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nosplit: Limit the effect of NOSPLIT

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[nosplit eax+eax] was encoded [eax*2] previously but
this seems against the user's intention.
So in this case, nosplit is ignored now and [eax+eax] will be
generated.
Document is also updated accordingly.

Signed-off-by: Jin Kyu Song <jin.kyu.song@intel.com>
This commit is contained in:
Jin Kyu Song
2013-12-18 21:28:41 -08:00
parent 97f6faec62
commit 3d06af2bd9
2 changed files with 5 additions and 3 deletions
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2
assemble.c
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@@ -2629,7 +2629,7 @@ static enum ea_type process_ea(operand *input, ea *output, int bits,
} }
} else { } else {
if (((s == 2 && it != REG_NUM_ESP && if (((s == 2 && it != REG_NUM_ESP &&
!(eaflags & EAF_TIMESTWO)) || (!(eaflags & EAF_TIMESTWO) || (ht == EAH_SUMMED))) ||
s == 3 || s == 5 || s == 9) && bt == -1) { s == 3 || s == 5 || s == 9) && bt == -1) {
/* convert 3*EAX to EAX+2*EAX */ /* convert 3*EAX to EAX+2*EAX */
bt = it, bx = ix, s--; bt = it, bx = ix, s--;

6
doc/nasmdoc.src
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@@ -1460,6 +1460,8 @@ fact, it will also split \c{[eax*2+offset]} into
\c{[eax+eax+offset]}. You can combat this behaviour by the use of \c{[eax+eax+offset]}. You can combat this behaviour by the use of
the \c{NOSPLIT} keyword: \c{[nosplit eax*2]} will force the \c{NOSPLIT} keyword: \c{[nosplit eax*2]} will force
\c{[eax*2+0]} to be generated literally. \c{[eax*2+0]} to be generated literally.
However, \c{NOSPLIT} in \c{[nosplit eax+eax]} will be ignored because user's
intention here is considered as \c{[eax+eax]}.
In 64-bit mode, NASM will by default generate absolute addresses. The In 64-bit mode, NASM will by default generate absolute addresses. The
\i\c{REL} keyword makes it produce \c{RIP}-relative addresses. Since \i\c{REL} keyword makes it produce \c{RIP}-relative addresses. Since
@@ -4465,8 +4467,8 @@ be used.
\c call foo ; BND will be prefixed \c call foo ; BND will be prefixed
\c nobnd call foo ; BND will NOT be prefixed \c nobnd call foo ; BND will NOT be prefixed
DEFAULT NOBND can disable DEFAULT BND and then \c{BND} prefix will be added \c{DEFAULT NOBND} can disable \c{DEFAULT BND} and then \c{BND} prefix will be
only when explicitly specified in code. added only when explicitly specified in code.
\H{section} \i\c{SECTION} or \i\c{SEGMENT}: Changing and \i{Defining \H{section} \i\c{SECTION} or \i\c{SEGMENT}: Changing and \i{Defining
Sections} Sections}