X-Git-Url: http://drtracing.org/?a=blobdiff_plain;ds=sidebyside;f=gas%2Fdoc%2Fc-i386.texi;h=e0d0bc9f945f47aa3cb1ee30b061a6012620ed44;hb=5641ec015a191e0584fd4cae57bb3262f7a51735;hp=2cbffb98bae8e2ddd3de342a14f327962a81e033;hpb=33eaf5de31b248f84ae108cf0cf4e1664db9ee51;p=deliverable%2Fbinutils-gdb.git diff --git a/gas/doc/c-i386.texi b/gas/doc/c-i386.texi index 2cbffb98ba..e0d0bc9f94 100644 --- a/gas/doc/c-i386.texi +++ b/gas/doc/c-i386.texi @@ -1,4 +1,4 @@ -@c Copyright (C) 1991-2017 Free Software Foundation, Inc. +@c Copyright (C) 1991-2019 Free Software Foundation, Inc. @c This is part of the GAS manual. @c For copying conditions, see the file as.texinfo. @c man end @@ -74,7 +74,8 @@ usage and use x86-64 as target platform). @item -n By default, x86 GAS replaces multiple nop instructions used for alignment within code sections with multi-byte nop instructions such -as leal 0(%esi,1),%esi. This switch disables the optimization. +as leal 0(%esi,1),%esi. This switch disables the optimization if a single +byte nop (0x90) is explicitly specified as the fill byte for alignment. @cindex @samp{--divide} option, i386 @item --divide @@ -122,6 +123,7 @@ processor names are recognized: @code{bdver3}, @code{bdver4}, @code{znver1}, +@code{znver2}, @code{btver1}, @code{btver2}, @code{generic32} and @@ -139,6 +141,10 @@ accept various extension mnemonics. For example, @code{no287}, @code{no387}, @code{no687}, +@code{cmov}, +@code{nocmov}, +@code{fxsr}, +@code{nofxsr}, @code{mmx}, @code{nommx}, @code{sse}, @@ -167,10 +173,17 @@ accept various extension mnemonics. For example, @code{sha}, @code{rdpid}, @code{ptwrite}, +@code{cet}, +@code{gfni}, +@code{vaes}, +@code{vpclmulqdq}, @code{prefetchwt1}, @code{clflushopt}, @code{se1}, @code{clwb}, +@code{movdiri}, +@code{movdir64b}, +@code{enqcmd}, @code{avx512f}, @code{avx512cd}, @code{avx512er}, @@ -183,6 +196,10 @@ accept various extension mnemonics. For example, @code{avx512_4fmaps}, @code{avx512_4vnniw}, @code{avx512_vpopcntdq}, +@code{avx512_vbmi2}, +@code{avx512_vnni}, +@code{avx512_bitalg}, +@code{avx512_bf16}, @code{noavx512f}, @code{noavx512cd}, @code{noavx512er}, @@ -195,6 +212,12 @@ accept various extension mnemonics. For example, @code{noavx512_4fmaps}, @code{noavx512_4vnniw}, @code{noavx512_vpopcntdq}, +@code{noavx512_vbmi2}, +@code{noavx512_vnni}, +@code{noavx512_bitalg}, +@code{noavx512_vp2intersect}, +@code{noavx512_bf16}, +@code{noenqcmd}, @code{vmx}, @code{vmfunc}, @code{smx}, @@ -218,6 +241,10 @@ accept various extension mnemonics. For example, @code{clflush}, @code{mwaitx}, @code{clzero}, +@code{wbnoinvd}, +@code{pconfig}, +@code{waitpkg}, +@code{cldemote}, @code{lwp}, @code{fma4}, @code{xop}, @@ -276,6 +303,22 @@ AVX instructions with 128bit vector length, which is the default. @option{-mavxscalar=@var{256}} will encode scalar AVX instructions with 256bit vector length. +WARNING: Don't use this for production code - due to CPU errata the +resulting code may not work on certain models. + +@cindex @samp{-mvexwig=} option, i386 +@cindex @samp{-mvexwig=} option, x86-64 +@item -mvexwig=@var{0} +@itemx -mvexwig=@var{1} +These options control how the assembler should encode VEX.W-ignored (WIG) +VEX instructions. @option{-mvexwig=@var{0}} will encode WIG VEX +instructions with vex.w = 0, which is the default. +@option{-mvexwig=@var{1}} will encode WIG EVEX instructions with +vex.w = 1. + +WARNING: Don't use this for production code - due to CPU errata the +resulting code may not work on certain models. + @cindex @samp{-mevexlig=} option, i386 @cindex @samp{-mevexlig=} option, x86-64 @item -mevexlig=@var{128} @@ -378,6 +421,15 @@ R_X86_64_REX_GOTPCRELX, in 64-bit mode. relocations. The default can be controlled by a configure option @option{--enable-x86-relax-relocations}. +@cindex @samp{-mx86-used-note=} option, i386 +@cindex @samp{-mx86-used-note=} option, x86-64 +@item -mx86-used-note=@var{no} +@itemx -mx86-used-note=@var{yes} +These options control whether the assembler should generate +GNU_PROPERTY_X86_ISA_1_USED and GNU_PROPERTY_X86_FEATURE_2_USED +GNU property notes. The default can be controlled by the +@option{--enable-x86-used-note} configure option. + @cindex @samp{-mevexrcig=} option, i386 @cindex @samp{-mevexrcig=} option, x86-64 @item -mevexrcig=@var{rne} @@ -398,6 +450,40 @@ with 01, 10 and 11 RC bits, respectively. This option specifies that the assembler should accept only AMD64 or Intel64 ISA in 64-bit mode. The default is to accept both. +@cindex @samp{-O0} option, i386 +@cindex @samp{-O0} option, x86-64 +@cindex @samp{-O} option, i386 +@cindex @samp{-O} option, x86-64 +@cindex @samp{-O1} option, i386 +@cindex @samp{-O1} option, x86-64 +@cindex @samp{-O2} option, i386 +@cindex @samp{-O2} option, x86-64 +@cindex @samp{-Os} option, i386 +@cindex @samp{-Os} option, x86-64 +@item -O0 | -O | -O1 | -O2 | -Os +Optimize instruction encoding with smaller instruction size. @samp{-O} +and @samp{-O1} encode 64-bit register load instructions with 64-bit +immediate as 32-bit register load instructions with 31-bit or 32-bits +immediates, encode 64-bit register clearing instructions with 32-bit +register clearing instructions, encode 256-bit/512-bit VEX/EVEX vector +register clearing instructions with 128-bit VEX vector register +clearing instructions, encode 128-bit/256-bit EVEX vector +register load/store instructions with VEX vector register load/store +instructions, and encode 128-bit/256-bit EVEX packed integer logical +instructions with 128-bit/256-bit VEX packed integer logical. + +@samp{-O2} includes @samp{-O1} optimization plus encodes +256-bit/512-bit EVEX vector register clearing instructions with 128-bit +EVEX vector register clearing instructions. In 64-bit mode VEX encoded +instructions with commutative source operands will also have their +source operands swapped if this allows using the 2-byte VEX prefix form +instead of the 3-byte one. Certain forms of AND as well as OR with the +same (register) operand specified twice will also be changed to TEST. + +@samp{-Os} includes @samp{-O2} optimization plus encodes 16-bit, 32-bit +and 64-bit register tests with immediate as 8-bit register test with +immediate. @samp{-O0} turns off this optimization. + @end table @c man end @@ -420,8 +506,17 @@ specifies the desired alignment of the symbol in the bss section. This directive is only available for COFF based x86 targets. +@cindex @code{largecomm} directive, ELF +@item .largecomm @var{symbol} , @var{length}[, @var{alignment}] +This directive behaves in the same way as the @code{comm} directive +except that the data is placed into the @var{.lbss} section instead of +the @var{.bss} section @ref{Comm}. + +The directive is intended to be used for data which requires a large +amount of space, and it is only available for ELF based x86_64 +targets. + @c FIXME: Document other x86 specific directives ? Eg: .code16gcc, -@c .largecomm @end table @@ -503,11 +598,16 @@ instruction, do @emph{not} have reversed order. @ref{i386-Bugs}. In AT&T syntax the size of memory operands is determined from the last character of the instruction mnemonic. Mnemonic suffixes of @samp{b}, @samp{w}, @samp{l} and @samp{q} specify byte (8-bit), word (16-bit), long -(32-bit) and quadruple word (64-bit) memory references. Intel syntax accomplishes -this by prefixing memory operands (@emph{not} the instruction mnemonics) with -@samp{byte ptr}, @samp{word ptr}, @samp{dword ptr} and @samp{qword ptr}. Thus, -Intel @samp{mov al, byte ptr @var{foo}} is @samp{movb @var{foo}, %al} in AT&T -syntax. +(32-bit) and quadruple word (64-bit) memory references. Mnemonic suffixes +of @samp{x}, @samp{y} and @samp{z} specify xmm (128-bit vector), ymm +(256-bit vector) and zmm (512-bit vector) memory references, only when there's +no other way to disambiguate an instruction. Intel syntax accomplishes this by +prefixing memory operands (@emph{not} the instruction mnemonics) with +@samp{byte ptr}, @samp{word ptr}, @samp{dword ptr}, @samp{qword ptr}, +@samp{xmmword ptr}, @samp{ymmword ptr} and @samp{zmmword ptr}. Thus, Intel +syntax @samp{mov al, byte ptr @var{foo}} is @samp{movb @var{foo}, %al} in AT&T +syntax. In Intel syntax, @samp{fword ptr}, @samp{tbyte ptr} and +@samp{oword ptr} specify 48-bit, 80-bit and 128-bit memory references. In 64-bit code, @samp{movabs} can be used to encode the @samp{mov} instruction with the 64-bit displacement or immediate operand. @@ -547,7 +647,7 @@ line is treated as a comment, but in this case the line can also be a logical line number directive (@pxref{Comments}) or a preprocessor control command (@pxref{Preprocessing}). -If the @option{--divide} command line option has not been specified +If the @option{--divide} command-line option has not been specified then the @samp{/} character appearing anywhere on a line also introduces a line comment. @@ -597,10 +697,38 @@ quadruple word). @cindex encoding options, i386 @cindex encoding options, x86-64 -Different encoding options can be specified via optional mnemonic -suffix. @samp{.s} suffix swaps 2 register operands in encoding when -moving from one register to another. @samp{.d8} or @samp{.d32} suffix -prefers 8bit or 32bit displacement in encoding. +Different encoding options can be specified via pseudo prefixes: + +@itemize @bullet +@item +@samp{@{disp8@}} -- prefer 8-bit displacement. + +@item +@samp{@{disp32@}} -- prefer 32-bit displacement. + +@item +@samp{@{load@}} -- prefer load-form instruction. + +@item +@samp{@{store@}} -- prefer store-form instruction. + +@item +@samp{@{vex2@}} -- prefer 2-byte VEX prefix for VEX instruction. + +@item +@samp{@{vex3@}} -- prefer 3-byte VEX prefix for VEX instruction. + +@item +@samp{@{evex@}} -- encode with EVEX prefix. + +@item +@samp{@{rex@}} -- prefer REX prefix for integer and legacy vector +instructions (x86-64 only). Note that this differs from the @samp{rex} +prefix which generates REX prefix unconditionally. + +@item +@samp{@{nooptimize@}} -- disable instruction size optimization. +@end itemize @cindex conversion instructions, i386 @cindex i386 conversion instructions @@ -1179,12 +1307,13 @@ supported on the CPU specified. The choices for @var{cpu_type} are: @item @samp{i486} @tab @samp{i586} @tab @samp{i686} @tab @samp{pentium} @item @samp{pentiumpro} @tab @samp{pentiumii} @tab @samp{pentiumiii} @tab @samp{pentium4} @item @samp{prescott} @tab @samp{nocona} @tab @samp{core} @tab @samp{core2} -@item @samp{corei7} @tab @samp{l1om} @tab @samp{k1om} @samp{iamcu} +@item @samp{corei7} @tab @samp{l1om} @tab @samp{k1om} @tab @samp{iamcu} @item @samp{k6} @tab @samp{k6_2} @tab @samp{athlon} @tab @samp{k8} @item @samp{amdfam10} @tab @samp{bdver1} @tab @samp{bdver2} @tab @samp{bdver3} -@item @samp{bdver4} @tab @samp{znver1} @tab @samp{btver1} @tab @samp{btver2} -@item @samp{generic32} @tab @samp{generic64} -@item @samp{.mmx} @tab @samp{.sse} @tab @samp{.sse2} @tab @samp{.sse3} +@item @samp{bdver4} @tab @samp{znver1} @tab @samp{znver2} @tab @samp{btver1} +@item @samp{btver2} @tab @samp{generic32} @tab @samp{generic64} +@item @samp{.cmov} @tab @samp{.fxsr} @tab @samp{.mmx} +@item @samp{.sse} @tab @samp{.sse2} @tab @samp{.sse3} @item @samp{.ssse3} @tab @samp{.sse4.1} @tab @samp{.sse4.2} @tab @samp{.sse4} @item @samp{.avx} @tab @samp{.vmx} @tab @samp{.smx} @tab @samp{.ept} @item @samp{.clflush} @tab @samp{.movbe} @tab @samp{.xsave} @tab @samp{.xsaveopt} @@ -1197,7 +1326,12 @@ supported on the CPU specified. The choices for @var{cpu_type} are: @item @samp{.avx512f} @tab @samp{.avx512cd} @tab @samp{.avx512er} @tab @samp{.avx512pf} @item @samp{.avx512vl} @tab @samp{.avx512bw} @tab @samp{.avx512dq} @tab @samp{.avx512ifma} @item @samp{.avx512vbmi} @tab @samp{.avx512_4fmaps} @tab @samp{.avx512_4vnniw} -@item @samp{.avx512_vpopcntdq} @tab @samp{.clwb} @tab @samp{.rdpid} @tab @samp{.ptwrite} +@item @samp{.avx512_vpopcntdq} @tab @samp{.avx512_vbmi2} @tab @samp{.avx512_vnni} +@item @samp{.avx512_bitalg} @tab @samp{.avx512_bf16} @tab @samp{.avx512_vp2intersect} +@item @samp{.clwb} @tab @samp{.rdpid} @tab @samp{.ptwrite} @tab @item @samp{.ibt} +@item @samp{.wbnoinvd} @tab @samp{.pconfig} @tab @samp{.waitpkg} @tab @samp{.cldemote} +@item @samp{.shstk} @tab @samp{.gfni} @tab @samp{.vaes} @tab @samp{.vpclmulqdq} +@item @samp{.movdiri} @tab @samp{.movdir64b} @tab @samp{.enqcmd} @item @samp{.3dnow} @tab @samp{.3dnowa} @tab @samp{.sse4a} @tab @samp{.sse5} @item @samp{.syscall} @tab @samp{.rdtscp} @tab @samp{.svme} @tab @samp{.abm} @item @samp{.lwp} @tab @samp{.fma4} @tab @samp{.xop} @tab @samp{.cx16}