Do not model all INLINEASM instructions as having unmodelled side effects.

Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.

This allows memory instructions to be moved around INLINEASM instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123044 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 20 insertions, 2 deletions

diff --git a/include/llvm/CodeGen/ISDOpcodes.h b/include/llvm/CodeGen/ISDOpcodes.h
index 7236bd5717..ac3d87c4bd 100644
--- a/include/llvm/CodeGen/ISDOpcodes.h
+++ b/include/llvm/CodeGen/ISDOpcodes.h
@@ -482,7 +482,7 @@ namespace ISD {
     //   Operand #0   : Input chain.
     //   Operand #1   : a ExternalSymbolSDNode with a pointer to the asm string.
     //   Operand #2   : a MDNodeSDNode with the !srcloc metadata.
-    //   Operand #3   : IsAlignStack bit.
+    //   Operand #3   : HasSideEffect, IsAlignStack bits.
     //   After this, it is followed by a list of operands with this format:
     //     ConstantSDNode: Flags that encode whether it is a mem or not, the
     //                     of operands that follow, etc.  See InlineAsm.h.
diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index fc1e211af1..82c5332ccd 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -237,6 +237,7 @@ public:
   bool isKill() const { return getOpcode() == TargetOpcode::KILL; }
   bool isImplicitDef() const { return getOpcode()==TargetOpcode::IMPLICIT_DEF; }
   bool isInlineAsm() const { return getOpcode() == TargetOpcode::INLINEASM; }
+  bool isStackAligningInlineAsm() const;
   bool isInsertSubreg() const {
     return getOpcode() == TargetOpcode::INSERT_SUBREG;
   }
@@ -432,6 +433,15 @@ public:
   /// return 0.
   unsigned isConstantValuePHI() const;
 
+  /// hasUnmodeledSideEffects - Return true if this instruction has side
+  /// effects that are not modeled by mayLoad / mayStore, etc.
+  /// For all instructions, the property is encoded in TargetInstrDesc::Flags
+  /// (see TargetInstrDesc::hasUnmodeledSideEffects(). The only exception is
+  /// INLINEASM instruction, in which case the side effect property is encoded
+  /// in one of its operands (see InlineAsm::Extra_HasSideEffect).
+  ///
+  bool hasUnmodeledSideEffects() const;
+
   /// allDefsAreDead - Return true if all the defs of this instruction are dead.
   ///
   bool allDefsAreDead() const;
diff --git a/include/llvm/InlineAsm.h b/include/llvm/InlineAsm.h
index 4ca012e974..ed8f0f7f61 100644
--- a/include/llvm/InlineAsm.h
+++ b/include/llvm/InlineAsm.h
@@ -190,8 +190,15 @@ public:
     Op_InputChain = 0,
     Op_AsmString = 1,
     Op_MDNode = 2,
-    Op_IsAlignStack = 3,
+    Op_ExtraInfo = 3,    // HasSideEffects, IsAlignStack
     Op_FirstOperand = 4,
+
+    MIOp_AsmString = 0,
+    MIOp_ExtraInfo = 1,    // HasSideEffects, IsAlignStack
+    MIOp_FirstOperand = 2,
+
+    Extra_HasSideEffects = 1,
+    Extra_IsAlignStack = 2,
     
     Kind_RegUse = 1,
     Kind_RegDef = 2,
diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td
index e88a09eecc..1bc00b610e 100644
--- a/include/llvm/Target/Target.td
+++ b/include/llvm/Target/Target.td
@@ -418,6 +418,7 @@ def INLINEASM : Instruction {
   let OutOperandList = (outs);
   let InOperandList = (ins variable_ops);
   let AsmString = "";
+  let neverHasSideEffects = 1;  // Note side effect is encoded in an operand.
 }
 def PROLOG_LABEL : Instruction {
   let OutOperandList = (outs);