Speed up ARMv7 support.

When building for ARMv7 with thumb2 instructions, the optimized
`FT_MulFix_arm' assembly routine was not being used.

The reason for this is in the `ftconfig.h' header, namely:

- The assembly routine uses the `smull' instruction which is not
  available when generating Thumb-1 machine code.  It is available
  in Thumb-2 mode, though.

- The header was written a long time ago before Thumb-2 became
  widely popular (e.g. with Android).  So it simply doesn't use the
  assembly routine if the `__thumb__' built-in macro is defined.

- When compiling in Thumb-2 mode, the compiler will define both
  `__thumb__' and `__thumb2__'.

By checking for `(__thumb2__ || !__thumb__)', we ensure that the
assembly routine is only avoided when generating Thumb-1 code.

Given that this is performance-sensitive function, this improves
`ftbench' as follows on a Galaxy Nexus:

                           Before (us/op)   After (us/op)

  - loading Arial.ttf glyphs at 14 ppem [1]

      Load                   34.285          33.098

  - same operation with the light auto-hinter [2]

      Load                   31.317          29.590

  - same operation without hinting [3]

      Load                    6.143           5.376

  - loading Arial.ttf advances at 14 ppem [4]

      Load_Advances (normal) 34.216          33.016
      Load_Advances (fast)    0.176           0.176

  [1] ftbench -t 5 -p -s 14 -b a -f 0008 Arial.ttf
  [2] ftbench -t 5 -p -s 14 -b a -r 1 -f 0028 Arial.ttf
  [3] ftbench -t 5 -p -s 14 -b a -f 000a Arial.ttf
  [4] ftbench -t 5 -p -s 14 -b b -f 0008 Arial.ttf

* builds/unix/ftconfig.in, include/freetype/config/ftconfig.h
(FT_MULFIX_ASSEMBLER): Fix handling for ARMv7.

ChangeLog

@@ -1,3 +1,56 @@
+2013-07-16  David Turner  <digit@google.com>
+
+	Speed up ARMv7 support.
+
+	When building for ARMv7 with thumb2 instructions, the optimized
+	`FT_MulFix_arm' assembly routine was not being used.
+
+	The reason for this is in the `ftconfig.h' header, namely:
+
+	- The assembly routine uses the `smull' instruction which is not
+	  available when generating Thumb-1 machine code.  It is available
+	  in Thumb-2 mode, though.
+
+	- The header was written a long time ago before Thumb-2 became
+	  widely popular (e.g. with Android).  So it simply doesn't use the
+	  assembly routine if the `__thumb__' built-in macro is defined.
+
+	- When compiling in Thumb-2 mode, the compiler will define both
+	  `__thumb__' and `__thumb2__'.
+
+	By checking for `(__thumb2__ || !__thumb__)', we ensure that the
+	assembly routine is only avoided when generating Thumb-1 code.
+
+	Given that this is performance-sensitive function, this improves
+	`ftbench' as follows on a Galaxy Nexus:
+
+	                           Before (us/op)   After (us/op)
+
+	  - loading Arial.ttf glyphs at 14 ppem [1]
+
+	      Load                   34.285          33.098
+
+	  - same operation with the light auto-hinter [2]
+
+	      Load                   31.317          29.590
+
+	  - same operation without hinting [3]
+
+	      Load                    6.143           5.376
+
+	  - loading Arial.ttf advances at 14 ppem [4]
+
+	      Load_Advances (normal) 34.216          33.016
+	      Load_Advances (fast)    0.176           0.176
+
+	  [1] ftbench -t 5 -p -s 14 -b a -f 0008 Arial.ttf
+	  [2] ftbench -t 5 -p -s 14 -b a -r 1 -f 0028 Arial.ttf
+	  [3] ftbench -t 5 -p -s 14 -b a -f 000a Arial.ttf
+	  [4] ftbench -t 5 -p -s 14 -b b -f 0008 Arial.ttf
+
+	* builds/unix/ftconfig.in, include/freetype/config/ftconfig.h
+	(FT_MULFIX_ASSEMBLER): Fix handling for ARMv7.
+
 2013-06-28  Werner Lemberg  <wl@gnu.org>
 
 	* docs/CHANGES: Updated.

builds/unix/ftconfig.in

@@ -395,8 +395,10 @@ FT_BEGIN_HEADER
 
 #ifdef __GNUC__
 
-#if defined( __arm__ ) && !defined( __thumb__ )    && \
+#if defined( __arm__ )                                 && \
+    ( defined( __thumb2__ ) || !defined( __thumb__ ) ) && \
     !( defined( __CC_ARM ) || defined( __ARMCC__ ) )
+
 #define FT_MULFIX_ASSEMBLER  FT_MulFix_arm
 
   /* documentation is in freetype.h */
@@ -422,7 +424,9 @@ FT_BEGIN_HEADER
     return a;
   }
 
-#endif /* __arm__ && !__thumb__ && !( __CC_ARM || __ARMCC__ ) */
+#endif /* __arm__                      && */
+       /* ( __thumb2__ || !__thumb__ ) && */
+       /* !( __CC_ARM || __ARMCC__ )      */
 
 #if defined( __i386__ )
 #define FT_MULFIX_ASSEMBLER  FT_MulFix_i386

include/freetype/config/ftconfig.h

@@ -367,7 +367,8 @@ FT_BEGIN_HEADER
 
 #ifdef __GNUC__
 
-#if defined( __arm__ ) && !defined( __thumb__ )    && \
+#if defined( __arm__ )                                 && \
+    ( !defined( __thumb__ ) || defined( __thumb2__ ) ) && \
     !( defined( __CC_ARM ) || defined( __ARMCC__ ) )
 #define FT_MULFIX_ASSEMBLER  FT_MulFix_arm
 
@@ -394,7 +395,9 @@ FT_BEGIN_HEADER
     return a;
   }
 
-#endif /* __arm__ && !__thumb__ && !( __CC_ARM || __ARMCC__ ) */
+#endif /* __arm__                      && */
+       /* ( __thumb2__ || !__thumb__ ) && */
+       /* !( __CC_ARM || __ARMCC__ )      */
 
 #if defined( __i386__ )
 #define FT_MULFIX_ASSEMBLER  FT_MulFix_i386