(98), 456);
+  }
+
   GET_FUNC(func, "test_select");
   ASSERT_EQ(func(99), 123);
   ASSERT_EQ(func(98), 456);