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[arm] Fix --enable-vldr-imm.

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This fixes several bugs related to float64 pool constants.

Note that float64 pool constants are still disabled by default, and are
only used if --enable-vldr-imm is provided.

BUG=

Review URL: https://codereview.chromium.org/1260953002

Cr-Commit-Position: refs/heads/master@{#29917}
This commit is contained in:
jacob.bramley 2015-07-30 02:11:12 -07:00 committed by Commit bot
parent c9ed8f9751
commit def8647344
1 changed files with 32 additions and 23 deletions
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47
src/arm/assembler-arm.cc
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@ -2573,6 +2573,12 @@ void Assembler::vmov(const DwVfpRegister dst,
double imm,
const Register scratch) {
uint32_t enc;
// If the embedded constant pool is disabled, we can use the normal, inline
// constant pool. If the embedded constant pool is enabled (via
// FLAG_enable_embedded_constant_pool), we can only use it where the pool
// pointer (pp) is valid.
bool can_use_pool =
!FLAG_enable_embedded_constant_pool || is_constant_pool_available();
if (CpuFeatures::IsSupported(VFP3) && FitsVMOVDoubleImmediate(imm, &enc)) {
// The double can be encoded in the instruction.
//
@ -2583,7 +2589,7 @@ void Assembler::vmov(const DwVfpRegister dst,
int vd, d;
dst.split_code(&vd, &d);
emit(al | 0x1D*B23 | d*B22 | 0x3*B20 | vd*B12 | 0x5*B9 | B8 | enc);
} else if (FLAG_enable_vldr_imm && is_constant_pool_available()) {
} else if (FLAG_enable_vldr_imm && can_use_pool) {
// TODO(jfb) Temporarily turned off until we have constant blinding or
// some equivalent mitigation: an attacker can otherwise control
// generated data which also happens to be executable, a Very Bad
@ -3588,11 +3594,10 @@ void Assembler::GrowBuffer() {
void Assembler::db(uint8_t data) {
// No relocation info should be pending while using db. db is used
// to write pure data with no pointers and the constant pool should
// be emitted before using db.
DCHECK(num_pending_32_bit_constants_ == 0);
DCHECK(num_pending_64_bit_constants_ == 0);
// db is used to write raw data. The constant pool should be emitted or
// blocked before using db.
DCHECK(is_const_pool_blocked() || (num_pending_32_bit_constants_ == 0));
DCHECK(is_const_pool_blocked() || (num_pending_64_bit_constants_ == 0));
CheckBuffer();
*reinterpret_cast<uint8_t*>(pc_) = data;
pc_ += sizeof(uint8_t);
@ -3600,11 +3605,10 @@ void Assembler::db(uint8_t data) {
void Assembler::dd(uint32_t data) {
// No relocation info should be pending while using dd. dd is used
// to write pure data with no pointers and the constant pool should
// be emitted before using dd.
DCHECK(num_pending_32_bit_constants_ == 0);
DCHECK(num_pending_64_bit_constants_ == 0);
// dd is used to write raw data. The constant pool should be emitted or
// blocked before using dd.
DCHECK(is_const_pool_blocked() || (num_pending_32_bit_constants_ == 0));
DCHECK(is_const_pool_blocked() || (num_pending_64_bit_constants_ == 0));
CheckBuffer();
*reinterpret_cast<uint32_t*>(pc_) = data;
pc_ += sizeof(uint32_t);
@ -3612,11 +3616,10 @@ void Assembler::dd(uint32_t data) {
void Assembler::dq(uint64_t value) {
// No relocation info should be pending while using dq. dq is used
// to write pure data with no pointers and the constant pool should
// be emitted before using dd.
DCHECK(num_pending_32_bit_constants_ == 0);
DCHECK(num_pending_64_bit_constants_ == 0);
// dq is used to write raw data. The constant pool should be emitted or
// blocked before using dq.
DCHECK(is_const_pool_blocked() || (num_pending_32_bit_constants_ == 0));
DCHECK(is_const_pool_blocked() || (num_pending_64_bit_constants_ == 0));
CheckBuffer();
*reinterpret_cast<uint64_t*>(pc_) = value;
pc_ += sizeof(uint64_t);
@ -3755,11 +3758,13 @@ void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
int size_up_to_marker = jump_instr + kInstrSize;
int estimated_size_after_marker =
num_pending_32_bit_constants_ * kPointerSize;
bool has_int_values = (num_pending_32_bit_constants_ > 0);
bool has_fp_values = (num_pending_64_bit_constants_ > 0);
bool require_64_bit_align = false;
if (has_fp_values) {
require_64_bit_align = IsAligned(
reinterpret_cast<intptr_t>(pc_ + size_up_to_marker), kDoubleAlignment);
require_64_bit_align =
!IsAligned(reinterpret_cast<intptr_t>(pc_ + size_up_to_marker),
kDoubleAlignment);
if (require_64_bit_align) {
estimated_size_after_marker += kInstrSize;
}
@ -3776,9 +3781,11 @@ void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
// * the instruction doesn't require a jump after itself to jump over the
// constant pool, and we're getting close to running out of range.
if (!force_emit) {
DCHECK((first_const_pool_32_use_ >= 0) || (first_const_pool_64_use_ >= 0));
DCHECK(has_fp_values || has_int_values);
bool need_emit = false;
if (has_fp_values) {
// The 64-bit constants are always emitted before the 32-bit constants, so
// we can ignore the effect of the 32-bit constants on estimated_size.
int dist64 = pc_offset() + estimated_size -
num_pending_32_bit_constants_ * kPointerSize -
first_const_pool_64_use_;
@ -3787,11 +3794,13 @@ void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
need_emit = true;
}
}
if (has_int_values) {
int dist32 = pc_offset() + estimated_size - first_const_pool_32_use_;
if ((dist32 >= kMaxDistToIntPool - kCheckPoolInterval) ||
(!require_jump && (dist32 >= kMaxDistToIntPool / 2))) {
need_emit = true;
}
}
if (!need_emit) return;
}