Add extra operand to CALLSEQ_START to keep frame part set up previously

Using arguments with attribute inalloca creates problems for verification
of machine representation. This attribute instructs the backend that the
argument is prepared in stack prior to  CALLSEQ_START..CALLSEQ_END
sequence (see http://llvm.org/docs/InAlloca.htm for details). Frame size
stored in CALLSEQ_START in this case does not count the size of this
argument. However CALLSEQ_END still keeps total frame size, as caller can
be responsible for cleanup of entire frame. So CALLSEQ_START and
CALLSEQ_END keep different frame size and the difference is treated by
MachineVerifier as stack error. Currently there is no way to distinguish
this case from actual errors.

This patch adds additional argument to CALLSEQ_START and its
target-specific counterparts to keep size of stack that is set up prior to
the call frame sequence. This argument allows MachineVerifier to calculate
actual frame size associated with frame setup instruction and correctly
process the case of inalloca arguments.

The changes made by the patch are:
- Frame setup instructions get the second mandatory argument. It
  affects all targets that use frame pseudo instructions and touched many
  files although the changes are uniform.
- Access to frame properties are implemented using special instructions
  rather than calls getOperand(N).getImm(). For X86 and ARM such
  replacement was made previously.
- Changes that reflect appearance of additional argument of frame setup
  instruction. These involve proper instruction initialization and
  methods that access instruction arguments.
- MachineVerifier retrieves frame size using method, which reports sum of
  frame parts initialized inside frame instruction pair and outside it.

The patch implements approach proposed by Quentin Colombet in
https://bugs.llvm.org/show_bug.cgi?id=27481#c1.
It fixes 9 tests failed with machine verifier enabled and listed
in PR27481.

Differential Revision: https://reviews.llvm.org/D32394

llvm-svn: 302527

6 files changed, 13 insertions, 23 deletions

diff --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.h b/llvm/lib/Target/ARM/ARMBaseInstrInfo.h
index 28c407f7412..dd7fe871345 100644
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.h
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.h
@@ -404,21 +404,11 @@ public:
   /// Returns predicate register associated with the given frame instruction.
   unsigned getFramePred(const MachineInstr &MI) const {
     assert(isFrameInstr(MI));
-    if (isFrameSetup(MI))
-      // Operands of ADJCALLSTACKDOWN:
-      // - argument declared in ADJCALLSTACKDOWN pattern:
-      // 0 - frame size
-      // 1 - predicate code (like ARMCC::AL)
-      // - added by predOps:
-      // 2 - predicate reg
-      return MI.getOperand(2).getReg();
-    assert(MI.getOpcode() == ARM::ADJCALLSTACKUP ||
-           MI.getOpcode() == ARM::tADJCALLSTACKUP);
-    // Operands of ADJCALLSTACKUP:
-    // - argument declared in ADJCALLSTACKUP pattern:
+    // Operands of ADJCALLSTACKDOWN/ADJCALLSTACKUP:
+    // - argument declared in the pattern:
     // 0 - frame size
-    // 1 - arg of CALLSEQ_END
-    // 2 - predicate code
+    // 1 - arg of CALLSEQ_START/CALLSEQ_END
+    // 2 - predicate code (like ARMCC::AL)
     // - added by predOps:
     // 3 - predicate reg
     return MI.getOperand(3).getReg();
diff --git a/llvm/lib/Target/ARM/ARMCallLowering.cpp b/llvm/lib/Target/ARM/ARMCallLowering.cpp
index 9178c67afa6..46ac4d0ad93 100644
--- a/llvm/lib/Target/ARM/ARMCallLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMCallLowering.cpp
@@ -433,7 +433,7 @@ bool ARMCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
 
   // We now know the size of the stack - update the ADJCALLSTACKDOWN
   // accordingly.
-  CallSeqStart.addImm(ArgHandler.StackSize).add(predOps(ARMCC::AL));
+  CallSeqStart.addImm(ArgHandler.StackSize).addImm(0).add(predOps(ARMCC::AL));
 
   MIRBuilder.buildInstr(ARM::ADJCALLSTACKUP)
       .addImm(ArgHandler.StackSize)
diff --git a/llvm/lib/Target/ARM/ARMFastISel.cpp b/llvm/lib/Target/ARM/ARMFastISel.cpp
index 56cac855620..4f6a73b5980 100644
--- a/llvm/lib/Target/ARM/ARMFastISel.cpp
+++ b/llvm/lib/Target/ARM/ARMFastISel.cpp
@@ -1949,7 +1949,7 @@ bool ARMFastISel::ProcessCallArgs(SmallVectorImpl<Value*> &Args,
   unsigned AdjStackDown = TII.getCallFrameSetupOpcode();
   AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
                           TII.get(AdjStackDown))
-                  .addImm(NumBytes));
+                  .addImm(NumBytes).addImm(0));
 
   // Process the args.
   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index e5c4d86ed92..69b511d5add 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -1817,8 +1817,7 @@ ARMTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   // Adjust the stack pointer for the new arguments...
   // These operations are automatically eliminated by the prolog/epilog pass
   if (!isSibCall)
-    Chain = DAG.getCALLSEQ_START(Chain,
-                                 DAG.getIntPtrConstant(NumBytes, dl, true), dl);
+    Chain = DAG.getCALLSEQ_START(Chain, NumBytes, 0, dl);
 
   SDValue StackPtr =
       DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy(DAG.getDataLayout()));
diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td
index a94d6048f02..d06b7d0896f 100644
--- a/llvm/lib/Target/ARM/ARMInstrInfo.td
+++ b/llvm/lib/Target/ARM/ARMInstrInfo.td
@@ -16,7 +16,8 @@
 //
 
 // Type profiles.
-def SDT_ARMCallSeqStart : SDCallSeqStart<[ SDTCisVT<0, i32> ]>;
+def SDT_ARMCallSeqStart : SDCallSeqStart<[ SDTCisVT<0, i32>,
+                                           SDTCisVT<1, i32> ]>;
 def SDT_ARMCallSeqEnd   : SDCallSeqEnd<[ SDTCisVT<0, i32>, SDTCisVT<1, i32> ]>;
 def SDT_ARMStructByVal : SDTypeProfile<0, 4,
                                        [SDTCisVT<0, i32>, SDTCisVT<1, i32>,
@@ -1968,8 +1969,8 @@ PseudoInst<(outs), (ins i32imm:$amt1, i32imm:$amt2, pred:$p), NoItinerary,
            [(ARMcallseq_end timm:$amt1, timm:$amt2)]>;
 
 def ADJCALLSTACKDOWN :
-PseudoInst<(outs), (ins i32imm:$amt, pred:$p), NoItinerary,
-           [(ARMcallseq_start timm:$amt)]>;
+PseudoInst<(outs), (ins i32imm:$amt, i32imm:$amt2, pred:$p), NoItinerary,
+           [(ARMcallseq_start timm:$amt, timm:$amt2)]>;
 }
 
 def HINT : AI<(outs), (ins imm0_239:$imm), MiscFrm, NoItinerary,
diff --git a/llvm/lib/Target/ARM/ARMInstrThumb.td b/llvm/lib/Target/ARM/ARMInstrThumb.td
index 8048c758e99..bee83dfb6f6 100644
--- a/llvm/lib/Target/ARM/ARMInstrThumb.td
+++ b/llvm/lib/Target/ARM/ARMInstrThumb.td
@@ -284,8 +284,8 @@ def tADJCALLSTACKUP :
             Requires<[IsThumb, IsThumb1Only]>;
 
 def tADJCALLSTACKDOWN :
-  PseudoInst<(outs), (ins i32imm:$amt), NoItinerary,
-             [(ARMcallseq_start imm:$amt)]>,
+  PseudoInst<(outs), (ins i32imm:$amt, i32imm:$amt2), NoItinerary,
+             [(ARMcallseq_start imm:$amt, imm:$amt2)]>,
             Requires<[IsThumb, IsThumb1Only]>;
 }