• Ng Zhi An's avatar
    Reland "[wasm-simd][liftoff] Add S128 case for stack movements" · 06594a8d
    Ng Zhi An authored
    This relands commit 5cfe053e.
    
    Original change's description:
    > [wasm-simd][liftoff] Add S128 case for stack movements
    >
    > The two cases we are fixing here are Construct and
    > LoadCallerFrameSlot, which are closely related.
    >
    > Construct is called during PrepareCall, where we build up
    > LiftoffStackSlots when we need to move an arg from caller's stack frame
    > into callee's stack frame. LoadCallerFrameSlot is the parallel to
    > this, called in ProcessParameter during decoding of the callee's
    > function body.
    >
    > In most cases, Construct needs a new case to handle kWasmS128, and calls
    > the relevant assembler to push a s128 onto the stack.
    >
    > ARM64 requires 16-byte alignment of sp, so we need to Claim the right
    > number of kXRegSize slots first, which requires
    > us traversing the list of slots to figure out how many s128 values there
    > are. This is a straightforward way to fix this, if efficiency is a
    > problem, we can change LiftOffStackSlots::Add to sum up the slot sizes.
    >
    > On IA32, pushing s128 values will require 4 calls to push. Instead, we
    > use a sub and two movdqu, which will generate less code in most cases.
    >
    > On x64, there is no 128-bit push, so we call push twice.
    >
    > Bug: v8:9909
    > Change-Id: I3af35b8462ea9c3b9b2d90800c37d11b5e95be59
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2015945
    > Commit-Queue: Zhi An Ng <zhin@chromium.org>
    > Reviewed-by: Clemens Backes <clemensb@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#65956}
    
    Bug: v8:9909
    Change-Id: Icdaead289abe13faf75bb9e049929f7fd7c59a08
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2036760
    Commit-Queue: Zhi An Ng <zhin@chromium.org>
    Reviewed-by: 's avatarClemens Backes <clemensb@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#66119}
    06594a8d
liftoff-simd-params.js 3.29 KB