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PPC/s390: [wasm] Implement patching of far jump table

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Port 0a8ddb134c

Original Commit Message:

    If the jump is too large for a near jump, we patch the far jump table
    instead, and patch the (near) jump table to jump to the far jump table
    slot.

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

Change-Id: Ic42dfea83799ba6aae1d6d32607391393353815a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1802742
Reviewed-by: Milad Farazmand <miladfar@ca.ibm.com>
Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#63769}
This commit is contained in:
Milad Farazmand 2019-09-13 10:51:38 -04:00 committed by Commit Bot
parent fad60ef290
commit 1603f672ff
1 changed files with 14 additions and 2 deletions
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16
src/wasm/jump-table-assembler.cc
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@ -198,15 +198,21 @@ void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
b(r1); // 2 bytes
}
void JumpTableAssembler::EmitJumpSlot(Address target) {
bool JumpTableAssembler::EmitJumpSlot(Address target) {
mov(r1, Operand(target));
b(r1);
return true;
}
void JumpTableAssembler::EmitFarJumpSlot(Address target) {
JumpToInstructionStream(target);
}
// static
void JumpTableAssembler::PatchFarJumpSlot(Address slot, Address target) {
UNREACHABLE();
}
void JumpTableAssembler::NopBytes(int bytes) {
DCHECK_LE(0, bytes);
DCHECK_EQ(0, bytes % 2);
@ -259,16 +265,22 @@ void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
for (int i = 0; i < nop_bytes; i += kInstrSize) nop();
}
void JumpTableAssembler::EmitJumpSlot(Address target) {
bool JumpTableAssembler::EmitJumpSlot(Address target) {
mov(r0, Operand(target));
mtctr(r0);
bctr();
return true;
}
void JumpTableAssembler::EmitFarJumpSlot(Address target) {
JumpToInstructionStream(target);
}
// static
void JumpTableAssembler::PatchFarJumpSlot(Address slot, Address target) {
UNREACHABLE();
}
void JumpTableAssembler::NopBytes(int bytes) {
DCHECK_LE(0, bytes);
DCHECK_EQ(0, bytes % 4);