--- a/src/hotspot/cpu/ppc/templateTable_ppc_64.cpp Thu Dec 21 00:07:38 2017 +0100
+++ b/src/hotspot/cpu/ppc/templateTable_ppc_64.cpp Wed Dec 20 11:00:07 2017 -0800
@@ -3634,10 +3634,7 @@
transition(vtos, atos);
Label Lslow_case,
- Ldone,
- Linitialize_header,
- Lallocate_shared,
- Linitialize_object; // Including clearing the fields.
+ Ldone;
const Register RallocatedObject = R17_tos,
RinstanceKlass = R9_ARG7,
@@ -3648,8 +3645,6 @@
Rtags = R3_ARG1,
Rindex = R5_ARG3;
- const bool allow_shared_alloc = Universe::heap()->supports_inline_contig_alloc();
-
// --------------------------------------------------------------------------
// Check if fast case is possible.
@@ -3658,6 +3653,8 @@
// Load index of constant pool entry.
__ get_2_byte_integer_at_bcp(1, Rindex, InterpreterMacroAssembler::Unsigned);
+ // Note: compared to other architectures, PPC's implementation always goes
+ // to the slow path if TLAB is used and fails.
if (UseTLAB) {
// Make sure the class we're about to instantiate has been resolved
// This is done before loading instanceKlass to be consistent with the order
@@ -3687,8 +3684,7 @@
// Fast case:
// Allocate the instance.
// 1) Try to allocate in the TLAB.
- // 2) If fail, and the TLAB is not full enough to discard, allocate in the shared Eden.
- // 3) If the above fails (or is not applicable), go to a slow case (creates a new TLAB, etc.).
+ // 2) If the above fails (or is not applicable), go to a slow case (creates a new TLAB, etc.).
Register RoldTopValue = RallocatedObject; // Object will be allocated here if it fits.
Register RnewTopValue = R6_ARG4;
@@ -3702,53 +3698,13 @@
// If there is enough space, we do not CAS and do not clear.
__ cmpld(CCR0, RnewTopValue, RendValue);
- __ bgt(CCR0, allow_shared_alloc ? Lallocate_shared : Lslow_case);
+ __ bgt(CCR0, Lslow_case);
__ std(RnewTopValue, in_bytes(JavaThread::tlab_top_offset()), R16_thread);
- if (ZeroTLAB) {
- // The fields have already been cleared.
- __ b(Linitialize_header);
- } else {
- // Initialize both the header and fields.
- __ b(Linitialize_object);
- }
-
- // Fall through: TLAB was too small.
- if (allow_shared_alloc) {
- Register RtlabWasteLimitValue = R10_ARG8;
- Register RfreeValue = RnewTopValue;
-
- __ bind(Lallocate_shared);
- // Check if tlab should be discarded (refill_waste_limit >= free).
- __ ld(RtlabWasteLimitValue, in_bytes(JavaThread::tlab_refill_waste_limit_offset()), R16_thread);
- __ subf(RfreeValue, RoldTopValue, RendValue);
- __ srdi(RfreeValue, RfreeValue, LogHeapWordSize); // in dwords
- __ cmpld(CCR0, RtlabWasteLimitValue, RfreeValue);
- __ bge(CCR0, Lslow_case);
-
- // Increment waste limit to prevent getting stuck on this slow path.
- __ add_const_optimized(RtlabWasteLimitValue, RtlabWasteLimitValue, ThreadLocalAllocBuffer::refill_waste_limit_increment());
- __ std(RtlabWasteLimitValue, in_bytes(JavaThread::tlab_refill_waste_limit_offset()), R16_thread);
- }
- // else: No allocation in the shared eden. // fallthru: __ b(Lslow_case);
- }
- // else: Always go the slow path.
-
- // --------------------------------------------------------------------------
- // slow case
- __ bind(Lslow_case);
- call_VM(R17_tos, CAST_FROM_FN_PTR(address, InterpreterRuntime::_new), Rcpool, Rindex);
-
- if (UseTLAB) {
- __ b(Ldone);
- // --------------------------------------------------------------------------
- // Init1: Zero out newly allocated memory.
-
- if (!ZeroTLAB || allow_shared_alloc) {
- // Clear object fields.
- __ bind(Linitialize_object);
-
+ if (!ZeroTLAB) {
+ // --------------------------------------------------------------------------
+ // Init1: Zero out newly allocated memory.
// Initialize remaining object fields.
Register Rbase = Rtags;
__ addi(Rinstance_size, Rinstance_size, 7 - (int)sizeof(oopDesc));
@@ -3757,13 +3713,10 @@
// Clear out object skipping header. Takes also care of the zero length case.
__ clear_memory_doubleword(Rbase, Rinstance_size);
- // fallthru: __ b(Linitialize_header);
}
// --------------------------------------------------------------------------
// Init2: Initialize the header: mark, klass
- __ bind(Linitialize_header);
-
// Init mark.
if (UseBiasedLocking) {
__ ld(Rscratch, in_bytes(Klass::prototype_header_offset()), RinstanceKlass);
@@ -3777,14 +3730,19 @@
__ store_klass(RallocatedObject, RinstanceKlass, Rscratch); // klass (last for cms)
// Check and trigger dtrace event.
- {
- SkipIfEqualZero skip_if(_masm, Rscratch, &DTraceAllocProbes);
- __ push(atos);
- __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc));
- __ pop(atos);
- }
+ SkipIfEqualZero::skip_to_label_if_equal_zero(_masm, Rscratch, &DTraceAllocProbes, Ldone);
+ __ push(atos);
+ __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc));
+ __ pop(atos);
+
+ __ b(Ldone);
}
+ // --------------------------------------------------------------------------
+ // slow case
+ __ bind(Lslow_case);
+ call_VM(R17_tos, CAST_FROM_FN_PTR(address, InterpreterRuntime::_new), Rcpool, Rindex);
+
// continue
__ bind(Ldone);