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PPC/s390: [wasm][arm][arm64][liftoff] Allow loads from negative indices

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Port 4765c70fa6

Original Commit Message:

    On arm, the root register points into the middle of the roots array to
    allow to use the full int12_t offset range. Therefore some offsets into
    the root array are negative. This CL changes the liftoff assembler for
    arm to allow loads from negative offsets.

    On arm64, offsets can also be negative when pointer compression is
    disabled.

    Additionally this CL changes the signature of
    LiftoffAssembler::LoadTaggedPointer from uint32_t to int32_t to allow
    the LiftoffCompiler to provide negative indices.

    This CL does not come with a separate test yet. However, this changes is
    needed for https://crrev.com/c/2352784. Where there will also be a test.

R=ahaas@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: Ie286b0169a5f7a1de90e0ec7002bfac83383ea6c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2363127
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#69456}
This commit is contained in:
Milad Farazmand 2020-08-18 13:54:46 +00:00 committed by Commit Bot
parent 066183eeb1
commit 2638328dc9
2 changed files with 2 additions and 2 deletions
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2
src/wasm/baseline/ppc/liftoff-assembler-ppc.h
View File

@ -114,7 +114,7 @@ void LiftoffAssembler::FillInstanceInto(Register dst) {
void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
Register offset_reg,
uint32_t offset_imm,
int32_t offset_imm,
LiftoffRegList pinned) {
bailout(kUnsupportedArchitecture, "LoadTaggedPointer");
}

2
src/wasm/baseline/s390/liftoff-assembler-s390.h
View File

@ -113,7 +113,7 @@ void LiftoffAssembler::FillInstanceInto(Register dst) {
void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
Register offset_reg,
uint32_t offset_imm,
int32_t offset_imm,
LiftoffRegList pinned) {
bailout(kUnsupportedArchitecture, "LoadTaggedPointer");
}