|
 |
dc9548 |
# HG changeset patch
|
|
|
dc9548 |
# User Lars T Hansen <lhansen@mozilla.com>
|
|
|
dc9548 |
# Date 1519822672 -3600
|
|
|
dc9548 |
# Node ID 800abe66894d6b07b24bccecbf6a65e2261076f6
|
|
|
dc9548 |
# Parent 223c97459e96183eb616aed39147207bdb953ba8
|
|
|
dc9548 |
Bug 1375074 - Save and restore non-volatile x28 on ARM64 for generated unboxed object constructor. r=sstangl
|
|
|
dc9548 |
|
|
|
dc9548 |
Origin: upstream
|
|
|
dc9548 |
Applied-upstream: 61, commit: https://hg.mozilla.org/mozilla-central/rev/800abe66894d
|
|
|
dc9548 |
---
|
|
|
dc9548 |
js/src/vm/UnboxedObject.cpp | 30 ++++++++++++++++++++++++++----
|
|
|
dc9548 |
1 file changed, 26 insertions(+), 4 deletions(-)
|
|
|
dc9548 |
|
|
|
dc9548 |
diff --git a/js/src/vm/UnboxedObject.cpp b/js/src/vm/UnboxedObject.cpp
|
|
|
dc9548 |
index 35ca20d7405f..1c20a1093d13 100644
|
|
|
dc9548 |
--- a/js/src/vm/UnboxedObject.cpp
|
|
|
dc9548 |
+++ b/js/src/vm/UnboxedObject.cpp
|
|
|
dc9548 |
@@ -86,9 +86,16 @@ static const uintptr_t CLEAR_CONSTRUCTOR_CODE_TOKEN = 0x1;
|
|
|
dc9548 |
#endif
|
|
|
dc9548 |
|
|
|
dc9548 |
#ifdef JS_CODEGEN_ARM64
|
|
|
dc9548 |
- // ARM64 communicates stack address via sp, but uses a pseudo-sp for
|
|
|
dc9548 |
- // addressing.
|
|
|
dc9548 |
- masm.initStackPtr();
|
|
|
dc9548 |
+ // ARM64 communicates stack address via sp, but uses a pseudo-sp (PSP) for
|
|
|
dc9548 |
+ // addressing. The register we use for PSP may however also be used by
|
|
|
dc9548 |
+ // calling code, and it is nonvolatile, so save it. Do this as a special
|
|
|
dc9548 |
+ // case first because the generic save/restore code needs the PSP to be
|
|
|
dc9548 |
+ // initialized already.
|
|
|
dc9548 |
+ MOZ_ASSERT(PseudoStackPointer64.Is(masm.GetStackPointer64()));
|
|
|
dc9548 |
+ masm.Str(PseudoStackPointer64, vixl::MemOperand(sp, -16, vixl::PreIndex));
|
|
|
dc9548 |
+
|
|
|
dc9548 |
+ // Initialize the PSP from the SP.
|
|
|
dc9548 |
+ masm.initStackPtr();
|
|
|
dc9548 |
#endif
|
|
|
dc9548 |
|
|
|
dc9548 |
MOZ_ASSERT(propertiesReg.volatile_());
|
|
|
dc9548 |
@@ -239,7 +246,22 @@ static const uintptr_t CLEAR_CONSTRUCTOR_CODE_TOKEN = 0x1;
|
|
|
dc9548 |
if (ScratchDoubleReg.volatile_()) masm.pop(ScratchDoubleReg);
|
|
|
dc9548 |
masm.PopRegsInMask(savedNonVolatileRegisters);
|
|
|
dc9548 |
|
|
|
dc9548 |
- masm.abiret();
|
|
|
dc9548 |
+#ifdef JS_CODEGEN_ARM64
|
|
|
dc9548 |
+ // Now restore the value that was in the PSP register on entry, and return.
|
|
|
dc9548 |
+
|
|
|
dc9548 |
+ // Obtain the correct SP from the PSP.
|
|
|
dc9548 |
+ masm.Mov(sp, PseudoStackPointer64);
|
|
|
dc9548 |
+
|
|
|
dc9548 |
+ // Restore the saved value of the PSP register, this value is whatever the
|
|
|
dc9548 |
+ // caller had saved in it, not any actual SP value, and it must not be
|
|
|
dc9548 |
+ // overwritten subsequently.
|
|
|
dc9548 |
+ masm.Ldr(PseudoStackPointer64, vixl::MemOperand(sp, 16, vixl::PostIndex));
|
|
|
dc9548 |
+
|
|
|
dc9548 |
+ // Perform a plain Ret(), as abiret() will move SP <- PSP and that is wrong.
|
|
|
dc9548 |
+ masm.Ret(vixl::lr);
|
|
|
dc9548 |
+#else
|
|
|
dc9548 |
+ masm.abiret();
|
|
|
dc9548 |
+#endif
|
|
|
dc9548 |
|
|
|
dc9548 |
masm.bind(&failureStoreOther);
|
|
|
dc9548 |
|
|
|
dc9548 |
--
|
|
|
dc9548 |
2.21.0
|
|
|
dc9548 |
|