[llvm] r234138 - [Orc] Tidy up the assembly for the x86-64 resolver block.
Lang Hames
lhames at gmail.com
Sun Apr 5 20:01:30 PDT 2015
Author: lhames
Date: Sun Apr 5 22:01:29 2015
New Revision: 234138
URL: http://llvm.org/viewvc/llvm-project?rev=234138&view=rev
Log:
[Orc] Tidy up the assembly for the x86-64 resolver block.
Modified:
llvm/trunk/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp
Modified: llvm/trunk/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp?rev=234138&r1=234137&r2=234138&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp (original)
+++ llvm/trunk/lib/ExecutionEngine/Orc/OrcTargetSupport.cpp Sun Apr 5 22:01:29 2015
@@ -6,39 +6,6 @@ using namespace llvm::orc;
namespace {
-std::array<const char *, 12> X86GPRsToSave = {{
- "rbp", "rbx", "r12", "r13", "r14", "r15", // Callee saved.
- "rdi", "rsi", "rdx", "rcx", "r8", "r9", // Int args.
-}};
-
-std::array<const char *, 8> X86XMMsToSave = {{
- "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7" // FP args
-}};
-
-template <typename OStream> unsigned saveX86Regs(OStream &OS) {
- for (const auto &GPR : X86GPRsToSave)
- OS << " pushq %" << GPR << "\n";
-
- OS << " subq $" << (16 * X86XMMsToSave.size()) << ", %rsp\n";
-
- for (unsigned i = 0; i < X86XMMsToSave.size(); ++i)
- OS << " movdqu %" << X86XMMsToSave[i] << ", "
- << (16 * (X86XMMsToSave.size() - i - 1)) << "(%rsp)\n";
-
- return (8 * X86GPRsToSave.size()) + (16 * X86XMMsToSave.size());
-}
-
-template <typename OStream> void restoreX86Regs(OStream &OS) {
- for (unsigned i = 0; i < X86XMMsToSave.size(); ++i)
- OS << " movdqu " << (16 * i) << "(%rsp), %"
- << X86XMMsToSave[(X86XMMsToSave.size() - i - 1)] << "\n";
- OS << " addq $" << (16 * X86XMMsToSave.size()) << ", %rsp\n";
-
- for (unsigned i = 0; i < X86GPRsToSave.size(); ++i)
- OS << " popq %" << X86GPRsToSave[X86GPRsToSave.size() - i - 1] << "\n";
-}
-
-template <typename TargetT>
uint64_t executeCompileCallback(JITCompileCallbackManagerBase *JCBM,
TargetAddress CallbackID) {
return JCBM->executeCompileCallback(CallbackID);
@@ -53,14 +20,26 @@ const char* OrcX86_64::ResolverBlockName
void OrcX86_64::insertResolverBlock(
Module &M, JITCompileCallbackManagerBase &JCBM) {
+
+ // Trampoline code-sequence length, used to get trampoline address from return
+ // address.
const unsigned X86_64_TrampolineLength = 6;
- auto CallbackPtr = executeCompileCallback<OrcX86_64>;
+
+ // List of x86-64 GPRs to save.
+ std::array<const char *, 11> GPRs = {{
+ "rbx", "r12", "r13", "r14", "r15", // Callee saved (rbp preserved below).
+ "rdi", "rsi", "rdx", "rcx", "r8", "r9", // Int args.
+ }};
+
+ // Address of the executeCompileCallback function.
uint64_t CallbackAddr =
- static_cast<uint64_t>(reinterpret_cast<uintptr_t>(CallbackPtr));
+ static_cast<uint64_t>(
+ reinterpret_cast<uintptr_t>(executeCompileCallback));
std::ostringstream AsmStream;
Triple TT(M.getTargetTriple());
+ // Switch to text section.
if (TT.getOS() == Triple::Darwin)
AsmStream << ".section __TEXT,__text,regular,pure_instructions\n"
<< ".align 4, 0x90\n";
@@ -68,24 +47,46 @@ void OrcX86_64::insertResolverBlock(
AsmStream << ".text\n"
<< ".align 16, 0x90\n";
+ // Bake in a pointer to the callback manager immediately before the
+ // start of the resolver function.
AsmStream << "jit_callback_manager_addr:\n"
- << " .quad " << &JCBM << "\n"
- << ResolverBlockName << ":\n";
+ << " .quad " << &JCBM << "\n";
- uint64_t ReturnAddrOffset = saveX86Regs(AsmStream);
+ // Start the resolver function.
+ AsmStream << ResolverBlockName << ":\n"
+ << " pushq %rbp\n"
+ << " movq %rsp, %rbp\n";
+
+ // Store the GPRs.
+ for (const auto &GPR : GPRs)
+ AsmStream << " pushq %" << GPR << "\n";
+
+ // Store floating-point state with FXSAVE.
+ AsmStream << " subq $512, %rsp\n"
+ << " fxsave (%rsp)\n"
- // Compute index, load object address, and call JIT.
- AsmStream << " leaq jit_callback_manager_addr(%rip), %rdi\n"
+ // Load callback manager address, compute trampoline address, call JIT.
+ << " lea jit_callback_manager_addr(%rip), %rdi\n"
<< " movq (%rdi), %rdi\n"
- << " movq " << ReturnAddrOffset << "(%rsp), %rsi\n"
+ << " movq 0x8(%rbp), %rsi\n"
<< " subq $" << X86_64_TrampolineLength << ", %rsi\n"
<< " movabsq $" << CallbackAddr << ", %rax\n"
<< " callq *%rax\n"
- << " movq %rax, " << ReturnAddrOffset << "(%rsp)\n";
-
- restoreX86Regs(AsmStream);
- AsmStream << " retq\n";
+ // Replace the return to the trampoline with the return address of the
+ // compiled function body.
+ << " movq %rax, 0x8(%rbp)\n"
+
+ // Restore the floating point state.
+ << " fxrstor (%rsp)\n"
+ << " addq $512, %rsp\n";
+
+ for (const auto &GPR : make_range(GPRs.rbegin(), GPRs.rend()))
+ AsmStream << " popq %" << GPR << "\n";
+
+ // Restore original RBP and return to compiled function body.
+ AsmStream << " popq %rbp\n"
+ << " retq\n";
M.appendModuleInlineAsm(AsmStream.str());
}
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