X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=docs%2FStackMaps.rst;h=bd0fb946f9a50ea1bd5f4674aabe498ef24d7999;hb=75277b9f70a086b0dcdf5c71cdca6d58e9d29941;hp=0dac62b595d02c488d0f55baa5492dbf6e9eda23;hpb=e97b13228a46d1ae76cb77d8749f9867f817ebeb;p=oota-llvm.git

diff --git a/docs/StackMaps.rst b/docs/StackMaps.rst
index 0dac62b595d..bd0fb946f9a 100644
--- a/docs/StackMaps.rst
+++ b/docs/StackMaps.rst
@@ -313,12 +313,21 @@ format of this section follows:
 
 .. code-block:: none
 
-  uint32 : Reserved (header)
+  Header {
+    uint8  : Stack Map Version (current version is 1)
+    uint8  : Reserved (expected to be 0)
+    uint16 : Reserved (expected to be 0)
+  }
+  uint32 : NumFunctions
   uint32 : NumConstants
+  uint32 : NumRecords
+  StkSizeRecord[NumFunctions] {
+    uint64 : Function Address
+    uint64 : Stack Size
+  }
   Constants[NumConstants] {
     uint64 : LargeConstant
   }
-  uint32 : NumRecords
   StkMapRecord[NumRecords] {
     uint64 : PatchPoint ID
     uint32 : Instruction Offset
@@ -330,12 +339,14 @@ format of this section follows:
       uint16 : Dwarf RegNum
       int32  : Offset or SmallConstant
     }
+    uint16 : Padding
     uint16 : NumLiveOuts
     LiveOuts[NumLiveOuts]
       uint16 : Dwarf RegNum
       uint8  : Reserved
       uint8  : Size in Bytes
     }
+    uint32 : Padding (only if required to align to 8 byte)
   }
 
 The first byte of each location encodes a type that indicates how to
@@ -389,6 +400,10 @@ immediately after compiling a module and encode the information in its
 own format. Since the runtime controls the allocation of sections, it
 can reuse the same stack map space for multiple modules.
 
+Stackmap support is currently only implemented for 64-bit
+platforms. However, a 32-bit implementation should be able to use the
+same format with an insignificant amount of wasted space.
+
 .. _stackmap-section:
 
 Stack Map Section
@@ -443,10 +458,11 @@ program could crash before the runtime could take back control.
 
 To enforce these semantics, stackmap and patchpoint intrinsics are
 considered to potentially read and write all memory. This may limit
-optimization more than some clients desire. To address this problem
-meta-data could be added to the intrinsic call to express aliasing,
-thereby allowing optimizations to hoist certain loads above stack
-maps.
+optimization more than some clients desire. This limitation may be
+avoided by marking the call site as "readonly". In the future we may
+also allow meta-data to be added to the intrinsic call to express
+aliasing, thereby allowing optimizations to hoist certain loads above
+stack maps.
 
 Direct Stack Map Entries
 ^^^^^^^^^^^^^^^^^^^^^^^^