It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86JITInfo.cpp b/lib/Target/X86/X86JITInfo.cpp
new file mode 100644
index 0000000..b9e5d5b
--- /dev/null
+++ b/lib/Target/X86/X86JITInfo.cpp
@@ -0,0 +1,372 @@
+//===-- X86JITInfo.cpp - Implement the JIT interfaces for the X86 target --===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the JIT interfaces for the X86 target.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "jit"
+#include "X86JITInfo.h"
+#include "X86Relocations.h"
+#include "X86Subtarget.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/Config/alloca.h"
+#include <cstdlib>
+using namespace llvm;
+
+#ifdef _MSC_VER
+ extern "C" void *_AddressOfReturnAddress(void);
+ #pragma intrinsic(_AddressOfReturnAddress)
+#endif
+
+void X86JITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
+ unsigned char *OldByte = (unsigned char *)Old;
+ *OldByte++ = 0xE9; // Emit JMP opcode.
+ unsigned *OldWord = (unsigned *)OldByte;
+ unsigned NewAddr = (intptr_t)New;
+ unsigned OldAddr = (intptr_t)OldWord;
+ *OldWord = NewAddr - OldAddr - 4; // Emit PC-relative addr of New code.
+}
+
+
+/// JITCompilerFunction - This contains the address of the JIT function used to
+/// compile a function lazily.
+static TargetJITInfo::JITCompilerFn JITCompilerFunction;
+
+// Get the ASMPREFIX for the current host. This is often '_'.
+#ifndef __USER_LABEL_PREFIX__
+#define __USER_LABEL_PREFIX__
+#endif
+#define GETASMPREFIX2(X) #X
+#define GETASMPREFIX(X) GETASMPREFIX2(X)
+#define ASMPREFIX GETASMPREFIX(__USER_LABEL_PREFIX__)
+
+// Provide a wrapper for X86CompilationCallback2 that saves non-traditional
+// callee saved registers, for the fastcc calling convention.
+extern "C" {
+#if defined(__x86_64__)
+ // No need to save EAX/EDX for X86-64.
+ void X86CompilationCallback(void);
+ asm(
+ ".text\n"
+ ".align 8\n"
+ ".globl " ASMPREFIX "X86CompilationCallback\n"
+ ASMPREFIX "X86CompilationCallback:\n"
+ // Save RBP
+ "pushq %rbp\n"
+ // Save RSP
+ "movq %rsp, %rbp\n"
+ // Save all int arg registers
+ "pushq %rdi\n"
+ "pushq %rsi\n"
+ "pushq %rdx\n"
+ "pushq %rcx\n"
+ "pushq %r8\n"
+ "pushq %r9\n"
+ // Align stack on 16-byte boundary. ESP might not be properly aligned
+ // (8 byte) if this is called from an indirect stub.
+ "andq $-16, %rsp\n"
+ // Save all XMM arg registers
+ "subq $128, %rsp\n"
+ "movaps %xmm0, (%rsp)\n"
+ "movaps %xmm1, 16(%rsp)\n"
+ "movaps %xmm2, 32(%rsp)\n"
+ "movaps %xmm3, 48(%rsp)\n"
+ "movaps %xmm4, 64(%rsp)\n"
+ "movaps %xmm5, 80(%rsp)\n"
+ "movaps %xmm6, 96(%rsp)\n"
+ "movaps %xmm7, 112(%rsp)\n"
+ // JIT callee
+ "movq %rbp, %rdi\n" // Pass prev frame and return address
+ "movq 8(%rbp), %rsi\n"
+ "call " ASMPREFIX "X86CompilationCallback2\n"
+ // Restore all XMM arg registers
+ "movaps 112(%rsp), %xmm7\n"
+ "movaps 96(%rsp), %xmm6\n"
+ "movaps 80(%rsp), %xmm5\n"
+ "movaps 64(%rsp), %xmm4\n"
+ "movaps 48(%rsp), %xmm3\n"
+ "movaps 32(%rsp), %xmm2\n"
+ "movaps 16(%rsp), %xmm1\n"
+ "movaps (%rsp), %xmm0\n"
+ // Restore RSP
+ "movq %rbp, %rsp\n"
+ // Restore all int arg registers
+ "subq $48, %rsp\n"
+ "popq %r9\n"
+ "popq %r8\n"
+ "popq %rcx\n"
+ "popq %rdx\n"
+ "popq %rsi\n"
+ "popq %rdi\n"
+ // Restore RBP
+ "popq %rbp\n"
+ "ret\n");
+#elif defined(__i386__) || defined(i386) || defined(_M_IX86)
+#ifndef _MSC_VER
+ void X86CompilationCallback(void);
+ asm(
+ ".text\n"
+ ".align 8\n"
+ ".globl " ASMPREFIX "X86CompilationCallback\n"
+ ASMPREFIX "X86CompilationCallback:\n"
+ "pushl %ebp\n"
+ "movl %esp, %ebp\n" // Standard prologue
+ "pushl %eax\n"
+ "pushl %edx\n" // Save EAX/EDX/ECX
+ "pushl %ecx\n"
+#if defined(__APPLE__)
+ "andl $-16, %esp\n" // Align ESP on 16-byte boundary
+#endif
+ "subl $16, %esp\n"
+ "movl 4(%ebp), %eax\n" // Pass prev frame and return address
+ "movl %eax, 4(%esp)\n"
+ "movl %ebp, (%esp)\n"
+ "call " ASMPREFIX "X86CompilationCallback2\n"
+ "movl %ebp, %esp\n" // Restore ESP
+ "subl $12, %esp\n"
+ "popl %ecx\n"
+ "popl %edx\n"
+ "popl %eax\n"
+ "popl %ebp\n"
+ "ret\n");
+
+ // Same as X86CompilationCallback but also saves XMM argument registers.
+ void X86CompilationCallback_SSE(void);
+ asm(
+ ".text\n"
+ ".align 8\n"
+ ".globl " ASMPREFIX "X86CompilationCallback_SSE\n"
+ ASMPREFIX "X86CompilationCallback_SSE:\n"
+ "pushl %ebp\n"
+ "movl %esp, %ebp\n" // Standard prologue
+ "pushl %eax\n"
+ "pushl %edx\n" // Save EAX/EDX/ECX
+ "pushl %ecx\n"
+ "andl $-16, %esp\n" // Align ESP on 16-byte boundary
+ // Save all XMM arg registers
+ "subl $64, %esp\n"
+ "movaps %xmm0, (%esp)\n"
+ "movaps %xmm1, 16(%esp)\n"
+ "movaps %xmm2, 32(%esp)\n"
+ "movaps %xmm3, 48(%esp)\n"
+ "subl $16, %esp\n"
+ "movl 4(%ebp), %eax\n" // Pass prev frame and return address
+ "movl %eax, 4(%esp)\n"
+ "movl %ebp, (%esp)\n"
+ "call " ASMPREFIX "X86CompilationCallback2\n"
+ "addl $16, %esp\n"
+ "movaps 48(%esp), %xmm3\n"
+ "movaps 32(%esp), %xmm2\n"
+ "movaps 16(%esp), %xmm1\n"
+ "movaps (%esp), %xmm0\n"
+ "movl %ebp, %esp\n" // Restore ESP
+ "subl $12, %esp\n"
+ "popl %ecx\n"
+ "popl %edx\n"
+ "popl %eax\n"
+ "popl %ebp\n"
+ "ret\n");
+#else
+ void X86CompilationCallback2(void);
+
+ _declspec(naked) void X86CompilationCallback(void) {
+ __asm {
+ push eax
+ push edx
+ push ecx
+ call X86CompilationCallback2
+ pop ecx
+ pop edx
+ pop eax
+ ret
+ }
+ }
+#endif // _MSC_VER
+
+#else // Not an i386 host
+ void X86CompilationCallback() {
+ assert(0 && "Cannot call X86CompilationCallback() on a non-x86 arch!\n");
+ abort();
+ }
+#endif
+}
+
+/// X86CompilationCallback - This is the target-specific function invoked by the
+/// function stub when we did not know the real target of a call. This function
+/// must locate the start of the stub or call site and pass it into the JIT
+/// compiler function.
+#ifdef _MSC_VER
+extern "C" void X86CompilationCallback2() {
+ assert(sizeof(size_t) == 4); // FIXME: handle Win64
+ intptr_t *RetAddrLoc = (intptr_t *)_AddressOfReturnAddress();
+ RetAddrLoc += 4; // skip over ret addr, edx, eax, ecx
+ intptr_t RetAddr = *RetAddrLoc;
+#else
+extern "C" void X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) {
+ intptr_t *RetAddrLoc = &StackPtr[1];
+#endif
+ assert(*RetAddrLoc == RetAddr &&
+ "Could not find return address on the stack!");
+
+ // It's a stub if there is an interrupt marker after the call.
+ bool isStub = ((unsigned char*)RetAddr)[0] == 0xCD;
+
+ // The call instruction should have pushed the return value onto the stack...
+#ifdef __x86_64__
+ RetAddr--; // Backtrack to the reference itself...
+#else
+ RetAddr -= 4; // Backtrack to the reference itself...
+#endif
+
+#if 0
+ DOUT << "In callback! Addr=" << (void*)RetAddr
+ << " ESP=" << (void*)StackPtr
+ << ": Resolving call to function: "
+ << TheVM->getFunctionReferencedName((void*)RetAddr) << "\n";
+#endif
+
+ // Sanity check to make sure this really is a call instruction.
+#ifdef __x86_64__
+ assert(((unsigned char*)RetAddr)[-2] == 0x41 &&"Not a call instr!");
+ assert(((unsigned char*)RetAddr)[-1] == 0xFF &&"Not a call instr!");
+#else
+ assert(((unsigned char*)RetAddr)[-1] == 0xE8 &&"Not a call instr!");
+#endif
+
+ intptr_t NewVal = (intptr_t)JITCompilerFunction((void*)RetAddr);
+
+ // Rewrite the call target... so that we don't end up here every time we
+ // execute the call.
+#ifdef __x86_64__
+ *(intptr_t *)(RetAddr - 0xa) = NewVal;
+#else
+ *(intptr_t *)RetAddr = (intptr_t)(NewVal-RetAddr-4);
+#endif
+
+ if (isStub) {
+ // If this is a stub, rewrite the call into an unconditional branch
+ // instruction so that two return addresses are not pushed onto the stack
+ // when the requested function finally gets called. This also makes the
+ // 0xCD byte (interrupt) dead, so the marker doesn't effect anything.
+#ifdef __x86_64__
+ ((unsigned char*)RetAddr)[0] = (2 | (4 << 3) | (3 << 6));
+#else
+ ((unsigned char*)RetAddr)[-1] = 0xE9;
+#endif
+ }
+
+ // Change the return address to reexecute the call instruction...
+#ifdef __x86_64__
+ *RetAddrLoc -= 0xd;
+#else
+ *RetAddrLoc -= 5;
+#endif
+}
+
+TargetJITInfo::LazyResolverFn
+X86JITInfo::getLazyResolverFunction(JITCompilerFn F) {
+ JITCompilerFunction = F;
+
+#if (defined(__i386__) || defined(i386) || defined(_M_IX86)) && \
+ !defined(_MSC_VER) && !defined(__x86_64__)
+ unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
+ union {
+ unsigned u[3];
+ char c[12];
+ } text;
+
+ if (!X86::GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1)) {
+ // FIXME: support for AMD family of processors.
+ if (memcmp(text.c, "GenuineIntel", 12) == 0) {
+ X86::GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX);
+ if ((EDX >> 25) & 0x1)
+ return X86CompilationCallback_SSE;
+ }
+ }
+#endif
+
+ return X86CompilationCallback;
+}
+
+void *X86JITInfo::emitFunctionStub(void *Fn, MachineCodeEmitter &MCE) {
+ // Note, we cast to intptr_t here to silence a -pedantic warning that
+ // complains about casting a function pointer to a normal pointer.
+#if (defined(__i386__) || defined(i386) || defined(_M_IX86)) && \
+ !defined(_MSC_VER) && !defined(__x86_64__)
+ bool NotCC = (Fn != (void*)(intptr_t)X86CompilationCallback &&
+ Fn != (void*)(intptr_t)X86CompilationCallback_SSE);
+#else
+ bool NotCC = Fn != (void*)(intptr_t)X86CompilationCallback;
+#endif
+ if (NotCC) {
+#ifdef __x86_64__
+ MCE.startFunctionStub(13, 4);
+ MCE.emitByte(0x49); // REX prefix
+ MCE.emitByte(0xB8+2); // movabsq r10
+ MCE.emitWordLE(((unsigned *)&Fn)[0]);
+ MCE.emitWordLE(((unsigned *)&Fn)[1]);
+ MCE.emitByte(0x41); // REX prefix
+ MCE.emitByte(0xFF); // jmpq *r10
+ MCE.emitByte(2 | (4 << 3) | (3 << 6));
+#else
+ MCE.startFunctionStub(5, 4);
+ MCE.emitByte(0xE9);
+ MCE.emitWordLE((intptr_t)Fn-MCE.getCurrentPCValue()-4);
+#endif
+ return MCE.finishFunctionStub(0);
+ }
+
+#ifdef __x86_64__
+ MCE.startFunctionStub(14, 4);
+ MCE.emitByte(0x49); // REX prefix
+ MCE.emitByte(0xB8+2); // movabsq r10
+ MCE.emitWordLE(((unsigned *)&Fn)[0]);
+ MCE.emitWordLE(((unsigned *)&Fn)[1]);
+ MCE.emitByte(0x41); // REX prefix
+ MCE.emitByte(0xFF); // callq *r10
+ MCE.emitByte(2 | (2 << 3) | (3 << 6));
+#else
+ MCE.startFunctionStub(6, 4);
+ MCE.emitByte(0xE8); // Call with 32 bit pc-rel destination...
+
+ MCE.emitWordLE((intptr_t)Fn-MCE.getCurrentPCValue()-4);
+#endif
+
+ MCE.emitByte(0xCD); // Interrupt - Just a marker identifying the stub!
+ return MCE.finishFunctionStub(0);
+}
+
+/// relocate - Before the JIT can run a block of code that has been emitted,
+/// it must rewrite the code to contain the actual addresses of any
+/// referenced global symbols.
+void X86JITInfo::relocate(void *Function, MachineRelocation *MR,
+ unsigned NumRelocs, unsigned char* GOTBase) {
+ for (unsigned i = 0; i != NumRelocs; ++i, ++MR) {
+ void *RelocPos = (char*)Function + MR->getMachineCodeOffset();
+ intptr_t ResultPtr = (intptr_t)MR->getResultPointer();
+ switch ((X86::RelocationType)MR->getRelocationType()) {
+ case X86::reloc_pcrel_word: {
+ // PC relative relocation, add the relocated value to the value already in
+ // memory, after we adjust it for where the PC is.
+ ResultPtr = ResultPtr-(intptr_t)RelocPos-4-MR->getConstantVal();
+ *((unsigned*)RelocPos) += (unsigned)ResultPtr;
+ break;
+ }
+ case X86::reloc_absolute_word:
+ // Absolute relocation, just add the relocated value to the value already
+ // in memory.
+ *((unsigned*)RelocPos) += (unsigned)ResultPtr;
+ break;
+ case X86::reloc_absolute_dword:
+ *((intptr_t*)RelocPos) += ResultPtr;
+ break;
+ }
+ }
+}