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diff --git a/gas/doc/c-tilepro.texi b/gas/doc/c-tilepro.texi new file mode 100644 index 0000000..bbccdfb --- /dev/null +++ b/gas/doc/c-tilepro.texi @@ -0,0 +1,297 @@ +@c Copyright 2011 +@c Free Software Foundation, Inc. +@c This is part of the GAS manual. +@c For copying conditions, see the file as.texinfo. +@ifset GENERIC +@page +@node TILEPro-Dependent +@chapter TILEPro Dependent Features +@end ifset +@ifclear GENERIC +@node Machine Dependencies +@chapter TILEPro Dependent Features +@end ifclear + +@cindex TILEPro support +@menu +* TILEPro Options:: TILEPro Options +* TILEPro Syntax:: TILEPro Syntax +* TILEPro Directives:: TILEPro Directives +@end menu + +@node TILEPro Options +@section Options + +@code{@value{AS}} has no machine-dependent command-line options for +TILEPro. + +@node TILEPro Syntax +@section Syntax +@cindex TILEPro syntax +@cindex syntax, TILEPro + +Block comments are delimited by @samp{/*} and @samp{*/}. End of line +comments may be introduced by @samp{#}. + +Instructions consist of a leading opcode or macro name followed by +whitespace and an optional comma-separated list of operands: + +@smallexample +@var{opcode} [@var{operand}, @dots{}] +@end smallexample + +Instructions must be separated by a newline or semicolon. + +There are two ways to write code: either write naked instructions, +which the assembler is free to combine into VLIW bundles, or specify +the VLIW bundles explicitly. + +Bundles are specified using curly braces: + +@smallexample +@{ @var{add} r3,r4,r5 ; @var{add} r7,r8,r9 ; @var{lw} r10,r11 @} +@end smallexample + +A bundle can span multiple lines. If you want to put multiple +instructions on a line, whether in a bundle or not, you need to +separate them with semicolons as in this example. + +A bundle may contain one or more instructions, up to the limit +specified by the ISA (currently three). If fewer instructions are +specified than the hardware supports in a bundle, the assembler +inserts @code{fnop} instructions automatically. + +The assembler will prefer to preserve the ordering of instructions +within the bundle, putting the first instruction in a lower-numbered +pipeline than the next one, etc. This fact, combined with the +optional use of explicit @code{fnop} or @code{nop} instructions, +allows precise control over which pipeline executes each instruction. + +If the instructions cannot be bundled in the listed order, the +assembler will automatically try to find a valid pipeline +assignment. If there is no way to bundle the instructions together, +the assembler reports an error. + +The assembler does not yet auto-bundle (automatically combine multiple +instructions into one bundle), but it reserves the right to do so in +the future. If you want to force an instruction to run by itself, put +it in a bundle explicitly with curly braces and use @code{nop} +instructions (not @code{fnop}) to fill the remaining pipeline slots in +that bundle. + +@menu +* TILEPro Opcodes:: Opcode Naming Conventions. +* TILEPro Registers:: Register Naming. +* TILEPro Modifiers:: Symbolic Operand Modifiers. +@end menu + +@node TILEPro Opcodes +@subsection Opcode Names +@cindex TILEPro opcode names +@cindex opcode names, TILEPro + +For a complete list of opcodes and descriptions of their semantics, +see @cite{TILE Processor User Architecture Manual}, available upon +request at www.tilera.com. + +@node TILEPro Registers +@subsection Register Names +@cindex TILEPro register names +@cindex register names, TILEPro + +General-purpose registers are represented by predefined symbols of the +form @samp{r@var{N}}, where @var{N} represents a number between +@code{0} and @code{63}. However, the following registers have +canonical names that must be used instead: + +@table @code +@item r54 +sp + +@item r55 +lr + +@item r56 +sn + +@item r57 +idn0 + +@item r58 +idn1 + +@item r59 +udn0 + +@item r60 +udn1 + +@item r61 +udn2 + +@item r62 +udn3 + +@item r63 +zero + +@end table + +The assembler will emit a warning if a numeric name is used instead of +the canonical name. The @code{.no_require_canonical_reg_names} +assembler pseudo-op turns off this +warning. @code{.require_canonical_reg_names} turns it back on. + +@node TILEPro Modifiers +@subsection Symbolic Operand Modifiers +@cindex TILEPro modifiers +@cindex symbol modifiers, TILEPro + +The assembler supports several modifiers when using symbol addresses +in TILEPro instruction operands. The general syntax is the following: + +@smallexample +modifier(symbol) +@end smallexample + +The following modifiers are supported: + +@table @code + +@item lo16 + +This modifier is used to load the low 16 bits of the symbol's address, +sign-extended to a 32-bit value (sign-extension allows it to be +range-checked against signed 16 bit immediate operands without +complaint). + +@item hi16 + +This modifier is used to load the high 16 bits of the symbol's +address, also sign-extended to a 32-bit value. + +@item ha16 + +@code{ha16(N)} is identical to @code{hi16(N)}, except if +@code{lo16(N)} is negative it adds one to the @code{hi16(N)} +value. This way @code{lo16} and @code{ha16} can be added to create any +32-bit value using @code{auli}. For example, here is how you move an +arbitrary 32-bit address into r3: + +@smallexample +moveli r3, lo16(sym) +auli r3, r3, ha16(sym) +@end smallexample + +@item got + +This modifier is used to load the offset of the GOT entry +corresponding to the symbol. + +@item got_lo16 + +This modifier is used to load the sign-extended low 16 bits of the +offset of the GOT entry corresponding to the symbol. + +@item got_hi16 + +This modifier is used to load the sign-extended high 16 bits of the +offset of the GOT entry corresponding to the symbol. + +@item got_ha16 + +This modifier is like @code{got_hi16}, but it adds one if +@code{got_lo16} of the input value is negative. + +@item plt + +This modifier is used for function symbols. It causes a +@emph{procedure linkage table}, an array of code stubs, to be created +at the time the shared object is created or linked against, together +with a global offset table entry. The value is a pc-relative offset +to the corresponding stub code in the procedure linkage table. This +arrangement causes the run-time symbol resolver to be called to look +up and set the value of the symbol the first time the function is +called (at latest; depending environment variables). It is only safe +to leave the symbol unresolved this way if all references are function +calls. + +@item tls_gd + +This modifier is used to load the offset of the GOT entry of the +symbol's TLS descriptor, to be used for general-dynamic TLS accesses. + +@item tls_gd_lo16 + +This modifier is used to load the sign-extended low 16 bits of the +offset of the GOT entry of the symbol's TLS descriptor, to be used for +general dynamic TLS accesses. + +@item tls_gd_hi16 + +This modifier is used to load the sign-extended high 16 bits of the +offset of the GOT entry of the symbol's TLS descriptor, to be used for +general dynamic TLS accesses. + +@item tls_gd_ha16 + +This modifier is like @code{tls_gd_hi16}, but it adds one to the value +if @code{tls_gd_lo16} of the input value is negative. + +@item tls_ie + +This modifier is used to load the offset of the GOT entry containing +the offset of the symbol's address from the TCB, to be used for +initial-exec TLS accesses. + +@item tls_ie_lo16 + +This modifier is used to load the low 16 bits of the offset of the GOT +entry containing the offset of the symbol's address from the TCB, to +be used for initial-exec TLS accesses. + +@item tls_ie_hi16 + +This modifier is used to load the high 16 bits of the offset of the +GOT entry containing the offset of the symbol's address from the TCB, +to be used for initial-exec TLS accesses. + +@item tls_ie_ha16 + +This modifier is like @code{tls_ie_hi16}, but it adds one to the value +if @code{tls_ie_lo16} of the input value is negative. + +@end table + +@node TILEPro Directives +@section TILEPro Directives +@cindex machine directives, TILEPro +@cindex TILEPro machine directives + +@table @code + +@cindex @code{.align} directive, TILEPro +@item .align @var{expression} [, @var{expression}] +This is the generic @var{.align} directive. The first argument is the +requested alignment in bytes. + +@cindex @code{.allow_suspicious_bundles} directive, TILEPro +@item .allow_suspicious_bundles +Turns on error checking for combinations of instructions in a bundle +that probably indicate a programming error. This is on by default. + +@item .no_allow_suspicious_bundles +Turns off error checking for combinations of instructions in a bundle +that probably indicate a programming error. + +@cindex @code{.require_canonical_reg_names} directive, TILEPro +@item .require_canonical_reg_names +Require that canonical register names be used, and emit a warning if +the numeric names are used. This is on by default. + +@item .no_require_canonical_reg_names +Permit the use of numeric names for registers that have canonical +names. + +@end table + |