34 lines
1.4 KiB
Plaintext
34 lines
1.4 KiB
Plaintext
# AX_MISALIGNED_ACCESS_FAILS(MACHINE, [ACTION-IF-MISALIGNED-FAILS], [ACTION-IF-MISALIGNED-OK])
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# -------------------------------------------------------------------------------------
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#
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# Check if a specified machine type cannot handle misaligned data. That is, multi-byte data
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# types which are not properly aligned in memory fail. Many machines are happy to work with
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# misaligned data, but slowing down a bit. Other machines just won't tolerate such data.
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#
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# This is a simple lookup amongst machines known to the current autotools. So far we only deal
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# with the ARM and sparc.
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# A lookup is used, as many of the devices which cannot handled misaligned access are embedded
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# processors, for which the code normally be cross-compiled.
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#
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AC_DEFUN([AX_MISALIGNED_ACCESS_FAILS],
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[AS_VAR_PUSHDEF([ac_MisalignedAccessFails], [ac_cv_misaligned_access_fails_$1])dnl
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AC_CACHE_CHECK([if $1 fails on misaligned memory access], ac_MisalignedAccessFails,
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[case $1 in
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arc | arm | arm[bl]e | arme[lb] | armv[2345] | armv[345][lb] \
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| bfin \
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| sparc \
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| xscale | xscalee[bl] \
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| arm-* | armbe-* | armle-* | armeb-* | armv*-* \
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| bfin-* \
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| sparc-* \
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| xscale-* | xscalee[bl]-* )
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AS_VAR_SET(ac_MisalignedAccessFails, yes)
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;;
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*)
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AS_VAR_SET(ac_MisalignedAccessFails, no)
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;;
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esac])
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AS_IF([test AS_VAR_GET(ac_MisalignedAccessFails) = yes], [$2], [$3])[]dnl
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AS_VAR_POPDEF([ac_MisalignedAccessFails])dnl
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])# MISALIGNED_ACCESS_FAILS
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