Clean up code to build under GCC7, fix pgm_read_unaligned #6270
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Apply most compatible changes needed to get the core compiling under GCC 7.2 to the main gcc 4.8 tree to ease porting for 3.0.0. Update pgmspace.h with corrected and optimized unaligned pgm_read macros. Now pgm_read_dword in the unaligned case gives proper results even if optimization is enabled and is also written in assembly and only 1 instruction longer than the pgm_read_byte macro (which also has been optimized to reduce 1 instruction). These changes should marginally shrink code and speed up flash reads accordingly. The toolchain should/will be rebuilt at a later time with this optimization to ensure it's used in the libc.a/etc. files.
devyte
requested changes
Jul 8, 2019
devyte
approved these changes
Jul 8, 2019
d-a-v
approved these changes
Jul 8, 2019
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Apply most compatible changes needed to get the core compiling under GCC
7.2 to the main gcc 4.8 tree to ease porting for 3.0.0.
Update pgmspace.h with corrected and optimized unaligned pgm_read
macros. Now pgm_read_dword in the unaligned case gives proper results
even if optimization is enabled and is also written in assembly and only
1 instruction longer than the pgm_read_byte macro (which also has been
optimized to reduce 1 instruction). These changes should marginally
shrink code and speed up flash reads accordingly.
The toolchain should/will be rebuilt at a later time with this
optimization to ensure it's used in the libc.a/etc. files.