commit d55e115b58addbd13c12bbe451ed66ad57a37387
author Oliver Stannard <oliver.stannard@arm.com> Wed Mar 05 15:25:27 2014 +0000
committer Oliver Stannard <oliver.stannard@arm.com> Wed Mar 05 15:25:27 2014 +0000
tree fcea49b348b86494f385541cf5558a54c8847489
parent 7590be3cfa505775989633fe64d92fa2939f4641

ARM: Correctly align arguments after a byval struct is passed on the stack

llvm-svn: 202985

llvm/lib/Target/ARM/Thumb1FrameLowering.cpp

diff --git a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
index 996428d..009104e 100644
--- a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
+++ b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
@@ -94,6 +94,8 @@
   unsigned Align = MF.getTarget().getFrameLowering()->getStackAlignment();
   unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize(Align);
   unsigned NumBytes = MFI->getStackSize();
+  assert(NumBytes >= ArgRegsSaveSize &&
+         "ArgRegsSaveSize is included in NumBytes");
   const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
   DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
   unsigned FramePtr = RegInfo->getFrameRegister(MF);
@@ -121,13 +123,13 @@
   }
 
   if (!AFI->hasStackFrame()) {
-    if (NumBytes != 0) {
-      emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
+    if (NumBytes - ArgRegsSaveSize != 0) {
+      emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -(NumBytes - ArgRegsSaveSize),
                    MachineInstr::FrameSetup);
       MCSymbol *SPLabel = MMI.getContext().CreateTempSymbol();
       BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::PROLOG_LABEL))
           .addSym(SPLabel);
-      CFAOffset -= NumBytes;
+      CFAOffset -= NumBytes - ArgRegsSaveSize;
       MMI.addFrameInst(
           MCCFIInstruction::createDefCfaOffset(SPLabel, CFAOffset));
     }
@@ -168,7 +170,7 @@
   }
 
   // Determine starting offsets of spill areas.
-  unsigned DPRCSOffset  = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
+  unsigned DPRCSOffset  = NumBytes - ArgRegsSaveSize - (GPRCS1Size + GPRCS2Size + DPRCSSize);
   unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
   unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
   bool HasFP = hasFP(MF);
@@ -219,7 +221,7 @@
     case ARM::LR:
       MMI.addFrameInst(MCCFIInstruction::createOffset(SPLabel,
          MRI->getDwarfRegNum(Reg, true),
-         MFI->getObjectOffset(FI) - ArgRegsSaveSize));
+         MFI->getObjectOffset(FI)));
       break;
     }
   }
@@ -227,7 +229,8 @@
 
   // Adjust FP so it point to the stack slot that contains the previous FP.
   if (HasFP) {
-    FramePtrOffsetInBlock += MFI->getObjectOffset(FramePtrSpillFI) + GPRCS1Size;
+    FramePtrOffsetInBlock += MFI->getObjectOffset(FramePtrSpillFI)
+		                     + GPRCS1Size + ArgRegsSaveSize;
     AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr)
       .addReg(ARM::SP).addImm(FramePtrOffsetInBlock / 4)
       .setMIFlags(MachineInstr::FrameSetup));
@@ -324,12 +327,14 @@
   unsigned Align = MF.getTarget().getFrameLowering()->getStackAlignment();
   unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize(Align);
   int NumBytes = (int)MFI->getStackSize();
+  assert(NumBytes >= ArgRegsSaveSize &&
+         "ArgRegsSaveSize is included in NumBytes");
   const uint16_t *CSRegs = RegInfo->getCalleeSavedRegs();
   unsigned FramePtr = RegInfo->getFrameRegister(MF);
 
   if (!AFI->hasStackFrame()) {
-    if (NumBytes != 0)
-      emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, NumBytes);
+    if (NumBytes - ArgRegsSaveSize != 0)
+      emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, NumBytes - ArgRegsSaveSize);
   } else {
     // Unwind MBBI to point to first LDR / VLDRD.
     if (MBBI != MBB.begin()) {
@@ -343,7 +348,8 @@
     // Move SP to start of FP callee save spill area.
     NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
                  AFI->getGPRCalleeSavedArea2Size() +
-                 AFI->getDPRCalleeSavedAreaSize());
+                 AFI->getDPRCalleeSavedAreaSize() +
+                 ArgRegsSaveSize);
 
     if (AFI->shouldRestoreSPFromFP()) {
       NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;