make/linux/makefiles/gcc.make

rev 2852 : 7116081: USE_PRECOMPILED_HEADER=0 triggers a single threaded build of the JVM
Summary: Changed the conditional to see if the precompiled header has been specified. Also, removed the unused PrecompiledOption.
Reviewed-by: TBD1, TBD2

*** 48,58 ****
  
  # check for precompiled headers support
  ifneq "$(shell expr \( $(CC_VER_MAJOR) \> 3 \) \| \( \( $(CC_VER_MAJOR) = 3 \) \& \( $(CC_VER_MINOR) \>= 4 \) \))" "0"
  # Allow the user to turn off precompiled headers from the command line.
  ifneq ($(USE_PRECOMPILED_HEADER),0)
- USE_PRECOMPILED_HEADER=1
  PRECOMPILED_HEADER_DIR=.
  PRECOMPILED_HEADER_SRC=$(GAMMADIR)/src/share/vm/precompiled/precompiled.hpp
  PRECOMPILED_HEADER=$(PRECOMPILED_HEADER_DIR)/precompiled.hpp.gch
  endif
  endif
--- 48,57 ----
*** 163,173 ****
  ifneq ("${CC_VER_MAJOR}", "2")
  DEPFLAGS = -MMD -MP -MF $(DEP_DIR)/$(@:%=%.d)
  endif
  
  # -DDONT_USE_PRECOMPILED_HEADER will exclude all includes in precompiled.hpp.
! ifneq ($(USE_PRECOMPILED_HEADER),1)
  CFLAGS += -DDONT_USE_PRECOMPILED_HEADER
  endif
  
  #------------------------------------------------------------------------
  # Linker flags
--- 162,172 ----
  ifneq ("${CC_VER_MAJOR}", "2")
  DEPFLAGS = -MMD -MP -MF $(DEP_DIR)/$(@:%=%.d)
  endif
  
  # -DDONT_USE_PRECOMPILED_HEADER will exclude all includes in precompiled.hpp.
! ifeq ($(USE_PRECOMPILED_HEADER),0)
  CFLAGS += -DDONT_USE_PRECOMPILED_HEADER
  endif
  
  #------------------------------------------------------------------------
  # Linker flags