• Ng Zhi An's avatar
    [wasm-simd][arm64][arm] Fix v128.const · 7c10560d
    Ng Zhi An authored
    There is a sign-extension bug happening when packing 2 32-bit ints into
    a 64-bit int. We are OR-ing int32_t with a uint64_t, so an integral
    conversion converts int32_t to uint64_t, which is a sign extension, and
    this gives unexpected results for a negative value:
    
        0x80000000 | uint64_t{0} -> 0xffffffff80000000
    
    What we want is 0x0000000080000000.
    
    Created a helper function to do this work of combining two uint32_t
    into one uint64_t. The use of this function will also ensure that
    if callers passed a int32_t, it would first be converted to a
    uint32_t, and will not have this sign extension bug.
    
    Sneaked a small regression test into the existing v128.const cctest,
    and also cleanup the loop to reset `expected` array to 0.
    
    Bug: chromium:1104033
    Change-Id: Icaca4c5ba42077dd4463697b9220cdbca9974b5e
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2293044
    Commit-Queue: Zhi An Ng <zhin@chromium.org>
    Reviewed-by: 's avatarClemens Backes <clemensb@chromium.org>
    Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#68850}
    7c10560d
code-generator-ia32.cc 183 KB