Parallelize byte compilation on MS-Windows.

 lisp/makefile.w32-in (WINS_BASIC1, WINS_BASIC2, WINS_BASIC3)
 (WINS_BASIC4): New variables, subdivide subdirectories into 4
 parts.
 (WINS_BASIC): Define as concatenation of the above.
 (compile): Subdivide into 4 separate and independent jobs that can
 be run in parallel.
 (compile0-CMD, compile0-SH): New targets for compiling
 COMPILE_FIRST files, which are prerequisites for the rest of the
 byte-compilation.
 (compile1-CMD, compile2-CMD, compile3-CMD, compile4-CMD): New
 targets for parallel compilation with cmd.exe.
 (compile1-SH, compile2-SH, compile3-SH, compile4-SH): Ditto for
 compiling under a Unixy shell.

2 files changed, 90 insertions, 12 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index e7d8f0652cc..5dba3964f1c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,20 @@
+2012-12-09  Eli Zaretskii  <eliz@gnu.org>
+
+        Parallelize byte compilation on MS-Windows.
+        * makefile.w32-in (WINS_BASIC1, WINS_BASIC2, WINS_BASIC3)
+        (WINS_BASIC4): New variables, subdivide subdirectories into 4
+        parts.
+        (WINS_BASIC): Define as concatenation of the above.
+        (compile): Subdivide into 4 separate and independent jobs that can
+        be run in parallel.
+        (compile0-CMD, compile0-SH): New targets for compiling
+        COMPILE_FIRST files, which are prerequisites for the rest of the
+        byte-compilation.
+        (compile1-CMD, compile2-CMD, compile3-CMD, compile4-CMD): New
+        targets for parallel compilation with cmd.exe.
+        (compile1-SH, compile2-SH, compile3-SH, compile4-SH): Ditto for
+        compiling under a Unixy shell.
+
 2012-12-09  Chong Yidong  <cyd@gnu.org>
 
         * simple.el (set-mark-default-inactive): Delete this
diff --git a/lisp/makefile.w32-in b/lisp/makefile.w32-in
index 9f1b57e85b1..cb2cba466f6 100644
--- a/lisp/makefile.w32-in
+++ b/lisp/makefile.w32-in
@@ -104,27 +104,39 @@ WINS_CEDET=\
         cedet/semantic/symref \
         cedet/semantic/wisent
 
-WINS_BASIC=\
+# The list of subdirectories is subdivided into 4 more or less equal
+# parts so that we could have 4-way parallelism while compiling Lisp
+# files, which helps to slash bootstrap times.  See the 'compile'
+# target below.
+WINS_BASIC1=\
         calc \
         calendar \
         emacs-lisp \
-        emulation \
         erc \
-        eshell \
+        net \
+        url
+
+WINS_BASIC2=\
         gnus \
         international \
         language \
-        mail \
+        mail
+
+WINS_BASIC3=\
+        emulation \
         mh-e \
-        net \
         nxml \
         org \
         play \
-        progmodes \
         textmodes \
-        url \
         vc
 
+WINS_BASIC4=\
+        eshell \
+        progmodes
+
+WINS_BASIC= $(WINS_BASIC1) $(WINS_BASIC2) $(WINS_BASIC3) $(WINS_BASIC4)
+
 # Directories with lisp files to compile, and to extract data from
 # (customs, autoloads, etc.)
 WINS_UPDATES=$(WINS_BASIC) \
@@ -311,22 +323,71 @@ TAGS-LISP-CMD: $(lisptagsfiles1) $(lisptagsfiles2) $(lisptagsfiles3) $(lisptagsf
 # compiled find the right files.
 
 # Need separate version for sh and native cmd.exe
-compile: $(lisp)/subdirs.el compile-$(SHELLTYPE) doit
+compile: $(lisp)/subdirs.el compile0-$(SHELLTYPE) compile1-$(SHELLTYPE) compile2-$(SHELLTYPE) compile3-$(SHELLTYPE) compile4-$(SHELLTYPE) doit
 
-compile-CMD: autoloads
+compile0-CMD: autoloads
 #       -for %%f in ($(lisp) $(WINS)) do for %%g in (%%f\*.elc) do @attrib -r %%g
         for %%f in ($(COMPILE_FIRST)) do \
           $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done %%f
-        for %%f in (. $(WINS)) do for %%g in (%%f/*.el) do \
+
+compile1-CMD: autoloads compile0-CMD
+        for %%f in (. $(WINS_BASIC1)) do for %%g in (%%f/*.el) do \
           $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done %%f/%%g
 
-compile-SH: autoloads
+compile2-CMD: autoloads compile0-CMD
+        for %%f in ($(WINS_BASIC2)) do for %%g in (%%f/*.el) do \
+          $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done %%f/%%g
+
+compile3-CMD: autoloads compile0-CMD
+        for %%f in ($(WINS_BASIC3)) do for %%g in (%%f/*.el) do \
+          $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done %%f/%%g
+
+compile4-CMD: autoloads compile0-CMD
+        for %%f in ($(WINS_BASIC4) $(WINS_CEDET) term obsolete) do for %%g in (%%f/*.el) do \
+          $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done %%f/%%g
+
+compile0-SH: autoloads
 #       for elc in $(lisp)/*.elc $(lisp)/*/*.elc; do attrib -r $$elc; done
         for el in $(COMPILE_FIRST); do \
           echo Compiling $$el; \
           $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done $$el; \
         done
-        for dir in $(lisp) $(WINS); do \
+
+compile1-SH: autoloads compile0-SH
+        for dir in $(lisp) $(WINS_BASIC1); do \
+          for el in $$dir/*.el; do \
+            if test -f $$el; \
+            then \
+              echo Compiling $$el; \
+              $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done $$el; \
+            fi \
+          done; \
+        done
+
+compile2-SH: autoloads compile0-SH
+        for dir in $(WINS_BASIC2); do \
+          for el in $$dir/*.el; do \
+            if test -f $$el; \
+            then \
+              echo Compiling $$el; \
+              $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done $$el; \
+            fi \
+          done; \
+        done
+
+compile3-SH: autoloads compile0-SH
+        for dir in $(WINS_BASIC3); do \
+          for el in $$dir/*.el; do \
+            if test -f $$el; \
+            then \
+              echo Compiling $$el; \
+              $(emacs) -l loaddefs $(BYTE_COMPILE_FLAGS) -f batch-byte-compile-if-not-done $$el; \
+            fi \
+          done; \
+        done
+
+compile4-SH: autoloads compile0-SH
+        for dir in $(WINS_BASIC4) $(WINS_CEDET) terms obsolete; do \
           for el in $$dir/*.el; do \
             if test -f $$el; \
             then \