2 files changed, 94 insertions, 0 deletions

diff --git a/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc b/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc
index 3a73ae09f8..edd1a977e6 100644
--- a/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc
+++ b/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc
@@ -18,6 +18,30 @@
 namespace v8 {
 namespace internal {
 
+void SharedTurboAssembler::Move(Register dst, Register src) {
+  // Helper to paper over the different assembler function names.
+  if (dst != src) {
+#if V8_TARGET_ARCH_IA32
+    mov(dst, src);
+#elif V8_TARGET_ARCH_X64
+    movq(dst, src);
+#else
+#error Unsupported target architecture.
+#endif
+  }
+}
+
+void SharedTurboAssembler::And(Register dst, Immediate src) {
+  // Helper to paper over the different assembler function names.
+#if V8_TARGET_ARCH_IA32
+  and_(dst, src);
+#elif V8_TARGET_ARCH_X64
+  andq(dst, src);
+#else
+#error Unsupported target architecture.
+#endif
+}
+
 void SharedTurboAssembler::Movapd(XMMRegister dst, XMMRegister src) {
   if (CpuFeatures::IsSupported(AVX)) {
     CpuFeatureScope avx_scope(this, AVX);
@@ -496,6 +520,67 @@ void SharedTurboAssembler::I64x2GeS(XMMRegister dst, XMMRegister src0,
   }
 }
 
+void SharedTurboAssembler::I64x2ShrS(XMMRegister dst, XMMRegister src,
+                                     uint8_t shift, XMMRegister xmm_tmp) {
+  DCHECK_GT(64, shift);
+  DCHECK_NE(xmm_tmp, dst);
+  DCHECK_NE(xmm_tmp, src);
+  // Use logical right shift to emulate arithmetic right shifts:
+  // Given:
+  // signed >> c
+  //   == (signed + 2^63 - 2^63) >> c
+  //   == ((signed + 2^63) >> c) - (2^63 >> c)
+  //                                ^^^^^^^^^
+  //                                 xmm_tmp
+  // signed + 2^63 is an unsigned number, so we can use logical right shifts.
+
+  // xmm_tmp = wasm_i64x2_const(0x80000000'00000000).
+  Pcmpeqd(xmm_tmp, xmm_tmp);
+  Psllq(xmm_tmp, byte{63});
+
+  if (!CpuFeatures::IsSupported(AVX) && (dst != src)) {
+    Movapd(dst, src);
+    src = dst;
+  }
+  // Add a bias of 2^63 to convert signed to unsigned.
+  // Since only highest bit changes, use pxor instead of paddq.
+  Pxor(dst, src, xmm_tmp);
+  // Logically shift both value and bias.
+  Psrlq(dst, shift);
+  Psrlq(xmm_tmp, shift);
+  // Subtract shifted bias to convert back to signed value.
+  Psubq(dst, xmm_tmp);
+}
+
+void SharedTurboAssembler::I64x2ShrS(XMMRegister dst, XMMRegister src,
+                                     Register shift, XMMRegister xmm_tmp,
+                                     XMMRegister xmm_shift,
+                                     Register tmp_shift) {
+  DCHECK_NE(xmm_tmp, dst);
+  DCHECK_NE(xmm_tmp, src);
+  DCHECK_NE(xmm_shift, dst);
+  DCHECK_NE(xmm_shift, src);
+  // tmp_shift can alias shift since we don't use shift after masking it.
+
+  // See I64x2ShrS with constant shift for explanation of this algorithm.
+  Pcmpeqd(xmm_tmp, xmm_tmp);
+  Psllq(xmm_tmp, byte{63});
+
+  // Shift modulo 64.
+  Move(tmp_shift, shift);
+  And(tmp_shift, Immediate(0x3F));
+  Movd(xmm_shift, tmp_shift);
+
+  if (!CpuFeatures::IsSupported(AVX) && (dst != src)) {
+    Movapd(dst, src);
+    src = dst;
+  }
+  Pxor(dst, src, xmm_tmp);
+  Psrlq(dst, xmm_shift);
+  Psrlq(xmm_tmp, xmm_shift);
+  Psubq(dst, xmm_tmp);
+}
+
 // 1. Unpack src0, src1 into even-number elements of scratch.
 // 2. Unpack src1, src0 into even-number elements of dst.
 // 3. Multiply 1. with 2.
diff --git a/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h b/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h
index add62a5a49..7c6f7185b9 100644
--- a/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h
+++ b/deps/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h
@@ -33,6 +33,10 @@ class V8_EXPORT_PRIVATE SharedTurboAssembler : public TurboAssemblerBase {
  public:
   using TurboAssemblerBase::TurboAssemblerBase;
 
+  // Move if registers are not identical.
+  void Move(Register dst, Register src);
+  void And(Register dst, Immediate src);
+
   void Movapd(XMMRegister dst, XMMRegister src);
 
   template <typename Dst, typename Src>
@@ -315,6 +319,11 @@ class V8_EXPORT_PRIVATE SharedTurboAssembler : public TurboAssemblerBase {
                 XMMRegister scratch);
   void I64x2GeS(XMMRegister dst, XMMRegister src0, XMMRegister src1,
                 XMMRegister scratch);
+  void I64x2ShrS(XMMRegister dst, XMMRegister src, uint8_t shift,
+                 XMMRegister xmm_tmp);
+  void I64x2ShrS(XMMRegister dst, XMMRegister src, Register shift,
+                 XMMRegister xmm_tmp, XMMRegister xmm_shift,
+                 Register tmp_shift);
   void I64x2ExtMul(XMMRegister dst, XMMRegister src1, XMMRegister src2,
                    XMMRegister scratch, bool low, bool is_signed);
   void I64x2SConvertI32x4High(XMMRegister dst, XMMRegister src);