Use trampolines for calls to helpers

This is an ARM specific optimization to the compiler
that uses trampoline islands to make calls to runtime
helper functions.  The intention is to reduce the size
of the generated code (by 2 bytes per call) without
affecting performance.

By default this is on when generating an OAT file.  It is
off when compiling to memory.

To switch this off in dex2oat, use the command line option:
--no-helper-trampolines

Enhances disassembler to print the trampoline entry on the
BL instruction like this:

0xb6a850c0: f7ffff9e  bl      -196 (0xb6a85000)  ; pTestSuspend

Bug: 12607709
Change-Id: I9202bdb7cf21252ad807bd48701f1f6ce8e3d0fe

1 files changed, 2 insertions, 0 deletions

diff --git a/compiler/dex/compiler_enums.h b/compiler/dex/compiler_enums.h
index 6c8c85d16d..a3ce4f9c54 100644
--- a/compiler/dex/compiler_enums.h
+++ b/compiler/dex/compiler_enums.h
@@ -430,10 +430,12 @@ enum FixupKind {
   kFixupT2Branch,    // Thumb2 Unconditional branch
   kFixupBlx1,        // Blx1 (start of Blx1/Blx2 pair).
   kFixupBl1,         // Bl1 (start of Bl1/Bl2 pair).
+  kFixup2Bl1,        // Thumb2 Bl1 (start of Bl1/Bl2 pair).
   kFixupAdr,         // Adr.
   kFixupMovImmLST,   // kThumb2MovImm16LST.
   kFixupMovImmHST,   // kThumb2MovImm16HST.
   kFixupAlign4,      // Align to 4-byte boundary.
+  kFixupTrampCall,   // Call into trampoline for runtime helper.
 };
 
 std::ostream& operator<<(std::ostream& os, const FixupKind& kind);