Implement MipsJITInfo::replaceMachineCodeForFunction.

No new test case is added.
This patch makes test JITTest.FunctionIsRecompiledAndRelinked pass on mips
platform.

Patch by Petar Jovanovic.

llvm-svn: 161098
This commit is contained in:
Akira Hatanaka 2012-08-01 02:29:24 +00:00
parent e5d91bee71
commit 731add334a
2 changed files with 48 additions and 3 deletions

View File

@ -27,7 +27,52 @@ using namespace llvm;
void MipsJITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
report_fatal_error("MipsJITInfo::replaceMachineCodeForFunction");
unsigned NewAddr = (intptr_t)New;
unsigned OldAddr = (intptr_t)Old;
const unsigned NopInstr = 0x0;
// If the functions are in the same memory segment, insert PC-region branch.
if ((NewAddr & 0xF0000000) == ((OldAddr + 4) & 0xF0000000)) {
unsigned *OldInstruction = (unsigned *)Old;
*OldInstruction = 0x08000000;
unsigned JTargetAddr = NewAddr & 0x0FFFFFFC;
JTargetAddr >>= 2;
*OldInstruction |= JTargetAddr;
// Insert a NOP.
OldInstruction++;
*OldInstruction = NopInstr;
sys::Memory::InvalidateInstructionCache(Old, 2 * 4);
} else {
// We need to clear hint bits from the instruction, in case it is 'jr ra'.
const unsigned HintMask = 0xFFFFF83F, ReturnSequence = 0x03e00008;
unsigned* CurrentInstr = (unsigned*)Old;
unsigned CurrInstrHintClear = (*CurrentInstr) & HintMask;
unsigned* NextInstr = CurrentInstr + 1;
unsigned NextInstrHintClear = (*NextInstr) & HintMask;
// Do absolute jump if there are 2 or more instructions before return from
// the old function.
if ((CurrInstrHintClear != ReturnSequence) &&
(NextInstrHintClear != ReturnSequence)) {
const unsigned LuiT0Instr = 0x3c080000, AddiuT0Instr = 0x25080000;
const unsigned JrT0Instr = 0x01000008;
// lui t0, high 16 bit of the NewAddr
(*(CurrentInstr++)) = LuiT0Instr | ((NewAddr & 0xffff0000) >> 16);
// addiu t0, t0, low 16 bit of the NewAddr
(*(CurrentInstr++)) = AddiuT0Instr | (NewAddr & 0x0000ffff);
// jr t0
(*(CurrentInstr++)) = JrT0Instr;
(*CurrentInstr) = NopInstr;
sys::Memory::InvalidateInstructionCache(Old, 4 * 4);
} else {
// Unsupported case
report_fatal_error("MipsJITInfo::replaceMachineCodeForFunction");
}
}
}
/// JITCompilerFunction - This contains the address of the JIT function used to

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@ -555,10 +555,10 @@ TEST_F(JITTest, FunctionPointersOutliveTheirCreator) {
#endif
}
// ARM and MIPS do not have an implementation
// ARM does not have an implementation
// of replaceMachineCodeForFunction(), so recompileAndRelinkFunction
// doesn't work.
#if !defined(__arm__) && !defined(__mips__)
#if !defined(__arm__)
TEST_F(JITTest, FunctionIsRecompiledAndRelinked) {
Function *F = Function::Create(TypeBuilder<int(void), false>::get(Context),
GlobalValue::ExternalLinkage, "test", M);