commit d1643e41ef242ae656f667bf3c8b0324635cefd3
author buzbee <buzbee@google.com> Wed Sep 05 14:06:51 2012 -0700
committer buzbee <buzbee@google.com> Sun Sep 09 13:57:33 2012 -0700
tree 6a14d7abb876c850129117304ea33afd619a0eb3
parent 22f454c7d349c439c774c5d79b32514b190fd531

Basic block combine pass

Combine basic blocks terminated by instruction that we have since
proven not to throw.  This change is intended to relieve some of the
computational load for llvm by reducing the number of basic blocks
it has to contend with.

Also:
  Add stats to show how successful check elimination is.
  Restore mechanism to disable some expensive optimization passes when
  compiling large methods.

Change-Id: I7fae22160988cbefb90ea9fb1cc26d7364e8d229

src/compiler/codegen/MethodCodegenDriver.cc

diff --git a/src/compiler/codegen/MethodCodegenDriver.cc b/src/compiler/codegen/MethodCodegenDriver.cc
index b4e14ce..e76834d 100644
--- a/src/compiler/codegen/MethodCodegenDriver.cc
+++ b/src/compiler/codegen/MethodCodegenDriver.cc
@@ -881,14 +881,7 @@
   oatResetRegPool(cUnit);
   oatResetDefTracking(cUnit);
 
-  /*
-   * If control reached us from our immediate predecessor via
-   * fallthrough and we have no other incoming arcs we can
-   * reuse existing liveness.  Otherwise, reset.
-   */
-  if (!bb->fallThroughTarget || bb->predecessors->numUsed != 1) {
-    oatClobberAllRegs(cUnit);
-  }
+  oatClobberAllRegs(cUnit);
 
   LIR* headLIR = NULL;
 
@@ -922,9 +915,7 @@
     /* Mark the beginning of a Dalvik instruction for line tracking */
     char* instStr = cUnit->printMe ?
        oatGetDalvikDisassembly(cUnit, mir->dalvikInsn, "") : NULL;
-    boundaryLIR = newLIR1(cUnit, kPseudoDalvikByteCodeBoundary,
-                          (intptr_t) instStr);
-    cUnit->boundaryMap.Overwrite(mir->offset, boundaryLIR);
+    boundaryLIR = markBoundary(cUnit, mir->offset, instStr);
     /* Remember the first LIR for this block */
     if (headLIR == NULL) {
       headLIR = boundaryLIR;