Port r12373 (
9fdde2ad)
Original commit message:
Fix DoDeferredNumberTagU to keep the value in xmm1 instead of xmm0 on x64.
xmm0 is not saved across runtime call on x64 because MacroAssembler::EnterExitFrameEpilogue preserves only allocatable XMM registers unlike on ia32 where it preserves all registers.
Cleanup handling of shifts: SHR can deoptimize only when its a shift by 0, all other shift never deoptimize.
Fix type inference for i-to-t change instruction. On X64 this ensures that write-barrier is generated correctly.
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/
10876054
Patch from Akos Palfi <palfia@homejinni.com>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12831
ce2b1a6d-e550-0410-aec6-
3dcde31c8c00
right = UseRegisterAtStart(right_value);
}
+ // Shift operations can only deoptimize if we do a logical shift
+ // by 0 and the result cannot be truncated to int32.
bool does_deopt = false;
-
- if (FLAG_opt_safe_uint32_operations) {
- does_deopt = !instr->CheckFlag(HInstruction::kUint32);
- } else {
- // Shift operations can only deoptimize if we do a logical shift
- // by 0 and the result cannot be truncated to int32.
- bool may_deopt = (op == Token::SHR && constant_value == 0);
- if (may_deopt) {
+ if (op == Token::SHR && constant_value == 0) {
+ if (FLAG_opt_safe_uint32_operations) {
+ does_deopt = !instr->CheckFlag(HInstruction::kUint32);
+ } else {
for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
if (!it.value()->CheckFlag(HValue::kTruncatingToInt32)) {
does_deopt = true;