[inline asm] Implement mayLoad and mayStore for inline assembly. In general,

the MachineInstr MayLoad/MayLoad flags are based on the tablegen implementation.
For inline assembly, however, we need to compute these based on the constraints.

Revert r166929 as this is no longer needed, but leave the test case in place. 
rdar://12033048 and PR13504

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167040 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 3 deletions

diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index eab74bd301..42709012d2 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -58,8 +58,10 @@ public:
     NoFlags      = 0,
     FrameSetup   = 1 << 0,              // Instruction is used as a part of
                                         // function frame setup code.
-    InsideBundle = 1 << 1               // Instruction is inside a bundle (not
+    InsideBundle = 1 << 1,              // Instruction is inside a bundle (not
                                         // the first MI in a bundle)
+    MayLoad      = 1 << 2,              // Instruction could possibly read memory.
+    MayStore     = 1 << 3               // Instruction could possibly modify memory.
   };
 private:
   const MCInstrDesc *MCID;              // Instruction descriptor.
@@ -445,7 +447,7 @@ public:
   /// Instructions with this flag set are not necessarily simple load
   /// instructions, they may load a value and modify it, for example.
   bool mayLoad(QueryType Type = AnyInBundle) const {
-    return hasProperty(MCID::MayLoad, Type);
+    return hasProperty(MCID::MayLoad, Type) || (Flags & MayLoad);
   }
 
 
@@ -454,7 +456,7 @@ public:
   /// instructions, they may store a modified value based on their operands, or
   /// may not actually modify anything, for example.
   bool mayStore(QueryType Type = AnyInBundle) const {
-    return hasProperty(MCID::MayStore, Type);
+    return hasProperty(MCID::MayStore, Type) || (Flags & MayStore);
   }
 
   //===--------------------------------------------------------------------===//