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1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 //     * Redistributions of source code must retain the above copyright
7 //       notice, this list of conditions and the following disclaimer.
8 //     * Redistributions in binary form must reproduce the above
9 //       copyright notice, this list of conditions and the following
10 //       disclaimer in the documentation and/or other materials provided
11 //       with the distribution.
12 //     * Neither the name of Google Inc. nor the names of its
13 //       contributors may be used to endorse or promote products derived
14 //       from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 
28 #include "v8.h"
29 
30 #if defined(V8_TARGET_ARCH_X64)
31 
32 #include "codegen.h"
33 
34 namespace v8 {
35 namespace internal {
36 
37 // -------------------------------------------------------------------------
38 // Platform-specific RuntimeCallHelper functions.
39 
BeforeCall(MacroAssembler * masm) const40 void StubRuntimeCallHelper::BeforeCall(MacroAssembler* masm) const {
41   masm->EnterInternalFrame();
42 }
43 
44 
AfterCall(MacroAssembler * masm) const45 void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
46   masm->LeaveInternalFrame();
47 }
48 
49 
50 #define __ masm.
51 
52 #ifdef _WIN64
53 typedef double (*ModuloFunction)(double, double);
54 // Define custom fmod implementation.
CreateModuloFunction()55 ModuloFunction CreateModuloFunction() {
56   size_t actual_size;
57   byte* buffer = static_cast<byte*>(OS::Allocate(Assembler::kMinimalBufferSize,
58                                                  &actual_size,
59                                                  true));
60   CHECK(buffer);
61   Assembler masm(NULL, buffer, static_cast<int>(actual_size));
62   // Generated code is put into a fixed, unmovable, buffer, and not into
63   // the V8 heap. We can't, and don't, refer to any relocatable addresses
64   // (e.g. the JavaScript nan-object).
65 
66   // Windows 64 ABI passes double arguments in xmm0, xmm1 and
67   // returns result in xmm0.
68   // Argument backing space is allocated on the stack above
69   // the return address.
70 
71   // Compute x mod y.
72   // Load y and x (use argument backing store as temporary storage).
73   __ movsd(Operand(rsp, kPointerSize * 2), xmm1);
74   __ movsd(Operand(rsp, kPointerSize), xmm0);
75   __ fld_d(Operand(rsp, kPointerSize * 2));
76   __ fld_d(Operand(rsp, kPointerSize));
77 
78   // Clear exception flags before operation.
79   {
80     Label no_exceptions;
81     __ fwait();
82     __ fnstsw_ax();
83     // Clear if Illegal Operand or Zero Division exceptions are set.
84     __ testb(rax, Immediate(5));
85     __ j(zero, &no_exceptions);
86     __ fnclex();
87     __ bind(&no_exceptions);
88   }
89 
90   // Compute st(0) % st(1)
91   {
92     Label partial_remainder_loop;
93     __ bind(&partial_remainder_loop);
94     __ fprem();
95     __ fwait();
96     __ fnstsw_ax();
97     __ testl(rax, Immediate(0x400 /* C2 */));
98     // If C2 is set, computation only has partial result. Loop to
99     // continue computation.
100     __ j(not_zero, &partial_remainder_loop);
101   }
102 
103   Label valid_result;
104   Label return_result;
105   // If Invalid Operand or Zero Division exceptions are set,
106   // return NaN.
107   __ testb(rax, Immediate(5));
108   __ j(zero, &valid_result);
109   __ fstp(0);  // Drop result in st(0).
110   int64_t kNaNValue = V8_INT64_C(0x7ff8000000000000);
111   __ movq(rcx, kNaNValue, RelocInfo::NONE);
112   __ movq(Operand(rsp, kPointerSize), rcx);
113   __ movsd(xmm0, Operand(rsp, kPointerSize));
114   __ jmp(&return_result);
115 
116   // If result is valid, return that.
117   __ bind(&valid_result);
118   __ fstp_d(Operand(rsp, kPointerSize));
119   __ movsd(xmm0, Operand(rsp, kPointerSize));
120 
121   // Clean up FPU stack and exceptions and return xmm0
122   __ bind(&return_result);
123   __ fstp(0);  // Unload y.
124 
125   Label clear_exceptions;
126   __ testb(rax, Immediate(0x3f /* Any Exception*/));
127   __ j(not_zero, &clear_exceptions);
128   __ ret(0);
129   __ bind(&clear_exceptions);
130   __ fnclex();
131   __ ret(0);
132 
133   CodeDesc desc;
134   masm.GetCode(&desc);
135   // Call the function from C++ through this pointer.
136   return FUNCTION_CAST<ModuloFunction>(buffer);
137 }
138 
139 #endif
140 
141 
142 #undef __
143 
144 } }  // namespace v8::internal
145 
146 #endif  // V8_TARGET_ARCH_X64
147