[llvm-branch-commits] [llvm-branch] r257779 - Merging r257730:

Hans Wennborg via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Thu Jan 14 09:52:28 PST 2016


Author: hans
Date: Thu Jan 14 11:52:28 2016
New Revision: 257779

URL: http://llvm.org/viewvc/llvm-project?rev=257779&view=rev
Log:
Merging r257730:
------------------------------------------------------------------------
r257730 | majnemer | 2016-01-13 17:20:03 -0800 (Wed, 13 Jan 2016) | 11 lines

[X86] Don't alter HasOpaqueSPAdjustment after we've relied on it

We rely on HasOpaqueSPAdjustment not changing after we've calculated
things based on it.  Things like whether or not we can use 'rep;movs' to
copy bytes around, that sort of thing.  If it changes, invariants in the
backend will quietly break.  This situation arose when we had a call to
memcpy *and* a COPY of the FLAGS register where we would attempt to
reference local variables using %esi, a register that was clobbered by
the 'rep;movs'.

This fixes PR26124.
------------------------------------------------------------------------

Added:
    llvm/branches/release_38/test/CodeGen/X86/x86-repmov-copy-eflags.ll
      - copied unchanged from r257730, llvm/trunk/test/CodeGen/X86/x86-repmov-copy-eflags.ll
Modified:
    llvm/branches/release_38/   (props changed)
    llvm/branches/release_38/include/llvm/CodeGen/MachineFrameInfo.h
    llvm/branches/release_38/include/llvm/Target/TargetLowering.h
    llvm/branches/release_38/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    llvm/branches/release_38/lib/Target/X86/X86FrameLowering.cpp
    llvm/branches/release_38/lib/Target/X86/X86ISelLowering.cpp

Propchange: llvm/branches/release_38/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Thu Jan 14 11:52:28 2016
@@ -1,3 +1,3 @@
 /llvm/branches/Apple/Pertwee:110850,110961
 /llvm/branches/type-system-rewrite:133420-134817
-/llvm/trunk:155241,257645,257648
+/llvm/trunk:155241,257645,257648,257730

Modified: llvm/branches/release_38/include/llvm/CodeGen/MachineFrameInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_38/include/llvm/CodeGen/MachineFrameInfo.h?rev=257779&r1=257778&r2=257779&view=diff
==============================================================================
--- llvm/branches/release_38/include/llvm/CodeGen/MachineFrameInfo.h (original)
+++ llvm/branches/release_38/include/llvm/CodeGen/MachineFrameInfo.h Thu Jan 14 11:52:28 2016
@@ -251,6 +251,10 @@ class MachineFrameInfo {
   /// opaque mechanism like inline assembly or Win32 EH.
   bool HasOpaqueSPAdjustment;
 
+  /// True if the function contains operations which will lower down to
+  /// instructions which manipulate the stack pointer.
+  bool HasCopyImplyingStackAdjustment;
+
   /// True if the function contains a call to the llvm.vastart intrinsic.
   bool HasVAStart;
 
@@ -288,6 +292,7 @@ public:
     LocalFrameMaxAlign = 0;
     UseLocalStackAllocationBlock = false;
     HasOpaqueSPAdjustment = false;
+    HasCopyImplyingStackAdjustment = false;
     HasVAStart = false;
     HasMustTailInVarArgFunc = false;
     Save = nullptr;
@@ -493,6 +498,15 @@ public:
   bool hasOpaqueSPAdjustment() const { return HasOpaqueSPAdjustment; }
   void setHasOpaqueSPAdjustment(bool B) { HasOpaqueSPAdjustment = B; }
 
+  /// Returns true if the function contains operations which will lower down to
+  /// instructions which manipulate the stack pointer.
+  bool hasCopyImplyingStackAdjustment() const {
+    return HasCopyImplyingStackAdjustment;
+  }
+  void setHasCopyImplyingStackAdjustment(bool B) {
+    HasCopyImplyingStackAdjustment = B;
+  }
+
   /// Returns true if the function calls the llvm.va_start intrinsic.
   bool hasVAStart() const { return HasVAStart; }
   void setHasVAStart(bool B) { HasVAStart = B; }

Modified: llvm/branches/release_38/include/llvm/Target/TargetLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_38/include/llvm/Target/TargetLowering.h?rev=257779&r1=257778&r2=257779&view=diff
==============================================================================
--- llvm/branches/release_38/include/llvm/Target/TargetLowering.h (original)
+++ llvm/branches/release_38/include/llvm/Target/TargetLowering.h Thu Jan 14 11:52:28 2016
@@ -2270,7 +2270,7 @@ public:
   }
 
   /// Return true if the MachineFunction contains a COPY which would imply
-  /// HasOpaqueSPAdjustment.
+  /// HasCopyImplyingStackAdjustment.
   virtual bool hasCopyImplyingStackAdjustment(MachineFunction *MF) const {
     return false;
   }

Modified: llvm/branches/release_38/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_38/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=257779&r1=257778&r2=257779&view=diff
==============================================================================
--- llvm/branches/release_38/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
+++ llvm/branches/release_38/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Thu Jan 14 11:52:28 2016
@@ -634,7 +634,7 @@ bool SelectionDAGISel::runOnMachineFunct
   }
 
   if (TLI->hasCopyImplyingStackAdjustment(MF))
-    MFI->setHasOpaqueSPAdjustment(true);
+    MFI->setHasCopyImplyingStackAdjustment(true);
 
   // Freeze the set of reserved registers now that MachineFrameInfo has been
   // set up. All the information required by getReservedRegs() should be

Modified: llvm/branches/release_38/lib/Target/X86/X86FrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_38/lib/Target/X86/X86FrameLowering.cpp?rev=257779&r1=257778&r2=257779&view=diff
==============================================================================
--- llvm/branches/release_38/lib/Target/X86/X86FrameLowering.cpp (original)
+++ llvm/branches/release_38/lib/Target/X86/X86FrameLowering.cpp Thu Jan 14 11:52:28 2016
@@ -91,7 +91,8 @@ bool X86FrameLowering::hasFP(const Machi
           MFI->isFrameAddressTaken() || MFI->hasOpaqueSPAdjustment() ||
           MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
           MMI.callsUnwindInit() || MMI.hasEHFunclets() || MMI.callsEHReturn() ||
-          MFI->hasStackMap() || MFI->hasPatchPoint());
+          MFI->hasStackMap() || MFI->hasPatchPoint() ||
+          MFI->hasCopyImplyingStackAdjustment());
 }
 
 static unsigned getSUBriOpcode(unsigned IsLP64, int64_t Imm) {
@@ -943,11 +944,11 @@ void X86FrameLowering::emitPrologue(Mach
   // push and pop from the stack.
   if (Is64Bit && !Fn->hasFnAttribute(Attribute::NoRedZone) &&
       !TRI->needsStackRealignment(MF) &&
-      !MFI->hasVarSizedObjects() &&    // No dynamic alloca.
-      !MFI->adjustsStack() &&          // No calls.
-      !IsWin64CC &&                    // Win64 has no Red Zone
-      !MFI->hasOpaqueSPAdjustment() && // Don't push and pop.
-      !MF.shouldSplitStack()) {        // Regular stack
+      !MFI->hasVarSizedObjects() &&             // No dynamic alloca.
+      !MFI->adjustsStack() &&                   // No calls.
+      !IsWin64CC &&                             // Win64 has no Red Zone
+      !MFI->hasCopyImplyingStackAdjustment() && // Don't push and pop.
+      !MF.shouldSplitStack()) {                 // Regular stack
     uint64_t MinSize = X86FI->getCalleeSavedFrameSize();
     if (HasFP) MinSize += SlotSize;
     StackSize = std::max(MinSize, StackSize > 128 ? StackSize - 128 : 0);

Modified: llvm/branches/release_38/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_38/lib/Target/X86/X86ISelLowering.cpp?rev=257779&r1=257778&r2=257779&view=diff
==============================================================================
--- llvm/branches/release_38/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/branches/release_38/lib/Target/X86/X86ISelLowering.cpp Thu Jan 14 11:52:28 2016
@@ -17458,7 +17458,7 @@ static SDValue LowerINTRINSIC_W_CHAIN(SD
       // We need a frame pointer because this will get lowered to a PUSH/POP
       // sequence.
       MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
-      MFI->setHasOpaqueSPAdjustment(true);
+      MFI->setHasCopyImplyingStackAdjustment(true);
       // Don't do anything here, we will expand these intrinsics out later
       // during ExpandISelPseudos in EmitInstrWithCustomInserter.
       return SDValue();




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