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

@@ -48,11 +48,10 @@
 
 # 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

@@ -163,11 +162,11 @@
 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 ($(USE_PRECOMPILED_HEADER),1)
+ifeq ($(USE_PRECOMPILED_HEADER),0)
 CFLAGS += -DDONT_USE_PRECOMPILED_HEADER
 endif
 
 #------------------------------------------------------------------------
 # Linker flags