AArch64: Support runtime call simulation.

Change-Id: I063c2223a63791e90d8aa9cffc6e88f96d57187e

2 files changed, 121 insertions, 0 deletions

diff --git a/examples/aarch64/examples.h b/examples/aarch64/examples.h
index bc494bdf..adc5d4c8 100644
--- a/examples/aarch64/examples.h
+++ b/examples/aarch64/examples.h
@@ -118,5 +118,7 @@ void GenerateDemoFunction(MacroAssembler* masm);
 // `b` inputs.
 int64_t LiteralExample(int64_t a, int64_t b);
 
+// Generate a few examples of runtime calls.
+void GenerateRuntimeCallExamples(MacroAssembler* masm);
 
 #endif /* !VIXL_EXAMPLE_EXAMPLES_H_ */
diff --git a/examples/aarch64/simulated-runtime-calls.cc b/examples/aarch64/simulated-runtime-calls.cc
new file mode 100644
index 00000000..d6a6f367
--- /dev/null
+++ b/examples/aarch64/simulated-runtime-calls.cc
@@ -0,0 +1,119 @@
+// Copyright 2016, VIXL authors
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of ARM Limited nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "examples.h"
+
+#include "aarch64/disasm-aarch64.h"
+#include "aarch64/macro-assembler-aarch64.h"
+#include "aarch64/simulator-aarch64.h"
+
+#ifdef VIXL_SIMULATED_RUNTIME_CALL_SUPPORT
+
+#define __ masm->
+
+int32_t add_int32s(int32_t a, int32_t b) {
+  printf("add_int32s(%d, %d)\n", a, b);
+  return a + b;
+}
+
+float int32_to_float(int32_t value) {
+  printf("int32_to_float(%d)\n", value);
+  return static_cast<float>(value);
+}
+
+int32_t float_to_int32(float value) {
+  printf("float_to_int32(%f)\n", value);
+  return static_cast<int32_t>(value);
+}
+
+void overload_function(float value) {
+  printf("overload_function(float %f)\n", value);
+}
+
+void overload_function(int32_t value) {
+  printf("overload_function(int32_t %d)\n", value);
+}
+
+void GenerateRuntimeCallExamples(MacroAssembler* masm) {
+  // The arguments are expected in the appropriate registers (following the
+  // Aarch64 ABI).
+  __ CallRuntime(add_int32s);
+  // The result is in `w0`, as per the ABI.
+  // Of course, one can use assembly to work with the results.
+  __ Lsl(w0, w0, 2);
+  __ CallRuntime(int32_to_float);
+  // The result is in `s0`.
+  // `CallRuntime` can infer template arguments when the call is not ambiguous.
+  // Otherwise the template arguments must be specified in the form:
+  // `__ CallRuntime<return_type, parameter_type_0, parameter_type_1, ...>();`
+  __ CallRuntime<void, float>(overload_function);
+  __ CallRuntime(float_to_int32);
+  __ CallRuntime<void, int32_t>(overload_function);
+  __ Ret();
+}
+
+
+#ifndef TEST_EXAMPLES
+#ifdef VIXL_INCLUDE_SIMULATOR
+
+int main(void) {
+  MacroAssembler masm;
+
+  // Generate the code for the example function.
+  Label call_runtime_add_floats;
+  masm.Bind(&call_runtime_add_floats);
+  GenerateRuntimeCallExamples(&masm);
+  masm.FinalizeCode();
+
+  Instruction* start =
+      masm.GetLabelAddress<Instruction*>(&call_runtime_add_floats);
+
+  // Disassemble the generated code.
+  PrintDisassembler disassembler(stdout);
+  disassembler.DisassembleBuffer(start, masm.GetSizeOfCodeGenerated());
+
+  Decoder decoder;
+  Simulator simulator(&decoder);
+
+  int32_t input_a = 1;
+  int32_t input_b = 2;
+  simulator.WriteWRegister(0, input_a);
+  simulator.WriteWRegister(1, input_b);
+  simulator.RunFrom(start);
+  printf("The final result is %d\n", simulator.ReadWRegister(0));
+
+  return 0;
+}
+#else
+// TODO: Support running natively.
+int main(void) { return 0; }
+#endif  // VIXL_INCLUDE_SIMULATOR
+#endif  // TEST_EXAMPLES
+#else
+#ifndef TEST_EXAMPLES
+int main(void) { return 0; }
+#endif  // TEST_EXAMPLES
+#endif  // VIXL_SIMULATED_RUNTIME_CALL_SUPPORT