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mail/thunderbird/files/patch-bug1375074
- This file was added.
| commit fc25eb4380d0 | |||||
| Author: Lars T Hansen <lhansen@mozilla.com> | |||||
| Date: Wed Feb 28 13:57:52 2018 +0100 | |||||
| Bug 1375074 - Save and restore non-volatile x28 on ARM64 for generated unboxed object constructor. r=sstangl | |||||
| --HG-- | |||||
| extra : rebase_source : 4a2824b23cf7453d07c962123f780c0ff2fd5292 | |||||
| extra : source : dec6ab6522a4eb4b3c2defc5078b38ed904f3383 | |||||
| --- | |||||
| js/src/jit-test/tests/bug1375074.js | 18 ++++++++++++++++++ | |||||
| js/src/vm/UnboxedObject.cpp | 25 ++++++++++++++++++++++++- | |||||
| 2 files changed, 42 insertions(+), 1 deletion(-) | |||||
| diff --git js/src/jit-test/tests/bug1375074.js js/src/jit-test/tests/bug1375074.js | |||||
| new file mode 100644 | |||||
| index 0000000000000..8bf01d96903fc | |||||
| --- /dev/null | |||||
| +++ mozilla/js/src/jit-test/tests/bug1375074.js | |||||
| @@ -0,0 +1,18 @@ | |||||
| +// This forces the VM to start creating unboxed objects and thus stresses a | |||||
| +// particular path into generated code for a specialized unboxed object | |||||
| +// constructor. | |||||
| + | |||||
| +var K = 2000; // 2000 should be plenty | |||||
| +var s = "["; | |||||
| +var i; | |||||
| +for ( i=0; i < K-1; i++ ) | |||||
| + s = s + `{"i":${i}},`; | |||||
| +s += `{"i":${i}}]`; | |||||
| +var v = JSON.parse(s); | |||||
| + | |||||
| +assertEq(v.length == K, true); | |||||
| + | |||||
| +for ( i=0; i < K; i++) { | |||||
| + assertEq(v[i] instanceof Object, true); | |||||
| + assertEq(v[i].i, i); | |||||
| +} | |||||
| diff --git js/src/vm/UnboxedObject.cpp js/src/vm/UnboxedObject.cpp | |||||
| index c8c178965c488..5badf328ede4f 100644 | |||||
| --- mozilla/js/src/vm/UnboxedObject.cpp | |||||
| +++ mozilla/js/src/vm/UnboxedObject.cpp | |||||
| @@ -95,7 +95,15 @@ UnboxedLayout::makeConstructorCode(JSContext* cx, HandleObjectGroup group) | |||||
| #endif | |||||
| #ifdef JS_CODEGEN_ARM64 | |||||
| - // ARM64 communicates stack address via sp, but uses a pseudo-sp for addressing. | |||||
| + // ARM64 communicates stack address via sp, but uses a pseudo-sp (PSP) for | |||||
| + // addressing. The register we use for PSP may however also be used by | |||||
| + // calling code, and it is nonvolatile, so save it. Do this as a special | |||||
| + // case first because the generic save/restore code needs the PSP to be | |||||
| + // initialized already. | |||||
| + MOZ_ASSERT(PseudoStackPointer64.Is(masm.GetStackPointer64())); | |||||
| + masm.Str(PseudoStackPointer64, vixl::MemOperand(sp, -16, vixl::PreIndex)); | |||||
| + | |||||
| + // Initialize the PSP from the SP. | |||||
| masm.initStackPtr(); | |||||
| #endif | |||||
| @@ -233,7 +241,22 @@ UnboxedLayout::makeConstructorCode(JSContext* cx, HandleObjectGroup group) | |||||
| masm.pop(ScratchDoubleReg); | |||||
| masm.PopRegsInMask(savedNonVolatileRegisters); | |||||
| +#ifdef JS_CODEGEN_ARM64 | |||||
| + // Now restore the value that was in the PSP register on entry, and return. | |||||
| + | |||||
| + // Obtain the correct SP from the PSP. | |||||
| + masm.Mov(sp, PseudoStackPointer64); | |||||
| + | |||||
| + // Restore the saved value of the PSP register, this value is whatever the | |||||
| + // caller had saved in it, not any actual SP value, and it must not be | |||||
| + // overwritten subsequently. | |||||
| + masm.Ldr(PseudoStackPointer64, vixl::MemOperand(sp, 16, vixl::PostIndex)); | |||||
| + | |||||
| + // Perform a plain Ret(), as abiret() will move SP <- PSP and that is wrong. | |||||
| + masm.Ret(vixl::lr); | |||||
| +#else | |||||
| masm.abiret(); | |||||
| +#endif | |||||
| masm.bind(&failureStoreOther); | |||||