riscv64: rewrite `CreateTrampoline` using assembler to generate code.
Previously we did not have an assembler for RISC-V, so the instructions
were hardcoded manually. This commit does not change the generated
instructions (aside from using a different temporary register).
Also, fix a clang-tidy error triggered by this commit (add noexcept to
constructor).
Bug: 283082089
Test: boot cuttlefish, observe no crashes in zygote:
$ lunch aosp_cf_riscv64_phone-userdebug && m
$ launch_cvd --gpu_mode=drm_virgl
Test: lunch aosp_arm64-userdebug && m art-tidy
Change-Id: I512a1d408ee3837a4a7631cad6e5da6244b402d4
diff --git a/compiler/trampolines/trampoline_compiler.cc b/compiler/trampolines/trampoline_compiler.cc
index e542763..3821399 100644
--- a/compiler/trampolines/trampoline_compiler.cc
+++ b/compiler/trampolines/trampoline_compiler.cc
@@ -28,6 +28,10 @@
#include "utils/arm64/assembler_arm64.h"
#endif
+#ifdef ART_ENABLE_CODEGEN_riscv64
+#include "utils/riscv64/assembler_riscv64.h"
+#endif
+
#ifdef ART_ENABLE_CODEGEN_x86
#include "utils/x86/assembler_x86.h"
#endif
@@ -129,48 +133,33 @@
#ifdef ART_ENABLE_CODEGEN_riscv64
namespace riscv64 {
-static std::unique_ptr<const std::vector<uint8_t>> CreateTrampoline(
- ArenaAllocator* /*allocator*/, EntryPointCallingConvention abi, ThreadOffset64 offset) {
- if (abi == kJniAbi) {
- // TODO(riscv64): implement this properly once we have macro-assembler for RISC-V.
- std::unique_ptr<std::vector<uint8_t>> entry_stub(new std::vector<uint8_t>(2));
- uint8_t* bytes = entry_stub->data();
+static std::unique_ptr<const std::vector<uint8_t>> CreateTrampoline(ArenaAllocator* allocator,
+ EntryPointCallingConvention abi,
+ ThreadOffset64 offset) {
+ Riscv64Assembler assembler(allocator);
- // 0000 unimp
- bytes[0] = 0x00;
- bytes[1] = 0x00;
-
- return std::move(entry_stub);
- } else {
- CHECK_LE(offset.Int32Value(), 0x7ff);
- uint8_t offset_hi = (offset.Int32Value() & 0x7ff) >> 4;
- uint8_t offset_lo = (offset.Int32Value() & 0xf) << 4;
-
- std::unique_ptr<std::vector<uint8_t>> entry_stub(new std::vector<uint8_t>(6));
- uint8_t* bytes = entry_stub->data();
-
- if (abi == kInterpreterAbi) {
- // Thread* is first argument (A0) in interpreter ABI.
- // xxx53283 ld t0, xxx(a0)
- bytes[0] = 0x83;
- bytes[1] = 0x32;
- bytes[2] = offset_lo | 0x05;
- bytes[3] = offset_hi;
- } else {
- // abi == kQuickAbi: TR holds Thread*.
- // xxx4b283 ld t0, xxx(s1)
- bytes[0] = 0x83;
- bytes[1] = 0xb2;
- bytes[2] = offset_lo | 0x04;
- bytes[3] = offset_hi;
- }
-
- // 8282 jr t0
- bytes[4] = 0x82;
- bytes[5] = 0x82;
-
- return std::move(entry_stub);
+ switch (abi) {
+ case kInterpreterAbi: // Thread* is first argument (A0) in interpreter ABI.
+ __ Loadd(TMP, A0, offset.Int32Value());
+ __ Jr(TMP);
+ break;
+ case kJniAbi: // Load via Thread* held in JNIEnv* in first argument (A0).
+ // TODO(riscv64): implement this.
+ __ Unimp();
+ break;
+ case kQuickAbi: // TR holds Thread*.
+ __ Loadd(TMP, TR, offset.Int32Value());
+ __ Jr(TMP);
+ break;
}
+
+ __ FinalizeCode();
+ size_t cs = __ CodeSize();
+ std::unique_ptr<std::vector<uint8_t>> entry_stub(new std::vector<uint8_t>(cs));
+ MemoryRegion code(entry_stub->data(), entry_stub->size());
+ __ FinalizeInstructions(code);
+
+ return std::move(entry_stub);
}
} // namespace riscv64
#endif // ART_ENABLE_CODEGEN_riscv64
diff --git a/compiler/utils/riscv64/assembler_riscv64.h b/compiler/utils/riscv64/assembler_riscv64.h
index d94433f..9cb6519 100644
--- a/compiler/utils/riscv64/assembler_riscv64.h
+++ b/compiler/utils/riscv64/assembler_riscv64.h
@@ -66,7 +66,7 @@
public:
Riscv64Label() : prev_branch_id_(kNoPrevBranchId) {}
- Riscv64Label(Riscv64Label&& src)
+ Riscv64Label(Riscv64Label&& src) noexcept
: Label(std::move(src)), prev_branch_id_(src.prev_branch_id_) {}
private:
