commit ad8f15e0b13383b2eaa2486b230debeae7a55661
author buzbee <buzbee@google.com> Mon Jun 18 14:49:45 2012 -0700
committer buzbee <buzbee@google.com> Wed Jun 20 15:12:44 2012 -0700
tree 0939aa6dee5f24dc4ae21dd2c06db0265d4682ca
parent 83c26f9c7ee42b0037d2679f6f37dd28a3f13af7

Milestone: close Quick side channel communication

This CL elminates side-channel communication between the Quick
Compiler's Dex->MIR->LLVM-IR and LLVM-IR->LIR lowering stages by clearing
key data structures between the two stages.

The purpose if to flush out any hidden information transfer, and thus
ensure that the GreenlandIR representation of the program is sufficient.

Note that as of this change, we've lost all register promotion info
so the Quick compiler will generate non-promoted code.  A near-future
CL will restore that info from the MethodInfo intrinsic.

Change-Id: I797845f1fc029bc03aac3ec20f8cd81f917817ca

src/compiler/Ralloc.cc

diff --git a/src/compiler/Ralloc.cc b/src/compiler/Ralloc.cc
index 29766e0..0062f53 100644
--- a/src/compiler/Ralloc.cc
+++ b/src/compiler/Ralloc.cc
@@ -339,6 +339,17 @@
                                      INVALID_REG, INVALID_REG, INVALID_SREG,
                                      INVALID_SREG};
 
+int oatComputeFrameSize(CompilationUnit* cUnit) {
+  /* Figure out the frame size */
+  static const uint32_t kAlignMask = kStackAlignment - 1;
+  uint32_t size = (cUnit->numCoreSpills + cUnit->numFPSpills +
+                   1 /* filler word */ + cUnit->numRegs + cUnit->numOuts +
+                   cUnit->numCompilerTemps + 1 /* curMethod* */)
+                   * sizeof(uint32_t);
+  /* Align and set */
+  return (size + kAlignMask) & ~(kAlignMask);
+}
+
 /*
  * Simple register allocation.  Some Dalvik virtual registers may
  * be promoted to physical registers.  Most of the work for temp
@@ -459,19 +470,16 @@
 
   oatDoPromotion(cUnit);
 
+  /* Get easily-accessable post-promotion copy of RegLocation for Method* */
+  cUnit->methodLoc = cUnit->regLocation[cUnit->methodSReg];
+
   if (cUnit->printMe && !(cUnit->disableOpt & (1 << kPromoteRegs))) {
     LOG(INFO) << "After Promotion";
     oatDumpRegLocTable(cUnit->regLocation, cUnit->numSSARegs);
   }
 
-  /* Figure out the frame size */
-  static const uint32_t kAlignMask = kStackAlignment - 1;
-  uint32_t size = (cUnit->numCoreSpills + cUnit->numFPSpills +
-                   1 /* filler word */ + cUnit->numRegs + cUnit->numOuts +
-                   cUnit->numCompilerTemps + 1 /* curMethod* */)
-                   * sizeof(uint32_t);
-  /* Align and set */
-  cUnit->frameSize = (size + kAlignMask) & ~(kAlignMask);
+  /* Set the frame size */
+  cUnit->frameSize = oatComputeFrameSize(cUnit);
 }
 
 }  // namespace art