Fixups

Author: MacDue

llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h

@@ -315,6 +315,8 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
   }
 
   void setStackSizeSVE(uint64_t ZPR, uint64_t PPR) {
+    assert(isAligned(Align(16), ZPR) && isAligned(Align(16), PPR) &&
+           "expected SVE stack sizes to be aligned to 16-bytes");
     StackSizeZPR = ZPR;
     StackSizePPR = PPR;
     HasCalculatedStackSizeSVE = true;
@@ -425,6 +427,8 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
 
   // Saves the CalleeSavedStackSize for SVE vectors in 'scalable bytes'
   void setSVECalleeSavedStackSize(unsigned ZPR, unsigned PPR) {
+    assert(isAligned(Align(16), ZPR) && isAligned(Align(16), PPR) &&
+           "expected SVE callee-save sizes to be aligned to 16-bytes");
     ZPRCalleeSavedStackSize = ZPR;
     PPRCalleeSavedStackSize = PPR;
     HasSVECalleeSavedStackSize = true;

llvm/lib/Target/AArch64/AArch64PrologueEpilogue.cpp

@@ -799,8 +799,10 @@ void AArch64PrologueEmitter::emitPrologue() {
                            NonSVELocalsSize);
     CFAOffset += AllocateAfterPPRs;
   } else {
-    // Note: With CalleeSavesAboveFrameRecord the SVE CS have already been
-    // allocated (and separate PPRLocals are not supported).
+    assert(SVELayout == SVEStackLayout::CalleeSavesAboveFrameRecord);
+    // Note: With CalleeSavesAboveFrameRecord, the SVE CS have already been
+    // allocated (and separate PPR locals are not supported, all SVE locals,
+    // both PPR and ZPR, are within the ZPR locals area).
     assert(!PPR.LocalsSize && "Unexpected PPR locals!");
     CFAOffset += SVECalleeSavesSize;
   }
@@ -1276,6 +1278,8 @@ void AArch64PrologueEmitter::emitCalleeSavedSVELocations(
         StackOffset::getScalable(MFI.getObjectOffset(FI)) -
         StackOffset::getFixed(AFI->getCalleeSavedStackSize(MFI));
 
+    // The scalable vectors are below (lower address) the scalable predicates
+    // with split SVE objects, so we must subtract the size of the predicates.
     if (SVELayout == SVEStackLayout::Split &&
         MFI.getStackID(FI) == TargetStackID::ScalableVector)
       Offset -= PPRStackSize;