Compile x86 and x86-64 SIMD optimizations

Change-Id: I2aa903ea44cc3da9255543dd21a312e3dd410b8c

1 files changed, 38 insertions, 0 deletions

diff --git a/README.android b/README.android
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+Any Android specific modifications to upstream libjpeg-turbo (1.4.2) should
+be listed here:
+
+(1) jconfig.h and jconfigint.h
+
+These are included upstream as jconfig.h.in and jconfigint.h.in.
+We have the option autogenerate these platform/version specific files (using
+the libjpeg-turbo build system) or to manually create them.
+
+Autogenerating these files on linux gets us most of the way, but we've needed
+to add some multi-platform flexibility to the INLINE and SIZEOF_SIZE_T macros.
+
+(2) Partial decoding optimizations
+
+These have been cherry picked from upstream and will be included in the 1.5
+release.  The cherry picked commits are:
+90c92ed5bf98bda381fcc369f0da46837dbb8894
+fc235cfdabbcd1c915fa3a87a56d73727da2eaeb
+9bafc6a7ffa62ed7109314cbb66085075cd1c334
+3fb56e969c890e6aa7b044eea7e24751ab6f4e97
+e67a7e37deb26db5ac7da420560d22e1ca7ea4b4
+f8a1775eab51fb0a83e82343d2eae8cf52b16124
+15884f48eb1a4acd9c6c24291db974c596e71934
+ac30a1bf12751bd82e56158eb9456a28d9c086f3
+
+(3) simd/jsimdext.inc
+
+The modification enables us to compile x86 SIMD.
+
+The original code was:
+%define EXTN(name)   _ %+ name
+The new code is:
+%define EXTN(name)   name
+
+It is unclear why the unmodified code from upstream appends an underscore
+to name.  Before removing the underscore, the code failed to link because
+the function names in the SIMD code did not match the callers (because of
+the extra underscore).