Skip to content

8360775: Fix Shenandoah GC test failures when APX is enabled #26009

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 2 commits into from
+41 −1
Closed

8360775: Fix Shenandoah GC test failures when APX is enabled #26009

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
2dba6e3
8360775: Fix Shenandoah GC test failures when APX is enabled
vamsi-parasa Jun 26, 2025
de7c373
restore the orginal contents of rax
vamsi-parasa Jun 30, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions src/hotspot/cpu/x86/assembler_x86.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15681,6 +15681,8 @@ void Assembler::pusha_uncached() { // 64bit
// Push pair of original stack pointer along with remaining registers
// at 16B aligned boundary.
push2p(rax, r31);
// Restore the original contents of RAX register.
movq(rax, Address(rax));
push2p(r30, r29);
push2p(r28, r27);
push2p(r26, r25);
Expand Down
40 changes: 39 additions & 1 deletion src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -353,7 +353,7 @@ void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm,

// The rest is saved with the optimized path

uint num_saved_regs = 4 + (dst != rax ? 1 : 0) + 4;
uint num_saved_regs = 4 + (dst != rax ? 1 : 0) + 4 + (UseAPX ? 16 : 0);
__ subptr(rsp, num_saved_regs * wordSize);
uint slot = num_saved_regs;
if (dst != rax) {
Expand All @@ -367,6 +367,25 @@ void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm,
__ movptr(Address(rsp, (--slot) * wordSize), r9);
__ movptr(Address(rsp, (--slot) * wordSize), r10);
__ movptr(Address(rsp, (--slot) * wordSize), r11);
// Save APX extended registers r16–r31 if enabled
if (UseAPX) {
__ movptr(Address(rsp, (--slot) * wordSize), r16);
__ movptr(Address(rsp, (--slot) * wordSize), r17);
__ movptr(Address(rsp, (--slot) * wordSize), r18);
__ movptr(Address(rsp, (--slot) * wordSize), r19);
__ movptr(Address(rsp, (--slot) * wordSize), r20);
__ movptr(Address(rsp, (--slot) * wordSize), r21);
__ movptr(Address(rsp, (--slot) * wordSize), r22);
__ movptr(Address(rsp, (--slot) * wordSize), r23);
__ movptr(Address(rsp, (--slot) * wordSize), r24);
__ movptr(Address(rsp, (--slot) * wordSize), r25);
__ movptr(Address(rsp, (--slot) * wordSize), r26);
__ movptr(Address(rsp, (--slot) * wordSize), r27);
__ movptr(Address(rsp, (--slot) * wordSize), r28);
__ movptr(Address(rsp, (--slot) * wordSize), r29);
__ movptr(Address(rsp, (--slot) * wordSize), r30);
__ movptr(Address(rsp, (--slot) * wordSize), r31);
Comment on lines +372 to +387
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think you should use pushp2 / pop2p for these instructions also , maybe it can be handled along with
#25889

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks Jatin (@jatin-bhateja) for the review and approval! This modification will be pursued in another PR (say #25889).

}
// r12-r15 are callee saved in all calling conventions
assert(slot == 0, "must use all slots");

Expand Down Expand Up @@ -398,6 +417,25 @@ void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm,
__ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_phantom), arg0, arg1);
}

// Restore APX extended registers r31–r16 if previously saved
if (UseAPX) {
__ movptr(r31, Address(rsp, (slot++) * wordSize));
__ movptr(r30, Address(rsp, (slot++) * wordSize));
__ movptr(r29, Address(rsp, (slot++) * wordSize));
__ movptr(r28, Address(rsp, (slot++) * wordSize));
__ movptr(r27, Address(rsp, (slot++) * wordSize));
__ movptr(r26, Address(rsp, (slot++) * wordSize));
__ movptr(r25, Address(rsp, (slot++) * wordSize));
__ movptr(r24, Address(rsp, (slot++) * wordSize));
__ movptr(r23, Address(rsp, (slot++) * wordSize));
__ movptr(r22, Address(rsp, (slot++) * wordSize));
__ movptr(r21, Address(rsp, (slot++) * wordSize));
__ movptr(r20, Address(rsp, (slot++) * wordSize));
__ movptr(r19, Address(rsp, (slot++) * wordSize));
__ movptr(r18, Address(rsp, (slot++) * wordSize));
__ movptr(r17, Address(rsp, (slot++) * wordSize));
__ movptr(r16, Address(rsp, (slot++) * wordSize));
}
__ movptr(r11, Address(rsp, (slot++) * wordSize));
__ movptr(r10, Address(rsp, (slot++) * wordSize));
__ movptr(r9, Address(rsp, (slot++) * wordSize));
Expand Down