aarch64-linux-gnu-4.9/share/doc/as.html/ESA_002f390-Syntax.html - toolchains/linux-x86/gcc - Git at Google

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 <a name="ESA_002f390-Syntax"></a>
 <div class="header">
 <p>
 Next: <a href="ESA_002f390-Floating-Point.html#ESA_002f390-Floating-Point" accesskey="n" rel="next">ESA/390 Floating Point</a>, Previous: <a href="ESA_002f390-Options.html#ESA_002f390-Options" accesskey="p" rel="prev">ESA/390 Options</a>, Up: <a href="ESA_002f390_002dDependent.html#ESA_002f390_002dDependent" accesskey="u" rel="up">ESA/390-Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
 </div>
 <hr>
 <a name="Syntax-13"></a>
 <h4 class="subsection">9.14.3 Syntax</h4>
 <p>The opcode/operand syntax follows the ESA/390 Principles of Operation
 manual; assembler directives and general syntax are loosely based on the
 prevailing AT&amp;T/SVR4/ELF/Solaris style notation.  HLASM-style directives
 are <em>not</em> supported for the most part, with the exception of those
 described herein.
 </p>
 <p>A leading dot in front of directives is optional, and the case of
 directives is ignored; thus for example, .using and USING have the same
 effect.
 </p>
 <p>A colon may immediately follow a label definition.  This is
 simply for compatibility with how most assembly language programmers
 write code.
 </p>
 <p>&lsquo;<samp>#</samp>&rsquo; is the line comment character.
 </p>
 <p>&lsquo;<samp>;</samp>&rsquo; can be used instead of a newline to separate statements.
 </p>
 <p>Since &lsquo;<samp>$</samp>&rsquo; has no special meaning, you may use it in symbol names.
 </p>
 <p>Registers can be given the symbolic names r0..r15, fp0, fp2, fp4, fp6.
 By using thesse symbolic names, <code>as</code> can detect simple
 syntax errors. The name rarg or r.arg is a synonym for r11, rtca or r.tca
 for r12, sp, r.sp, dsa r.dsa for r13, lr or r.lr for r14, rbase or r.base
 for r3 and rpgt or r.pgt for r4.
 </p>
 <p>&lsquo;<samp>*</samp>&rsquo; is the current location counter.  Unlike &lsquo;<samp>.</samp>&rsquo; it is always
 relative to the last USING directive.  Note that this means that
 expressions cannot use multiplication, as any occurrence of &lsquo;<samp>*</samp>&rsquo;
 will be interpreted as a location counter.
 </p>
 <p>All labels are relative to the last USING.  Thus, branches to a label
 always imply the use of base+displacement.
 </p>
 <p>Many of the usual forms of address constants / address literals
 are supported.  Thus,
 </p><div class="example">
 <pre class="example">	.using	*,r3
 	L	r15,=A(some_routine)
 	LM	r6,r7,=V(some_longlong_extern)
 	A	r1,=F'12'
 	AH	r0,=H'42'
 	ME	r6,=E'3.1416'
 	MD	r6,=D'3.14159265358979'
 	O	r6,=XL4'cacad0d0'
 	.ltorg
 </pre></div>
 <p>should all behave as expected: that is, an entry in the literal
 pool will be created (or reused if it already exists), and the
 instruction operands will be the displacement into the literal pool
 using the current base register (as last declared with the <code>.using</code>
 directive).
 </p>
 <hr>
 <div class="header">
 <p>
 Next: <a href="ESA_002f390-Floating-Point.html#ESA_002f390-Floating-Point" accesskey="n" rel="next">ESA/390 Floating Point</a>, Previous: <a href="ESA_002f390-Options.html#ESA_002f390-Options" accesskey="p" rel="prev">ESA/390 Options</a>, Up: <a href="ESA_002f390_002dDependent.html#ESA_002f390_002dDependent" accesskey="u" rel="up">ESA/390-Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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	<a name="ESA_002f390-Syntax"></a>
	<div class="header">
	<p>
	Next: <a href="ESA_002f390-Floating-Point.html#ESA_002f390-Floating-Point" accesskey="n" rel="next">ESA/390 Floating Point</a>, Previous: <a href="ESA_002f390-Options.html#ESA_002f390-Options" accesskey="p" rel="prev">ESA/390 Options</a>, Up: <a href="ESA_002f390_002dDependent.html#ESA_002f390_002dDependent" accesskey="u" rel="up">ESA/390-Dependent</a>   [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
	</div>
	<hr>
	<a name="Syntax-13"></a>
	<h4 class="subsection">9.14.3 Syntax</h4>
	<p>The opcode/operand syntax follows the ESA/390 Principles of Operation
	manual; assembler directives and general syntax are loosely based on the
	prevailing AT&T/SVR4/ELF/Solaris style notation. HLASM-style directives
	are <em>not</em> supported for the most part, with the exception of those
	described herein.
	</p>
	<p>A leading dot in front of directives is optional, and the case of
	directives is ignored; thus for example, .using and USING have the same
	effect.
	</p>
	<p>A colon may immediately follow a label definition. This is
	simply for compatibility with how most assembly language programmers
	write code.
	</p>
	<p>‘<samp>#</samp>’ is the line comment character.
	</p>
	<p>‘<samp>;</samp>’ can be used instead of a newline to separate statements.
	</p>
	<p>Since ‘<samp>$</samp>’ has no special meaning, you may use it in symbol names.
	</p>
	<p>Registers can be given the symbolic names r0..r15, fp0, fp2, fp4, fp6.
	By using thesse symbolic names, <code>as</code> can detect simple
	syntax errors. The name rarg or r.arg is a synonym for r11, rtca or r.tca
	for r12, sp, r.sp, dsa r.dsa for r13, lr or r.lr for r14, rbase or r.base
	for r3 and rpgt or r.pgt for r4.
	</p>
	<p>‘<samp>*</samp>’ is the current location counter. Unlike ‘<samp>.</samp>’ it is always
	relative to the last USING directive. Note that this means that
	expressions cannot use multiplication, as any occurrence of ‘<samp>*</samp>’
	will be interpreted as a location counter.
	</p>
	<p>All labels are relative to the last USING. Thus, branches to a label
	always imply the use of base+displacement.
	</p>
	<p>Many of the usual forms of address constants / address literals
	are supported. Thus,
	</p><div class="example">
	<pre class="example"> .using *,r3
	L r15,=A(some_routine)
	LM r6,r7,=V(some_longlong_extern)
	A r1,=F'12'
	AH r0,=H'42'
	ME r6,=E'3.1416'
	MD r6,=D'3.14159265358979'
	O r6,=XL4'cacad0d0'
	.ltorg
	</pre></div>
	<p>should all behave as expected: that is, an entry in the literal
	pool will be created (or reused if it already exists), and the
	instruction operands will be the displacement into the literal pool
	using the current base register (as last declared with the <code>.using</code>
	directive).
	</p>
	<hr>
	<div class="header">
	<p>
	Next: <a href="ESA_002f390-Floating-Point.html#ESA_002f390-Floating-Point" accesskey="n" rel="next">ESA/390 Floating Point</a>, Previous: <a href="ESA_002f390-Options.html#ESA_002f390-Options" accesskey="p" rel="prev">ESA/390 Options</a>, Up: <a href="ESA_002f390_002dDependent.html#ESA_002f390_002dDependent" accesskey="u" rel="up">ESA/390-Dependent</a>   [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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