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/ARM/ARMJITInfo.cpp b/lib/Target/ARM/ARMJITInfo.cpp
new file mode 100644
index 0000000..294a12b
--- /dev/null
+++ b/lib/Target/ARM/ARMJITInfo.cpp
@@ -0,0 +1,131 @@
+//===-- ARMJITInfo.cpp - Implement the JIT interfaces for the ARM target --===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the Raul Herbster and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the JIT interfaces for the ARM target.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "jit"
+#include "ARMJITInfo.h"
+#include "ARMRelocations.h"
+#include "ARMSubtarget.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/Config/alloca.h"
+#include <cstdlib>
+using namespace llvm;
+
+void ARMJITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
+ unsigned char *OldByte = (unsigned char *)Old;
+ *OldByte++ = 0xEA; // Emit B 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;
+
+// CompilationCallback stub - We can't use a C function with inline assembly in
+// it, because we the prolog/epilog inserted by GCC won't work for us. Instead,
+// write our own wrapper, which does things our way, so we have complete control
+// over register saving and restoring.
+extern "C" {
+#if defined(__arm__)
+ void ARMCompilationCallback(void);
+ asm(
+ ".text\n"
+ ".align 2\n"
+ ".globl ARMCompilationCallback\n"
+ "ARMCompilationCallback:\n"
+ // save main registers
+ "mov ip, sp\n"
+ "stmfd sp!, {fp, ip, lr, pc}\n"
+ "sub fp, ip, #4\n"
+ // arguments to Compilation Callback
+ // r0 - our lr (address of the call instruction in stub plus 4)
+ // r1 - stub's lr (address of instruction that called the stub plus 4)
+ "mov r0, fp\n" // stub's frame
+ "mov r1, lr\n" // stub's lr
+ "bl ARMCompilationCallbackC\n"
+ // restore main registers
+ "ldmfd sp, {fp, sp, pc}\n");
+#else // Not an ARM host
+ void ARMCompilationCallback() {
+ assert(0 && "Cannot call ARMCompilationCallback() on a non-ARM arch!\n");
+ abort();
+ }
+#endif
+}
+
+/// ARMCompilationCallbackC - 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.
+extern "C" void ARMCompilationCallbackC(intptr_t *StackPtr, intptr_t RetAddr) {
+ intptr_t *RetAddrLoc = &StackPtr[-1];
+
+ assert(*RetAddrLoc == RetAddr &&
+ "Could not find return address on the stack!");
+#if 0
+ DOUT << "In callback! Addr=" << (void*)RetAddr
+ << " FP=" << (void*)StackPtr
+ << ": Resolving call to function: "
+ << TheVM->getFunctionReferencedName((void*)RetAddr) << "\n";
+#endif
+
+ // Sanity check to make sure this really is a branch and link instruction.
+ assert(((unsigned char*)RetAddr-1)[3] == 0xEB && "Not a branch and link instr!");
+
+ 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.
+ *(intptr_t *)RetAddr = (intptr_t)(NewVal-RetAddr-4);
+
+ // Change the return address to reexecute the branch and link instruction...
+ *RetAddrLoc -= 1;
+}
+
+TargetJITInfo::LazyResolverFn
+ARMJITInfo::getLazyResolverFunction(JITCompilerFn F) {
+ JITCompilerFunction = F;
+ return ARMCompilationCallback;
+}
+
+void *ARMJITInfo::emitFunctionStub(void *Fn, MachineCodeEmitter &MCE) {
+ unsigned addr = (intptr_t)Fn-MCE.getCurrentPCValue()-4;
+ // If this is just a call to an external function, emit a branch instead of a
+ // call. The code is the same except for one bit of the last instruction.
+ if (Fn != (void*)(intptr_t)ARMCompilationCallback) {
+ MCE.startFunctionStub(4, 2);
+ MCE.emitByte(0xEA); // branch to the corresponding function addr
+ MCE.emitByte((unsigned char)(addr >> 0));
+ MCE.emitByte((unsigned char)(addr >> 8));
+ MCE.emitByte((unsigned char)(addr >> 16));
+ return MCE.finishFunctionStub(0);
+ } else {
+ MCE.startFunctionStub(5, 2);
+ MCE.emitByte(0xEB); // branch and link to the corresponding function addr
+ }
+ MCE.emitByte((unsigned char)(addr >> 0));
+ MCE.emitByte((unsigned char)(addr >> 8));
+ MCE.emitByte((unsigned char)(addr >> 16));
+
+ 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 ARMJITInfo::relocate(void *Function, MachineRelocation *MR,
+ unsigned NumRelocs, unsigned char* GOTBase) {
+
+}