Added IBM Cell SDK 2.x software_cache to Bullet/Extras. There is an option to enable it for the BulletMultiThreaded Cell version.

See USE_SOFTWARE_CACHE in Bullet\src\BulletMultiThreaded\SpuNarrowPhaseCollisionTask\SpuGatheringCollisionTask.cpp
It improves the Bullet midphase collision detection (triangle/vertex fetch)
The license is CommonPublicLicense-1.0, see included license docs.

Extras/software_cache/hello.spu.mk

@@ -0,0 +1,19 @@
+#   SCE CONFIDENTIAL                                      
+#   PLAYSTATION(R)3 Programmer Tool Runtime Library 085.007
+#   Copyright (C) 2005 Sony Computer Entertainment Inc.   
+#   All Rights Reserved.                                  
+#
+
+CELL_MK_DIR ?= $(CELL_SDK)/samples/mk
+
+
+include $(CELL_MK_DIR)/sdk.makedef.mk 
+
+SPU_INCDIRS += -Icache/include
+SPU_SRCS     = hello.spu.c
+SPU_TARGET   = hello.spu.elf
+SPU_OPTIMIZE_LV=-O0
+
+include $(CELL_MK_DIR)/sdk.target.mk
+
+