Move estimateStackSize from ARM into MachineFrameInfo
This is a generic function (derived from PEI); moving it into
MachineFrameInfo eliminates a current redundancy between the ARM and AArch64
backends, and will allow it to be used by the PowerPC target code.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177111 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 5e04f2d..04321f3 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -574,6 +574,54 @@
return BV;
}
+unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
+ const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+ const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
+ unsigned MaxAlign = getMaxAlignment();
+ int Offset = 0;
+
+ // This code is very, very similar to PEI::calculateFrameObjectOffsets().
+ // It really should be refactored to share code. Until then, changes
+ // should keep in mind that there's tight coupling between the two.
+
+ for (int i = getObjectIndexBegin(); i != 0; ++i) {
+ int FixedOff = -getObjectOffset(i);
+ if (FixedOff > Offset) Offset = FixedOff;
+ }
+ for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
+ if (isDeadObjectIndex(i))
+ continue;
+ Offset += getObjectSize(i);
+ unsigned Align = getObjectAlignment(i);
+ // Adjust to alignment boundary
+ Offset = (Offset+Align-1)/Align*Align;
+
+ MaxAlign = std::max(Align, MaxAlign);
+ }
+
+ if (adjustsStack() && TFI->hasReservedCallFrame(MF))
+ Offset += getMaxCallFrameSize();
+
+ // Round up the size to a multiple of the alignment. If the function has
+ // any calls or alloca's, align to the target's StackAlignment value to
+ // ensure that the callee's frame or the alloca data is suitably aligned;
+ // otherwise, for leaf functions, align to the TransientStackAlignment
+ // value.
+ unsigned StackAlign;
+ if (adjustsStack() || hasVarSizedObjects() ||
+ (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
+ StackAlign = TFI->getStackAlignment();
+ else
+ StackAlign = TFI->getTransientStackAlignment();
+
+ // If the frame pointer is eliminated, all frame offsets will be relative to
+ // SP not FP. Align to MaxAlign so this works.
+ StackAlign = std::max(StackAlign, MaxAlign);
+ unsigned AlignMask = StackAlign - 1;
+ Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
+
+ return (unsigned)Offset;
+}
void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
if (Objects.empty()) return;