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docs: Add __GIMPLE and __RTL to the "Internals" doc

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gcc/ChangeLog:
	* doc/sourcebuild.texi (Testsuites): Add "GIMPLE Tests" and
	"RTL Tests" to menu.
	(GIMPLE Tests): New node.
	(RTL Tests): New node.

From-SVN: r244977
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David Malcolm 2017-01-27 14:25:59 +00:00 • committed by David Malcolm
parent 40b6bff965
commit 71103b6104
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gcc/ChangeLog
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@ -1,3 +1,10 @@
2017-01-27 David Malcolm <dmalcolm@redhat.com>
* doc/sourcebuild.texi (Testsuites): Add "GIMPLE Tests" and
"RTL Tests" to menu.
(GIMPLE Tests): New node.
(RTL Tests): New node.
2017-01-27 Richard Biener <rguenther@suse.de>
PR tree-optimization/79245

93
gcc/doc/sourcebuild.texi
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@ -863,6 +863,8 @@ here; FIXME: document the others.
* profopt Testing:: Support for testing profile-directed optimizations.
* compat Testing:: Support for testing binary compatibility.
* Torture Tests:: Support for torture testing using multiple options.
* GIMPLE Tests:: Support for testing GIMPLE passes.
* RTL Tests:: Support for testing RTL passes.
@end menu
@node Test Idioms
@ -2931,3 +2933,94 @@ set ADDITIONAL_TORTURE_OPTIONS [list \
@{ -O2 -ftree-loop-linear @} \
@{ -O2 -fpeel-loops @} ]
@end smallexample
@node GIMPLE Tests
@section Support for testing GIMPLE passes
As of gcc 7, C functions can be tagged with @code{__GIMPLE} to indicate
that the function body will be GIMPLE, rather than C. The compiler requires
the option @option{-fgimple} to enable this functionality. For example:
@smallexample
/* @{ dg-do compile @} */
/* @{ dg-options "-O -fgimple" @} */
void __GIMPLE (startwith ("dse2")) foo ()
@{
int a;
bb_2:
if (a > 4)
goto bb_3;
else
goto bb_4;
bb_3:
a_2 = 10;
goto bb_5;
bb_4:
a_3 = 20;
bb_5:
a_1 = __PHI (bb_3: a_2, bb_4: a_3);
a_4 = a_1 + 4;
return;
@}
@end smallexample
The @code{startwith} argument indicates at which pass to begin.
Use the dump modifier @code{-gimple} (e.g. @option{-fdump-tree-all-gimple})
to make tree dumps more closely follow the format accepted by the GIMPLE
parser.
Example DejaGnu tests of GIMPLE can be seen in the source tree at
@file{gcc/testsuite/gcc.dg/gimplefe-*.c}.
The @code{__GIMPLE} parser is integrated with the C tokenizer and
preprocessor, so it should be possible to use macros to build out
test coverage.
@node RTL Tests
@section Support for testing RTL passes
As of gcc 7, C functions can be tagged with @code{__RTL} to indicate that the
function body will be RTL, rather than C. For example:
@smallexample
double __RTL (startwith ("ira")) test (struct foo *f, const struct bar *b)
@{
(function "test"
[...snip; various directives go in here...]
) ;; function "test"
@}
@end smallexample
The @code{startwith} argument indicates at which pass to begin.
The parser expects the RTL body to be in the format emitted by this
dumping function:
@smallexample
DEBUG_FUNCTION void
print_rtx_function (FILE *outfile, function *fn, bool compact);
@end smallexample
when "compact" is true. So you can capture RTL in the correct format
from the debugger using:
@smallexample
(gdb) print_rtx_function (stderr, cfun, true);
@end smallexample
and copy and paste the output into the body of the C function.
Example DejaGnu tests of RTL can be seen in the source tree under
@file{gcc/testsuite/gcc.dg/rtl}.
The @code{__RTL} parser is not integrated with the C tokenizer or
preprocessor, and works simply by reading the relevant lines within
the braces. In particular, the RTL body must be on separate lines from
the enclosing braces, and the preprocessor is not usable within it.