本文整理汇总了C++中AArch64FunctionInfo::setStackRealigned方法的典型用法代码示例。如果您正苦于以下问题：C++ AArch64FunctionInfo::setStackRealigned方法的具体用法？C++ AArch64FunctionInfo::setStackRealigned怎么用？C++ AArch64FunctionInfo::setStackRealigned使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类AArch64FunctionInfo的用法示例。
在下文中一共展示了AArch64FunctionInfo::setStackRealigned方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: hasFP
//.........这里部分代码省略.........
if (NeedsRealignment) {
scratchSPReg = findScratchNonCalleeSaveRegister(&MBB);
assert(scratchSPReg != AArch64::NoRegister);
}
// If we're a leaf function, try using the red zone.
if (!canUseRedZone(MF))
// FIXME: in the case of dynamic re-alignment, NumBytes doesn't have
// the correct value here, as NumBytes also includes padding bytes,
// which shouldn't be counted here.
emitFrameOffset(MBB, MBBI, DL, scratchSPReg, AArch64::SP, -NumBytes, TII,
MachineInstr::FrameSetup);
if (NeedsRealignment) {
const unsigned Alignment = MFI->getMaxAlignment();
const unsigned NrBitsToZero = countTrailingZeros(Alignment);
assert(NrBitsToZero > 1);
assert(scratchSPReg != AArch64::SP);
// SUB X9, SP, NumBytes
// -- X9 is temporary register, so shouldn't contain any live data here,
// -- free to use. This is already produced by emitFrameOffset above.
// AND SP, X9, 0b11111...0000
// The logical immediates have a non-trivial encoding. The following
// formula computes the encoded immediate with all ones but
// NrBitsToZero zero bits as least significant bits.
uint32_t andMaskEncoded = (1 << 12) // = N
| ((64 - NrBitsToZero) << 6) // immr
| ((64 - NrBitsToZero - 1) << 0); // imms
BuildMI(MBB, MBBI, DL, TII->get(AArch64::ANDXri), AArch64::SP)
.addReg(scratchSPReg, RegState::Kill)
.addImm(andMaskEncoded);
AFI->setStackRealigned(true);
}
}
// If we need a base pointer, set it up here. It's whatever the value of the
// stack pointer is at this point. Any variable size objects will be allocated
// after this, so we can still use the base pointer to reference locals.
//
// FIXME: Clarify FrameSetup flags here.
// Note: Use emitFrameOffset() like above for FP if the FrameSetup flag is
// needed.
if (RegInfo->hasBasePointer(MF)) {
TII->copyPhysReg(MBB, MBBI, DL, RegInfo->getBaseRegister(), AArch64::SP,
false);
}
if (needsFrameMoves) {
const DataLayout &TD = MF.getDataLayout();
const int StackGrowth = -TD.getPointerSize(0);
unsigned FramePtr = RegInfo->getFrameRegister(MF);
// An example of the prologue:
//
// .globl __foo
// .align 2
// __foo:
// Ltmp0:
// .cfi_startproc
// .cfi_personality 155, ___gxx_personality_v0
// Leh_func_begin:
// .cfi_lsda 16, Lexception33
//
// stp xa,bx, [sp, -#offset]!
// ...