ARMJITInfo.cpp revision 5d392dd93e023f9c14353ea84e2db717792db4bd
1f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman//===-- ARMJITInfo.cpp - Implement the JIT interfaces for the ARM target --===// 2f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// 3f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// The LLVM Compiler Infrastructure 4f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// 5081ce940e7351e90fff829320b7dc6738a6b3815Chris Lattner// This file is distributed under the University of Illinois Open Source 6081ce940e7351e90fff829320b7dc6738a6b3815Chris Lattner// License. See LICENSE.TXT for details. 7f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// 8f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman//===----------------------------------------------------------------------===// 9f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// 10f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// This file implements the JIT interfaces for the ARM target. 11f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// 12f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman//===----------------------------------------------------------------------===// 13f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 14f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman#define DEBUG_TYPE "jit" 15f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman#include "ARMJITInfo.h" 16668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng#include "ARMInstrInfo.h" 175a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng#include "ARMConstantPoolValue.h" 18f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman#include "ARMRelocations.h" 19f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman#include "ARMSubtarget.h" 202b483b5fb10fd3e6223b824726c9403bb47c1e1cNicolas Geoffray#include "llvm/Function.h" 211ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes#include "llvm/CodeGen/JITCodeEmitter.h" 225120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng#include "llvm/Support/Debug.h" 233cb884811f68c27210391441d631146faa74f55eEdwin Török#include "llvm/Support/ErrorHandling.h" 24005975c04c5ffc4ee07107ad60dd7d465464e6f7Daniel Dunbar#include "llvm/Support/raw_ostream.h" 25c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach#include "llvm/System/Memory.h" 26f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman#include <cstdlib> 27f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohmanusing namespace llvm; 28f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 29f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohmanvoid ARMJITInfo::replaceMachineCodeForFunction(void *Old, void *New) { 308316f2d3810dd37bae0f847bc3efd495432b5893Chris Lattner report_fatal_error("ARMJITInfo::replaceMachineCodeForFunction"); 31f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman} 32f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 33f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman/// JITCompilerFunction - This contains the address of the JIT function used to 34f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman/// compile a function lazily. 35f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohmanstatic TargetJITInfo::JITCompilerFn JITCompilerFunction; 36f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 375d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng// Get the ASMPREFIX for the current host. This is often '_'. 385d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng#ifndef __USER_LABEL_PREFIX__ 395d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng#define __USER_LABEL_PREFIX__ 405d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng#endif 415d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng#define GETASMPREFIX2(X) #X 425d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng#define GETASMPREFIX(X) GETASMPREFIX2(X) 435d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng#define ASMPREFIX GETASMPREFIX(__USER_LABEL_PREFIX__) 445d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng 45f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman// CompilationCallback stub - We can't use a C function with inline assembly in 46c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach// it, because we the prolog/epilog inserted by GCC won't work for us (we need 47c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach// to preserve more context and manipulate the stack directly). Instead, 48770d718405114860f3874871848e345873bf7cb4Jim Grosbach// write our own wrapper, which does things our way, so we have complete 49c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach// control over register saving and restoring. 50f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohmanextern "C" { 51f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman#if defined(__arm__) 523dbe9443c80ab668ad5cc8547fdb874634f25818Dan Gohman void ARMCompilationCallback(); 53f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman asm( 54f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman ".text\n" 55f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman ".align 2\n" 565d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng ".globl " ASMPREFIX "ARMCompilationCallback\n" 575d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng ASMPREFIX "ARMCompilationCallback:\n" 58c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // Save caller saved registers since they may contain stuff 59c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // for the real target function right now. We have to act as if this 60c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // whole compilation callback doesn't exist as far as the caller is 61c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // concerned, so we can't just preserve the callee saved regs. 628eab1c8c9852bb78231148ac4fb2d93b975f4ccdJim Grosbach "stmdb sp!, {r0, r1, r2, r3, lr}\n" 6333ddaa3abd51020af9a179e1a683282420098639Xerxes Ranby#if (defined(__VFP_FP__) && !defined(__SOFTFP__)) 64649de51e103995ae3efa6ff4aab7c0a7e480bc56Evan Cheng "fstmfdd sp!, {d0, d1, d2, d3, d4, d5, d6, d7}\n" 65649de51e103995ae3efa6ff4aab7c0a7e480bc56Evan Cheng#endif 66c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // The LR contains the address of the stub function on entry. 67c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // pass it as the argument to the C part of the callback 68c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "mov r0, lr\n" 69c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "sub sp, sp, #4\n" 70c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // Call the C portion of the callback 71c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "bl " ASMPREFIX "ARMCompilationCallbackC\n" 72c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "add sp, sp, #4\n" 73c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // Restoring the LR to the return address of the function that invoked 74c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // the stub and de-allocating the stack space for it requires us to 75c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // swap the two saved LR values on the stack, as they're backwards 76c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // for what we need since the pop instruction has a pre-determined 77c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // order for the registers. 78c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // +--------+ 79c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // 0 | LR | Original return address 80770d718405114860f3874871848e345873bf7cb4Jim Grosbach // +--------+ 81c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // 1 | LR | Stub address (start of stub) 82c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // 2-5 | R3..R0 | Saved registers (we need to preserve all regs) 83649de51e103995ae3efa6ff4aab7c0a7e480bc56Evan Cheng // 6-20 | D0..D7 | Saved VFP registers 84770d718405114860f3874871848e345873bf7cb4Jim Grosbach // +--------+ 85c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // 8633ddaa3abd51020af9a179e1a683282420098639Xerxes Ranby#if (defined(__VFP_FP__) && !defined(__SOFTFP__)) 87649de51e103995ae3efa6ff4aab7c0a7e480bc56Evan Cheng // Restore VFP caller-saved registers. 88649de51e103995ae3efa6ff4aab7c0a7e480bc56Evan Cheng "fldmfdd sp!, {d0, d1, d2, d3, d4, d5, d6, d7}\n" 89649de51e103995ae3efa6ff4aab7c0a7e480bc56Evan Cheng#endif 90649de51e103995ae3efa6ff4aab7c0a7e480bc56Evan Cheng // 91c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // We need to exchange the values in slots 0 and 1 so we can 92c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // return to the address in slot 1 with the address in slot 0 93c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // restored to the LR. 94c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "ldr r0, [sp,#20]\n" 95c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "ldr r1, [sp,#16]\n" 96c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "str r1, [sp,#20]\n" 97c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach "str r0, [sp,#16]\n" 98c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // Return to the (newly modified) stub to invoke the real function. 99c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // The above twiddling of the saved return addresses allows us to 100c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // deallocate everything, including the LR the stub saved, all in one 101c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // pop instruction. 1028eab1c8c9852bb78231148ac4fb2d93b975f4ccdJim Grosbach "ldmia sp!, {r0, r1, r2, r3, lr, pc}\n" 1035d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng ); 1045d582a69ee011cf14e31b5d27b0401db0102ce89Evan Cheng#else // Not an ARM host 105f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman void ARMCompilationCallback() { 106bd448e3ca993226084d7f53445388fcd8e46b996Edwin Török llvm_unreachable("Cannot call ARMCompilationCallback() on a non-ARM arch!"); 107f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman } 108f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman#endif 109f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman} 110f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 111770d718405114860f3874871848e345873bf7cb4Jim Grosbach/// ARMCompilationCallbackC - This is the target-specific function invoked 112770d718405114860f3874871848e345873bf7cb4Jim Grosbach/// by the function stub when we did not know the real target of a call. 113770d718405114860f3874871848e345873bf7cb4Jim Grosbach/// This function must locate the start of the stub or call site and pass 114c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach/// it into the JIT compiler function. 115c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbachextern "C" void ARMCompilationCallbackC(intptr_t StubAddr) { 116c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // Get the address of the compiled code for this function. 117c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach intptr_t NewVal = (intptr_t)JITCompilerFunction((void*)StubAddr); 118f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 119f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman // Rewrite the call target... so that we don't end up here every time we 120c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // execute the call. We're replacing the first two instructions of the 121c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // stub with: 122c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // ldr pc, [pc,#-4] 123c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // <addr> 124886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng if (!sys::Memory::setRangeWritable((void*)StubAddr, 8)) { 125bd448e3ca993226084d7f53445388fcd8e46b996Edwin Török llvm_unreachable("ERROR: Unable to mark stub writable"); 126886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng } 127886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng *(intptr_t *)StubAddr = 0xe51ff004; // ldr pc, [pc, #-4] 128c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach *(intptr_t *)(StubAddr+4) = NewVal; 129886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng if (!sys::Memory::setRangeExecutable((void*)StubAddr, 8)) { 130bd448e3ca993226084d7f53445388fcd8e46b996Edwin Török llvm_unreachable("ERROR: Unable to mark stub executable"); 131886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng } 132f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman} 133f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 134f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan GohmanTargetJITInfo::LazyResolverFn 135f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan GohmanARMJITInfo::getLazyResolverFunction(JITCompilerFn F) { 136f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman JITCompilerFunction = F; 137f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman return ARMCompilationCallback; 138f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman} 139f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 1408af22c446b6eefa8dddd2412c7d779feb4c7bf0aEvan Chengvoid *ARMJITInfo::emitGlobalValueIndirectSym(const GlobalValue *GV, void *Ptr, 1411ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JITCodeEmitter &JCE) { 14243a22289bdf5f2e1d884de469b9ab5b849c077b7Jeffrey Yasskin uint8_t Buffer[4]; 14343a22289bdf5f2e1d884de469b9ab5b849c077b7Jeffrey Yasskin uint8_t *Cur = Buffer; 14443a22289bdf5f2e1d884de469b9ab5b849c077b7Jeffrey Yasskin MachineCodeEmitter::emitWordLEInto(Cur, (intptr_t)Ptr); 14543a22289bdf5f2e1d884de469b9ab5b849c077b7Jeffrey Yasskin void *PtrAddr = JCE.allocIndirectGV( 14643a22289bdf5f2e1d884de469b9ab5b849c077b7Jeffrey Yasskin GV, Buffer, sizeof(Buffer), /*Alignment=*/4); 1475120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng addIndirectSymAddr(Ptr, (intptr_t)PtrAddr); 1485120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng return PtrAddr; 1492d011f9f433116e91c2d98e8f3c32bb9608ce666Evan Cheng} 1502d011f9f433116e91c2d98e8f3c32bb9608ce666Evan Cheng 151f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey YasskinTargetJITInfo::StubLayout ARMJITInfo::getStubLayout() { 152f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin // The stub contains up to 3 4-byte instructions, aligned at 4 bytes, and a 153f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin // 4-byte address. See emitFunctionStub for details. 154f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin StubLayout Result = {16, 4}; 155f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin return Result; 156f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin} 157f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin 1582b483b5fb10fd3e6223b824726c9403bb47c1e1cNicolas Geoffrayvoid *ARMJITInfo::emitFunctionStub(const Function* F, void *Fn, 1591ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JITCodeEmitter &JCE) { 160f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin void *Addr; 161f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman // If this is just a call to an external function, emit a branch instead of a 162f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman // call. The code is the same except for one bit of the last instruction. 163f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman if (Fn != (void*)(intptr_t)ARMCompilationCallback) { 1642d011f9f433116e91c2d98e8f3c32bb9608ce666Evan Cheng // Branch to the corresponding function addr. 1655120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng if (IsPIC) { 166f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin // The stub is 16-byte size and 4-aligned. 1675120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng intptr_t LazyPtr = getIndirectSymAddr(Fn); 1685120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng if (!LazyPtr) { 1695120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng // In PIC mode, the function stub is loading a lazy-ptr. 1701ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes LazyPtr= (intptr_t)emitGlobalValueIndirectSym((GlobalValue*)F, Fn, JCE); 171005975c04c5ffc4ee07107ad60dd7d465464e6f7Daniel Dunbar DEBUG(if (F) 172770d718405114860f3874871848e345873bf7cb4Jim Grosbach errs() << "JIT: Indirect symbol emitted at [" << LazyPtr 173005975c04c5ffc4ee07107ad60dd7d465464e6f7Daniel Dunbar << "] for GV '" << F->getName() << "'\n"; 174005975c04c5ffc4ee07107ad60dd7d465464e6f7Daniel Dunbar else 175005975c04c5ffc4ee07107ad60dd7d465464e6f7Daniel Dunbar errs() << "JIT: Stub emitted at [" << LazyPtr 176005975c04c5ffc4ee07107ad60dd7d465464e6f7Daniel Dunbar << "] for external function at '" << Fn << "'\n"); 1775120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng } 178f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin JCE.emitAlignment(4); 179f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin Addr = (void*)JCE.getCurrentPCValue(); 180f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin if (!sys::Memory::setRangeWritable(Addr, 16)) { 181c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng llvm_unreachable("ERROR: Unable to mark stub writable"); 182c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng } 1830fbd6ad19b836a8138007e82176581755e206c7fEric Christopher JCE.emitWordLE(0xe59fc004); // ldr ip, [pc, #+4] 1841ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE(0xe08fc00c); // L_func$scv: add ip, pc, ip 1851ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE(0xe59cf000); // ldr pc, [ip] 186f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin JCE.emitWordLE(LazyPtr - (intptr_t(Addr)+4+8)); // func - (L_func$scv+8) 187f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin sys::Memory::InvalidateInstructionCache(Addr, 16); 188f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin if (!sys::Memory::setRangeExecutable(Addr, 16)) { 189c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng llvm_unreachable("ERROR: Unable to mark stub executable"); 190c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng } 1915120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng } else { 1925120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng // The stub is 8-byte size and 4-aligned. 193f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin JCE.emitAlignment(4); 194f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin Addr = (void*)JCE.getCurrentPCValue(); 195f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin if (!sys::Memory::setRangeWritable(Addr, 8)) { 196c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng llvm_unreachable("ERROR: Unable to mark stub writable"); 197c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng } 1981ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE(0xe51ff004); // ldr pc, [pc, #-4] 1991ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE((intptr_t)Fn); // addr of function 200f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin sys::Memory::InvalidateInstructionCache(Addr, 8); 201f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin if (!sys::Memory::setRangeExecutable(Addr, 8)) { 202c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng llvm_unreachable("ERROR: Unable to mark stub executable"); 203c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng } 2045120b9fa2d6559eb94dab3079ff346926c73940fEvan Cheng } 205f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman } else { 206c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // The compilation callback will overwrite the first two words of this 207770d718405114860f3874871848e345873bf7cb4Jim Grosbach // stub with indirect branch instructions targeting the compiled code. 208c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // This stub sets the return address to restart the stub, so that 209c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // the new branch will be invoked when we come back. 210c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // 2112d011f9f433116e91c2d98e8f3c32bb9608ce666Evan Cheng // Branch and link to the compilation callback. 2122d011f9f433116e91c2d98e8f3c32bb9608ce666Evan Cheng // The stub is 16-byte size and 4-byte aligned. 213f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin JCE.emitAlignment(4); 214f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin Addr = (void*)JCE.getCurrentPCValue(); 215f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin if (!sys::Memory::setRangeWritable(Addr, 16)) { 216c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng llvm_unreachable("ERROR: Unable to mark stub writable"); 217c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng } 218c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // Save LR so the callback can determine which stub called it. 219c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // The compilation callback is responsible for popping this prior 220c599a35bba7259e9b71aad881f5fc877ee34dc3dJim Grosbach // to returning. 2211ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE(0xe92d4000); // push {lr} 222886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng // Set the return address to go back to the start of this stub. 2231ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE(0xe24fe00c); // sub lr, pc, #12 224886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng // Invoke the compilation callback. 2251ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE(0xe51ff004); // ldr pc, [pc, #-4] 226886dafe6e0958d8da971a539954ae4c050c783daEvan Cheng // The address of the compilation callback. 2271ea31ff434f7966f3d8b2c158b4f20950e94e80dBruno Cardoso Lopes JCE.emitWordLE((intptr_t)ARMCompilationCallback); 228f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin sys::Memory::InvalidateInstructionCache(Addr, 16); 229f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin if (!sys::Memory::setRangeExecutable(Addr, 16)) { 230c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng llvm_unreachable("ERROR: Unable to mark stub executable"); 231c84d4d3a2e752a4ba621587c066c1177cb8d5f40Evan Cheng } 232f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman } 233f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 234f8f9acf65f39634e24604568f1cab3cca14ff18bJeffrey Yasskin return Addr; 235f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman} 236f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman 2370f63ae111d5a509911fc61246c1acc62f8c58f18Evan Chengintptr_t ARMJITInfo::resolveRelocDestAddr(MachineRelocation *MR) const { 2385a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng ARM::RelocationType RT = (ARM::RelocationType)MR->getRelocationType(); 239668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng switch (RT) { 240668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng default: 241668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng return (intptr_t)(MR->getResultPointer()); 242668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng case ARM::reloc_arm_pic_jt: 243260ae19f81f574a4ec2c4cc648a63bd4278e4615Evan Cheng // Destination address - jump table base. 244260ae19f81f574a4ec2c4cc648a63bd4278e4615Evan Cheng return (intptr_t)(MR->getResultPointer()) - MR->getConstantVal(); 245668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng case ARM::reloc_arm_jt_base: 246260ae19f81f574a4ec2c4cc648a63bd4278e4615Evan Cheng // Jump table base address. 2470f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng return getJumpTableBaseAddr(MR->getJumpTableIndex()); 248668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng case ARM::reloc_arm_cp_entry: 249668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng case ARM::reloc_arm_vfp_cp_entry: 250260ae19f81f574a4ec2c4cc648a63bd4278e4615Evan Cheng // Constant pool entry address. 2515a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng return getConstantPoolEntryAddr(MR->getConstantPoolIndex()); 252668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng case ARM::reloc_arm_machine_cp_entry: { 2538600421afe774e20c147d9505e3ddc0c1fc04a99Evan Cheng ARMConstantPoolValue *ACPV = (ARMConstantPoolValue*)MR->getConstantVal(); 2545a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng assert((!ACPV->hasModifier() && !ACPV->mustAddCurrentAddress()) && 2555a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng "Can't handle this machine constant pool entry yet!"); 2565a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng intptr_t Addr = (intptr_t)(MR->getResultPointer()); 2575a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng Addr -= getPCLabelAddr(ACPV->getLabelId()) + ACPV->getPCAdjustment(); 2585a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng return Addr; 2595a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng } 260668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng } 2615a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng} 2625a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng 263f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman/// relocate - Before the JIT can run a block of code that has been emitted, 264f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman/// it must rewrite the code to contain the actual addresses of any 265f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman/// referenced global symbols. 266f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohmanvoid ARMJITInfo::relocate(void *Function, MachineRelocation *MR, 267f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman unsigned NumRelocs, unsigned char* GOTBase) { 268a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng for (unsigned i = 0; i != NumRelocs; ++i, ++MR) { 269a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng void *RelocPos = (char*)Function + MR->getMachineCodeOffset(); 2700f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng intptr_t ResultPtr = resolveRelocDestAddr(MR); 271a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng switch ((ARM::RelocationType)MR->getRelocationType()) { 272f07a9b69d1c91187d73667b46aa423d4325ccf04Evan Cheng case ARM::reloc_arm_cp_entry: 273668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng case ARM::reloc_arm_vfp_cp_entry: 274a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng case ARM::reloc_arm_relative: { 27572551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // It is necessary to calculate the correct PC relative value. We 27672551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // subtract the base addr from the target addr to form a byte offset. 277668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng ResultPtr = ResultPtr - (intptr_t)RelocPos - 8; 27872551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // If the result is positive, set bit U(23) to 1. 27972551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster if (ResultPtr >= 0) 280668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng *((intptr_t*)RelocPos) |= 1 << ARMII::U_BitShift; 28172551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster else { 282668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng // Otherwise, obtain the absolute value and set bit U(23) to 0. 283ba3d8bcb52d332b1af1283585e0d01d636bc2899Evan Cheng *((intptr_t*)RelocPos) &= ~(1 << ARMII::U_BitShift); 284668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng ResultPtr = - ResultPtr; 28572551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster } 2865a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng // Set the immed value calculated. 287668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng // VFP immediate offset is multiplied by 4. 288668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng if (MR->getRelocationType() == ARM::reloc_arm_vfp_cp_entry) 289668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng ResultPtr = ResultPtr >> 2; 290668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng *((intptr_t*)RelocPos) |= ResultPtr; 2915a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng // Set register Rn to PC. 292668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng *((intptr_t*)RelocPos) |= 293668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng ARMRegisterInfo::getRegisterNumbering(ARM::PC) << ARMII::RegRnShift; 294a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng break; 295a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng } 296260ae19f81f574a4ec2c4cc648a63bd4278e4615Evan Cheng case ARM::reloc_arm_pic_jt: 2975a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng case ARM::reloc_arm_machine_cp_entry: 298f07a9b69d1c91187d73667b46aa423d4325ccf04Evan Cheng case ARM::reloc_arm_absolute: { 2995a033a6c9c08d06f316e42b111cc79756c672733Evan Cheng // These addresses have already been resolved. 300668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng *((intptr_t*)RelocPos) |= (intptr_t)ResultPtr; 301f07a9b69d1c91187d73667b46aa423d4325ccf04Evan Cheng break; 302f07a9b69d1c91187d73667b46aa423d4325ccf04Evan Cheng } 303a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng case ARM::reloc_arm_branch: { 30472551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // It is necessary to calculate the correct value of signed_immed_24 30572551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // field. We subtract the base addr from the target addr to form a 30672551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // byte offset, which must be inside the range -33554432 and +33554428. 30772551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // Then, we set the signed_immed_24 field of the instruction to bits 30872551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster // [25:2] of the byte offset. More details ARM-ARM p. A4-11. 3090f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng ResultPtr = ResultPtr - (intptr_t)RelocPos - 8; 31072551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster ResultPtr = (ResultPtr & 0x03FFFFFC) >> 2; 31172551daeaad642f5bb9318d269bc0b7834381ef4Raul Herbster assert(ResultPtr >= -33554432 && ResultPtr <= 33554428); 312668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng *((intptr_t*)RelocPos) |= ResultPtr; 313a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng break; 314a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng } 3150f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng case ARM::reloc_arm_jt_base: { 3160f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng // JT base - (instruction addr + 8) 3170f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng ResultPtr = ResultPtr - (intptr_t)RelocPos - 8; 318668d0df68e2c40e4f4073535afcc5ec210d7d200Evan Cheng *((intptr_t*)RelocPos) |= ResultPtr; 3190f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng break; 3200f63ae111d5a509911fc61246c1acc62f8c58f18Evan Cheng } 3215d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang case ARM::reloc_arm_movw: { 3225d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang ResultPtr = ResultPtr & 0xFFFF; 3235d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang *((intptr_t*)RelocPos) |= ResultPtr & 0xFFF; 3245d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang *((intptr_t*)RelocPos) |= ((ResultPtr >> 12) & 0xF) << 16; 3255d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang break; 3265d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang } 3275d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang case ARM::reloc_arm_movt: { 3285d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang ResultPtr = (ResultPtr >> 16) & 0xFFFF; 3295d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang *((intptr_t*)RelocPos) |= ResultPtr & 0xFFF; 3305d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang *((intptr_t*)RelocPos) |= ((ResultPtr >> 12) & 0xF) << 16; 3315d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang break; 3325d392dd93e023f9c14353ea84e2db717792db4bdZonr Chang } 333a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng } 334a7b3e7c33f1ef7be844fde18dcd9e24afdc97748Evan Cheng } 335f17a25c88b892d30c2b41ba7ecdfbdfb2b4be9cDan Gohman} 336