AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

[wasm][arm64] Implement AtomicCompareExchange in Liftoff

Browse Source 
R=v8-arm-ports@googlegroups.com, clemensb@chromium.org

Bug: v8:10108
Change-Id: I22dce431b8aadf25072288ecd38daa2cde029919
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2231351
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68202}
This commit is contained in:
Andreas Haas 2020-06-05 13:33:53 +02:00 committed by Commit Bot
parent a582b84a28
commit 890c113f52
1 changed files with 55 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
src/wasm/baseline/arm64/liftoff-assembler-arm64.h
View File

@ -522,7 +522,61 @@ void LiftoffAssembler::AtomicCompareExchange(
Register dst_addr, Register offset_reg, uint32_t offset_imm,
LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
StoreType type) {
bailout(kAtomics, "AtomicCompareExchange");
LiftoffRegList pinned =
LiftoffRegList::ForRegs(dst_addr, offset_reg, expected, new_value);
Register result_reg = result.gp();
if (pinned.has(result)) {
result_reg = GetUnusedRegister(kGpReg, pinned).gp();
}
UseScratchRegisterScope temps(this);
Register store_result = temps.AcquireW();
Register actual_addr = liftoff::CalculateActualAddress(
this, dst_addr, offset_reg, offset_imm, temps.AcquireX());
Label retry;
Label done;
Bind(&retry);
switch (type.value()) {
case StoreType::kI64Store8:
case StoreType::kI32Store8:
ldaxrb(result_reg.W(), actual_addr);
Cmp(result.gp().W(), Operand(expected.gp().W(), UXTB));
B(ne, &done);
stlxrb(store_result.W(), new_value.gp().W(), actual_addr);
break;
case StoreType::kI64Store16:
case StoreType::kI32Store16:
ldaxrh(result_reg.W(), actual_addr);
Cmp(result.gp().W(), Operand(expected.gp().W(), UXTH));
B(ne, &done);
stlxrh(store_result.W(), new_value.gp().W(), actual_addr);
break;
case StoreType::kI64Store32:
case StoreType::kI32Store:
ldaxr(result_reg.W(), actual_addr);
Cmp(result.gp().W(), Operand(expected.gp().W(), UXTW));
B(ne, &done);
stlxr(store_result.W(), new_value.gp().W(), actual_addr);
break;
case StoreType::kI64Store:
ldaxr(result_reg.X(), actual_addr);
Cmp(result.gp().X(), Operand(expected.gp().X(), UXTX));
B(ne, &done);
stlxr(store_result.W(), new_value.gp().X(), actual_addr);
break;
default:
UNREACHABLE();
}
Cbnz(store_result.W(), &retry);
Bind(&done);
if (result_reg != result.gp()) {
mov(result.gp(), result_reg);
}
}
void LiftoffAssembler::AtomicFence() { Dmb(InnerShareable, BarrierAll); }