Quelle testAssemblerBuffer.cpp Sprache: C

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <stdlib.h>

#include "jit/shared/IonAssemblerBufferWithConstantPools.h"
#include "jsapi-tests/tests.h"

// Tests for classes in:
//
//   jit/shared/IonAssemblerBuffer.h
//   jit/shared/IonAssemblerBufferWithConstantPools.h
//
// Classes in js::jit tested:
//
//   BufferOffset
//   BufferSlice (implicitly)
//   AssemblerBuffer
//
//   BranchDeadlineSet
//   Pool (implicitly)
//   AssemblerBufferWithConstantPools
//

BEGIN_TEST(testAssemblerBuffer_BufferOffset) {
  using js::jit::BufferOffset;

  BufferOffset off1;
  BufferOffset off2(10);

  CHECK(!off1.assigned());
  CHECK(off2.assigned());
  CHECK_EQUAL(off2.getOffset(), 10);
  off1 = off2;
  CHECK(off1.assigned());
  CHECK_EQUAL(off1.getOffset(), 10);

  return true;
}
END_TEST(testAssemblerBuffer_BufferOffset)

BEGIN_TEST(testAssemblerBuffer_AssemblerBuffer) {
  using js::jit::BufferOffset;
  using AsmBuf = js::jit::AssemblerBuffer<5 * sizeof(uint32_t), uint32_t>;

  AsmBuf ab;
  CHECK(ab.isAligned(16));
  CHECK_EQUAL(ab.size(), 0u);
  CHECK_EQUAL(ab.nextOffset().getOffset(), 0);
  CHECK(!ab.oom());

  BufferOffset off1 = ab.putInt(1000017);
  CHECK_EQUAL(off1.getOffset(), 0);
  CHECK_EQUAL(ab.size(), 4u);
  CHECK_EQUAL(ab.nextOffset().getOffset(), 4);
  CHECK(!ab.isAligned(16));
  CHECK(ab.isAligned(4));
  CHECK(ab.isAligned(1));
  CHECK_EQUAL(*ab.getInst(off1), 1000017u);

  BufferOffset off2 = ab.putInt(1000018);
  CHECK_EQUAL(off2.getOffset(), 4);

  BufferOffset off3 = ab.putInt(1000019);
  CHECK_EQUAL(off3.getOffset(), 8);

  BufferOffset off4 = ab.putInt(1000020);
  CHECK_EQUAL(off4.getOffset(), 12);
  CHECK_EQUAL(ab.size(), 16u);
  CHECK_EQUAL(ab.nextOffset().getOffset(), 16);

  // Last one in the slice.
  BufferOffset off5 = ab.putInt(1000021);
  CHECK_EQUAL(off5.getOffset(), 16);
  CHECK_EQUAL(ab.size(), 20u);
  CHECK_EQUAL(ab.nextOffset().getOffset(), 20);

  BufferOffset off6 = ab.putInt(1000022);
  CHECK_EQUAL(off6.getOffset(), 20);
  CHECK_EQUAL(ab.size(), 24u);
  CHECK_EQUAL(ab.nextOffset().getOffset(), 24);

  // Reference previous slice. Excercise the finger.
  CHECK_EQUAL(*ab.getInst(off1), 1000017u);
  CHECK_EQUAL(*ab.getInst(off6), 1000022u);
  CHECK_EQUAL(*ab.getInst(off1), 1000017u);
  CHECK_EQUAL(*ab.getInst(off5), 1000021u);

  // Too much data for one slice.
  const uint32_t fixdata[] = {2000036, 2000037, 2000038,
                              2000039, 2000040, 2000041};

  // Split payload across multiple slices.
  CHECK_EQUAL(ab.nextOffset().getOffset(), 24);
  BufferOffset good1 = ab.putBytesLarge(sizeof(fixdata), fixdata);
  CHECK_EQUAL(good1.getOffset(), 24);
  CHECK_EQUAL(ab.nextOffset().getOffset(), 48);
  CHECK_EQUAL(*ab.getInst(good1), 2000036u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(32)), 2000038u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(36)), 2000039u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(40)), 2000040u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(44)), 2000041u);

  return true;
}
END_TEST(testAssemblerBuffer_AssemblerBuffer)

BEGIN_TEST(testAssemblerBuffer_BranchDeadlineSet) {
  using DLSet = js::jit::BranchDeadlineSet<3>;
  using js::jit::BufferOffset;

  js::LifoAlloc alloc(1024, js::MallocArena);
  DLSet dls(alloc);

  CHECK(dls.empty());
  CHECK(alloc.isEmpty());  // Constructor must be infallible.
  CHECK_EQUAL(dls.size(), 0u);
  CHECK_EQUAL(dls.maxRangeSize(), 0u);

  // Removing non-existant deadline is OK.
  dls.removeDeadline(1, BufferOffset(7));

  // Add deadlines in increasing order as intended. This is optimal.
  dls.addDeadline(1, BufferOffset(10));
  CHECK(!dls.empty());
  CHECK_EQUAL(dls.size(), 1u);
  CHECK_EQUAL(dls.maxRangeSize(), 1u);
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
  CHECK_EQUAL(dls.earliestDeadlineRange(), 1u);

  // Removing non-existant deadline is OK.
  dls.removeDeadline(1, BufferOffset(7));
  dls.removeDeadline(1, BufferOffset(17));
  dls.removeDeadline(0, BufferOffset(10));
  CHECK_EQUAL(dls.size(), 1u);
  CHECK_EQUAL(dls.maxRangeSize(), 1u);

  // Two identical deadlines for different ranges.
  dls.addDeadline(2, BufferOffset(10));
  CHECK(!dls.empty());
  CHECK_EQUAL(dls.size(), 2u);
  CHECK_EQUAL(dls.maxRangeSize(), 1u);
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);

  // It doesn't matter which range earliestDeadlineRange() reports first,
  // but it must report both.
  if (dls.earliestDeadlineRange() == 1) {
    dls.removeDeadline(1, BufferOffset(10));
    CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
    CHECK_EQUAL(dls.earliestDeadlineRange(), 2u);
  } else {
    CHECK_EQUAL(dls.earliestDeadlineRange(), 2u);
    dls.removeDeadline(2, BufferOffset(10));
    CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
    CHECK_EQUAL(dls.earliestDeadlineRange(), 1u);
  }

  // Add deadline which is the front of range 0, but not the global earliest.
  dls.addDeadline(0, BufferOffset(20));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
  CHECK(dls.earliestDeadlineRange() > 0);

  // Non-optimal add to front of single-entry range 0.
  dls.addDeadline(0, BufferOffset(15));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
  CHECK(dls.earliestDeadlineRange() > 0);

  // Append to 2-entry range 0.
  dls.addDeadline(0, BufferOffset(30));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
  CHECK(dls.earliestDeadlineRange() > 0);

  // Add penultimate entry.
  dls.addDeadline(0, BufferOffset(25));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
  CHECK(dls.earliestDeadlineRange() > 0);

  // Prepend, stealing earliest from other range.
  dls.addDeadline(0, BufferOffset(5));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 5);
  CHECK_EQUAL(dls.earliestDeadlineRange(), 0u);

  // Remove central element.
  dls.removeDeadline(0, BufferOffset(20));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 5);
  CHECK_EQUAL(dls.earliestDeadlineRange(), 0u);

  // Remove front, giving back the lead.
  dls.removeDeadline(0, BufferOffset(5));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 10);
  CHECK(dls.earliestDeadlineRange() > 0);

  // Remove front, giving back earliest to range 0.
  dls.removeDeadline(dls.earliestDeadlineRange(), BufferOffset(10));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 15);
  CHECK_EQUAL(dls.earliestDeadlineRange(), 0u);

  // Remove tail.
  dls.removeDeadline(0, BufferOffset(30));
  CHECK_EQUAL(dls.earliestDeadline().getOffset(), 15);
  CHECK_EQUAL(dls.earliestDeadlineRange(), 0u);

  // Now range 0 = [15, 25].
  CHECK_EQUAL(dls.size(), 2u);
  dls.removeDeadline(0, BufferOffset(25));
  dls.removeDeadline(0, BufferOffset(15));
  CHECK(dls.empty());

  return true;
}
END_TEST(testAssemblerBuffer_BranchDeadlineSet)

// Mock Assembler class for testing the AssemblerBufferWithConstantPools
// callbacks.
namespace {

struct TestAssembler;

using AsmBufWithPool = js::jit::AssemblerBufferWithConstantPools<
    /* SliceSize */ 5 * sizeof(uint32_t),
    /* InstSize */ 4,
    /* Inst */ uint32_t,
    /* Asm */ TestAssembler,
    /* NumShortBranchRanges */ 3>;

struct TestAssembler {
  // Mock instruction set:
  //
  //   0x1111xxxx - align filler instructions.
  //   0x2222xxxx - manually inserted 'arith' instructions.
  //   0xaaaaxxxx - noop filler instruction.
  //   0xb0bbxxxx - branch xxxx bytes forward. (Pool guard).
  //   0xb1bbxxxx - branch xxxx bytes forward. (Short-range branch).
  //   0xb2bbxxxx - branch xxxx bytes forward. (Veneer branch).
  //   0xb3bbxxxx - branch xxxx bytes forward. (Patched short-range branch).
  //   0xc0ccxxxx - constant pool load (uninitialized).
  //   0xc1ccxxxx - constant pool load to index xxxx.
  //   0xc2ccxxxx - constant pool load xxxx bytes ahead.
  //   0xffffxxxx - pool header with xxxx bytes.

  static const unsigned BranchRange = 36;

  static void InsertIndexIntoTag(uint8_t* load_, uint32_t index) {
    uint32_t* load = reinterpret_cast<uint32_t*>(load_);
    MOZ_ASSERT(*load == 0xc0cc0000,
               "Expected uninitialized constant pool load");
    MOZ_ASSERT(index < 0x10000);
    *load = 0xc1cc0000 + index;
  }

  static void PatchConstantPoolLoad(void* loadAddr, void* constPoolAddr) {
    uint32_t* load = reinterpret_cast<uint32_t*>(loadAddr);
    uint32_t index = *load & 0xffff;
    MOZ_ASSERT(*load == (0xc1cc0000 | index),
               "Expected constant pool load(index)");
    ptrdiff_t offset = reinterpret_cast<uint8_t*>(constPoolAddr) -
                       reinterpret_cast<uint8_t*>(loadAddr);
    offset += index * 4;
    MOZ_ASSERT(offset % 4 == 0, "Unaligned constant pool");
    MOZ_ASSERT(offset > 0 && offset < 0x10000, "Pool out of range");
    *load = 0xc2cc0000 + offset;
  }

  static void WritePoolGuard(js::jit::BufferOffset branch, uint32_t* dest,
                             js::jit::BufferOffset afterPool) {
    MOZ_ASSERT(branch.assigned());
    MOZ_ASSERT(afterPool.assigned());
    size_t branchOff = branch.getOffset();
    size_t afterPoolOff = afterPool.getOffset();
    MOZ_ASSERT(afterPoolOff > branchOff);
    uint32_t delta = afterPoolOff - branchOff;
    *dest = 0xb0bb0000 + delta;
  }

  static void WritePoolHeader(void* start, js::jit::Pool* p, bool isNatural) {
    MOZ_ASSERT(!isNatural, "Natural pool guards not implemented.");
    uint32_t* hdr = reinterpret_cast<uint32_t*>(start);
    *hdr = 0xffff0000 + p->getPoolSize();
  }

  static void PatchShortRangeBranchToVeneer(AsmBufWithPool* buffer,
                                            unsigned rangeIdx,
                                            js::jit::BufferOffset deadline,
                                            js::jit::BufferOffset veneer) {
    size_t branchOff = deadline.getOffset() - BranchRange;
    size_t veneerOff = veneer.getOffset();
    uint32_t* branch = buffer->getInst(js::jit::BufferOffset(branchOff));

    MOZ_ASSERT((*branch & 0xffff0000) == 0xb1bb0000,
               "Expected short-range branch instruction");
    // Copy branch offset to veneer. A real instruction set would require
    // some adjustment of the label linked-list.
    *buffer->getInst(veneer) = 0xb2bb0000 | (*branch & 0xffff);
    MOZ_ASSERT(veneerOff > branchOff, "Veneer should follow branch");
    *branch = 0xb3bb0000 + (veneerOff - branchOff);
  }
};
}  // namespace

BEGIN_TEST(testAssemblerBuffer_AssemblerBufferWithConstantPools) {
  using js::jit::BufferOffset;

  AsmBufWithPool ab(/* guardSize= */ 1,
                    /* headerSize= */ 1,
                    /* instBufferAlign(unused)= */ 0,
                    /* poolMaxOffset= */ 17,
                    /* pcBias= */ 0,
                    /* alignFillInst= */ 0x11110000,
                    /* nopFillInst= */ 0xaaaa0000,
                    /* nopFill= */ 0);

  CHECK(ab.isAligned(16));
  CHECK_EQUAL(ab.size(), 0u);
  CHECK_EQUAL(ab.nextOffset().getOffset(), 0);
  CHECK(!ab.oom());

  // Each slice holds 5 instructions. Trigger a constant pool inside the slice.
  uint32_t poolLoad[] = {0xc0cc0000};
  uint32_t poolData[] = {0xdddd0000, 0xdddd0001, 0xdddd0002, 0xdddd0003};
  AsmBufWithPool::PoolEntry pe;
  BufferOffset load =
      ab.allocEntry(1, 1, (uint8_t*)poolLoad, (uint8_t*)poolData, &pe);
  CHECK_EQUAL(pe.index(), 0u);
  CHECK_EQUAL(load.getOffset(), 0);

  // Pool hasn't been emitted yet. Load has been patched by
  // InsertIndexIntoTag.
  CHECK_EQUAL(*ab.getInst(load), 0xc1cc0000);

  // Expected layout:
  //
  //   0: load [pc+16]
  //   4: 0x22220001
  //   8: guard branch pc+12
  //  12: pool header
  //  16: poolData
  //  20: 0x22220002
  //
  ab.putInt(0x22220001);
  // One could argue that the pool should be flushed here since there is no
  // more room. However, the current implementation doesn't dump pool until
  // asked to add data:
  ab.putInt(0x22220002);

  CHECK_EQUAL(*ab.getInst(BufferOffset(0)), 0xc2cc0010u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(4)), 0x22220001u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(8)), 0xb0bb000cu);
  CHECK_EQUAL(*ab.getInst(BufferOffset(12)), 0xffff0004u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(16)), 0xdddd0000u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(20)), 0x22220002u);

  // allocEntry() overwrites the load instruction! Restore the original.
  poolLoad[0] = 0xc0cc0000;

  // Now try with load and pool data on separate slices.
  load = ab.allocEntry(1, 1, (uint8_t*)poolLoad, (uint8_t*)poolData, &pe);
  CHECK_EQUAL(pe.index(), 1u);  // Global pool entry index.
  CHECK_EQUAL(load.getOffset(), 24);
  CHECK_EQUAL(*ab.getInst(load), 0xc1cc0000);  // Index into current pool.
  ab.putInt(0x22220001);
  ab.putInt(0x22220002);
  CHECK_EQUAL(*ab.getInst(BufferOffset(24)), 0xc2cc0010u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(28)), 0x22220001u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(32)), 0xb0bb000cu);
  CHECK_EQUAL(*ab.getInst(BufferOffset(36)), 0xffff0004u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(40)), 0xdddd0000u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(44)), 0x22220002u);

  // Two adjacent loads to the same pool.
  poolLoad[0] = 0xc0cc0000;
  load = ab.allocEntry(1, 1, (uint8_t*)poolLoad, (uint8_t*)poolData, &pe);
  CHECK_EQUAL(pe.index(), 2u);  // Global pool entry index.
  CHECK_EQUAL(load.getOffset(), 48);
  CHECK_EQUAL(*ab.getInst(load), 0xc1cc0000);  // Index into current pool.

  poolLoad[0] = 0xc0cc0000;
  load = ab.allocEntry(1, 1, (uint8_t*)poolLoad, (uint8_t*)(poolData + 1), &pe);
  CHECK_EQUAL(pe.index(), 3u);  // Global pool entry index.
  CHECK_EQUAL(load.getOffset(), 52);
  CHECK_EQUAL(*ab.getInst(load), 0xc1cc0001);  // Index into current pool.

  ab.putInt(0x22220005);

  CHECK_EQUAL(*ab.getInst(BufferOffset(48)), 0xc2cc0010u);  // load pc+16.
  CHECK_EQUAL(*ab.getInst(BufferOffset(52)), 0xc2cc0010u);  // load pc+16.
  CHECK_EQUAL(*ab.getInst(BufferOffset(56)),
              0xb0bb0010u);  // guard branch pc+16.
  CHECK_EQUAL(*ab.getInst(BufferOffset(60)), 0xffff0008u);  // header 8 bytes.
  CHECK_EQUAL(*ab.getInst(BufferOffset(64)), 0xdddd0000u);  // datum 1.
  CHECK_EQUAL(*ab.getInst(BufferOffset(68)), 0xdddd0001u);  // datum 2.
  CHECK_EQUAL(*ab.getInst(BufferOffset(72)),
              0x22220005u);  // putInt(0x22220005)

  // Two loads as above, but the first load has an 8-byte pool entry, and the
  // second load wouldn't be able to reach its data. This must produce two
  // pools.
  poolLoad[0] = 0xc0cc0000;
  load = ab.allocEntry(1, 2, (uint8_t*)poolLoad, (uint8_t*)(poolData + 2), &pe);
  CHECK_EQUAL(pe.index(), 4u);  // Global pool entry index.
  CHECK_EQUAL(load.getOffset(), 76);
  CHECK_EQUAL(*ab.getInst(load), 0xc1cc0000);  // Index into current pool.

  poolLoad[0] = 0xc0cc0000;
  load = ab.allocEntry(1, 1, (uint8_t*)poolLoad, (uint8_t*)poolData, &pe);
  CHECK_EQUAL(pe.index(),
              6u);  // Global pool entry index. (Prev one is two indexes).
  CHECK_EQUAL(load.getOffset(), 96);
  CHECK_EQUAL(*ab.getInst(load), 0xc1cc0000);  // Index into current pool.

  CHECK_EQUAL(*ab.getInst(BufferOffset(76)), 0xc2cc000cu);  // load pc+12.
  CHECK_EQUAL(*ab.getInst(BufferOffset(80)),
              0xb0bb0010u);  // guard branch pc+16.
  CHECK_EQUAL(*ab.getInst(BufferOffset(84)), 0xffff0008u);  // header 8 bytes.
  CHECK_EQUAL(*ab.getInst(BufferOffset(88)), 0xdddd0002u);  // datum 1.
  CHECK_EQUAL(*ab.getInst(BufferOffset(92)), 0xdddd0003u);  // datum 2.

  // Second pool is not flushed yet, and there is room for one instruction
  // after the load. Test the keep-together feature.
  ab.enterNoPool(2);
  ab.putInt(0x22220006);
  ab.putInt(0x22220007);
  ab.leaveNoPool();

  CHECK_EQUAL(*ab.getInst(BufferOffset(96)), 0xc2cc000cu);  // load pc+16.
  CHECK_EQUAL(*ab.getInst(BufferOffset(100)),
              0xb0bb000cu);  // guard branch pc+12.
  CHECK_EQUAL(*ab.getInst(BufferOffset(104)), 0xffff0004u);  // header 4 bytes.
  CHECK_EQUAL(*ab.getInst(BufferOffset(108)), 0xdddd0000u);  // datum 1.
  CHECK_EQUAL(*ab.getInst(BufferOffset(112)), 0x22220006u);
  CHECK_EQUAL(*ab.getInst(BufferOffset(116)), 0x22220007u);

  return true;
}
END_TEST(testAssemblerBuffer_AssemblerBufferWithConstantPools)

BEGIN_TEST(testAssemblerBuffer_AssemblerBufferWithConstantPools_ShortBranch) {
  using js::jit::BufferOffset;

  AsmBufWithPool ab(/* guardSize= */ 1,
                    /* headerSize= */ 1,
                    /* instBufferAlign(unused)= */ 0,
                    /* poolMaxOffset= */ 17,
                    /* pcBias= */ 0,
                    /* alignFillInst= */ 0x11110000,
                    /* nopFillInst= */ 0xaaaa0000,
                    /* nopFill= */ 0);

  // Insert short-range branch.
  BufferOffset br1 = ab.putInt(0xb1bb00cc);
  ab.registerBranchDeadline(
      1, BufferOffset(br1.getOffset() + TestAssembler::BranchRange));
  ab.putInt(0x22220001);
  BufferOffset off = ab.putInt(0x22220002);
  ab.registerBranchDeadline(
      1, BufferOffset(off.getOffset() + TestAssembler::BranchRange));
  ab.putInt(0x22220003);
  ab.putInt(0x22220004);

  // Second short-range branch that will be swiped up by hysteresis.
  BufferOffset br2 = ab.putInt(0xb1bb0d2d);
  ab.registerBranchDeadline(
      1, BufferOffset(br2.getOffset() + TestAssembler::BranchRange));

  // Branch should not have been patched yet here.
  CHECK_EQUAL(*ab.getInst(br1), 0xb1bb00cc);
  CHECK_EQUAL(*ab.getInst(br2), 0xb1bb0d2d);

  // Cancel one of the pending branches.
  // This is what will happen to most branches as they are bound before
  // expiring by Assembler::bind().
  ab.unregisterBranchDeadline(
      1, BufferOffset(off.getOffset() + TestAssembler::BranchRange));

  off = ab.putInt(0x22220006);
  // Here we may or may not have patched the branch yet, but it is inevitable
  // now:
  //
  //  0: br1 pc+36
  //  4: 0x22220001
  //  8: 0x22220002 (unpatched)
  // 12: 0x22220003
  // 16: 0x22220004
  // 20: br2 pc+20
  // 24: 0x22220006
  CHECK_EQUAL(off.getOffset(), 24);
  // 28: guard branch pc+16
  // 32: pool header
  // 36: veneer1
  // 40: veneer2
  // 44: 0x22220007

  off = ab.putInt(0x22220007);
  CHECK_EQUAL(off.getOffset(), 44);

  // Now the branch must have been patched.
  CHECK_EQUAL(*ab.getInst(br1), 0xb3bb0000 + 36);  // br1 pc+36 (patched)
  CHECK_EQUAL(*ab.getInst(BufferOffset(8)),
              0x22220002u);                        // 0x22220002 (unpatched)
  CHECK_EQUAL(*ab.getInst(br2), 0xb3bb0000 + 20);  // br2 pc+20 (patched)
  CHECK_EQUAL(*ab.getInst(BufferOffset(28)), 0xb0bb0010u);  // br pc+16 (guard)
  CHECK_EQUAL(*ab.getInst(BufferOffset(32)),
              0xffff0000u);  // pool header 0 bytes.
  CHECK_EQUAL(*ab.getInst(BufferOffset(36)),
              0xb2bb00ccu);  // veneer1 w/ original 'cc' offset.
  CHECK_EQUAL(*ab.getInst(BufferOffset(40)),
              0xb2bb0d2du);  // veneer2 w/ original 'd2d' offset.
  CHECK_EQUAL(*ab.getInst(BufferOffset(44)), 0x22220007u);

  return true;
}
END_TEST(testAssemblerBuffer_AssemblerBufferWithConstantPools_ShortBranch)

// Test that everything is put together correctly in the ARM64 assembler.
#if defined(JS_CODEGEN_ARM64)

#  include "jit/MacroAssembler-inl.h"

BEGIN_TEST(testAssemblerBuffer_ARM64) {
  using namespace js::jit;

  js::LifoAlloc lifo(4096, js::MallocArena);
  TempAllocator alloc(&lifo);
  JitContext jc(cx);
  StackMacroAssembler masm(cx, alloc);
  AutoCreatedBy acb(masm, __func__);

  // Branches to an unbound label.
  Label lab1;
  masm.branch(Assembler::Equal, &lab1);
  masm.branch(Assembler::LessThan, &lab1);
  masm.bind(&lab1);
  masm.branch(Assembler::Equal, &lab1);

  CHECK_EQUAL(masm.getInstructionAt(BufferOffset(0))->InstructionBits(),
              vixl::B_cond | vixl::Assembler::ImmCondBranch(2) | vixl::eq);
  CHECK_EQUAL(masm.getInstructionAt(BufferOffset(4))->InstructionBits(),
              vixl::B_cond | vixl::Assembler::ImmCondBranch(1) | vixl::lt);
  CHECK_EQUAL(masm.getInstructionAt(BufferOffset(8))->InstructionBits(),
              vixl::B_cond | vixl::Assembler::ImmCondBranch(0) | vixl::eq);

  // Branches can reach the label, but the linked list of uses needs to be
  // rearranged. The final conditional branch cannot reach the first branch.
  Label lab2a;
  Label lab2b;
  masm.bind(&lab2a);
  masm.B(&lab2b);
  // Generate 1,100,000 bytes of NOPs.
  for (unsigned n = 0; n < 1100000; n += 4) {
    masm.Nop();
  }
  masm.branch(Assembler::LessThan, &lab2b);
  masm.bind(&lab2b);
  CHECK_EQUAL(
      masm.getInstructionAt(BufferOffset(lab2a.offset()))->InstructionBits(),
      vixl::B | vixl::Assembler::ImmUncondBranch(1100000 / 4 + 2));
  CHECK_EQUAL(masm.getInstructionAt(BufferOffset(lab2b.offset() - 4))
                  ->InstructionBits(),
              vixl::B_cond | vixl::Assembler::ImmCondBranch(1) | vixl::lt);

  // Generate a conditional branch that can't reach its label.
  Label lab3a;
  Label lab3b;
  masm.bind(&lab3a);
  masm.branch(Assembler::LessThan, &lab3b);
  for (unsigned n = 0; n < 1100000; n += 4) {
    masm.Nop();
  }
  masm.bind(&lab3b);
  masm.B(&lab3a);
  Instruction* bcond3 = masm.getInstructionAt(BufferOffset(lab3a.offset()));
  CHECK_EQUAL(bcond3->BranchType(), vixl::CondBranchType);
  ptrdiff_t delta = bcond3->ImmPCRawOffset() * 4;
  Instruction* veneer =
      masm.getInstructionAt(BufferOffset(lab3a.offset() + delta));
  CHECK_EQUAL(veneer->BranchType(), vixl::UncondBranchType);
  delta += veneer->ImmPCRawOffset() * 4;
  CHECK_EQUAL(delta, lab3b.offset() - lab3a.offset());
  Instruction* b3 = masm.getInstructionAt(BufferOffset(lab3b.offset()));
  CHECK_EQUAL(b3->BranchType(), vixl::UncondBranchType);
  CHECK_EQUAL(4 * b3->ImmPCRawOffset(), -delta);

  return true;
}
END_TEST(testAssemblerBuffer_ARM64)
#endif /* JS_CODEGEN_ARM64 */

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NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.