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md.texi: Describe the use of match_tests in attribute tests.

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gcc/
	* doc/md.texi: Describe the use of match_tests in attribute tests.
	* rtl.def (MATCH_TEST): Update commentary.
	* genattrtab.c (attr_copy_rtx, check_attr_test, clear_struct_flag)
	(write_test_expr, walk_attr_value): Handle MATCH_TEST.

From-SVN: r178388
This commit is contained in:
Richard Sandiford 2011-08-31 21:06:59 +00:00 • committed by Richard Sandiford
parent 091ace5877
commit 0c0d395770
4 changed files with 47 additions and 3 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2011-08-31 Richard Sandiford <rdsandiford@googlemail.com>
* doc/md.texi: Describe the use of match_tests in attribute tests.
* rtl.def (MATCH_TEST): Update commentary.
* genattrtab.c (attr_copy_rtx, check_attr_test, clear_struct_flag)
(write_test_expr, walk_attr_value): Handle MATCH_TEST.
2011-08-31 Richard Sandiford <rdsandiford@googlemail.com>
* genattrtab.c (attr_rtx_1): Hash SYMBOL_REFs.

24
gcc/doc/md.texi
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@ -7045,6 +7045,30 @@ string).
The @var{constraints} operand is ignored and should be the null string.
@cindex @code{match_test} and attributes
@item (match_test @var{c-expr})
The test is true if C expression @var{c-expr} is true. In non-constant
attributes, @var{c-expr} has access to the following variables:
@table @var
@item insn
The rtl instruction under test.
@item which_alternative
The @code{define_insn} alternative that @var{insn} matches.
@xref{Output Statement}.
@item operands
An array of @var{insn}'s rtl operands.
@end table
@var{c-expr} behaves like the condition in a C @code{if} statement,
so there is no need to explicitly convert the expression into a boolean
0 or 1 value. For example, the following two tests are equivalent:
@smallexample
(match_test "x & 2")
(match_test "(x & 2) != 0")
@end smallexample
@cindex @code{le} and attributes
@cindex @code{leu} and attributes
@cindex @code{lt} and attributes

14
gcc/genattrtab.c
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@ -658,6 +658,7 @@ attr_copy_rtx (rtx orig)
case CONST_DOUBLE:
case CONST_VECTOR:
case SYMBOL_REF:
case MATCH_TEST:
case CODE_LABEL:
case PC:
case CC0:
@ -841,6 +842,11 @@ check_attr_test (rtx exp, int is_const, int lineno)
XEXP (exp, 0) = check_attr_test (XEXP (exp, 0), is_const, lineno);
break;
case MATCH_TEST:
exp = attr_rtx (MATCH_TEST, XSTR (exp, 0));
ATTR_IND_SIMPLIFIED_P (exp) = 1;
break;
case MATCH_OPERAND:
if (is_const)
fatal ("RTL operator \"%s\" not valid in constant attribute test",
@ -2907,6 +2913,7 @@ clear_struct_flag (rtx x)
case CONST_INT:
case CONST_DOUBLE:
case CONST_VECTOR:
case MATCH_TEST:
case SYMBOL_REF:
case CODE_LABEL:
case PC:
@ -3571,6 +3578,12 @@ write_test_expr (rtx exp, unsigned int attrs_cached, int flags)
printf (HOST_WIDE_INT_PRINT_DEC, XWINT (exp, 0));
break;
case MATCH_TEST:
print_c_condition (XSTR (exp, 0));
if (flags & FLG_BITWISE)
printf (" != 0");
break;
/* A random C expression. */
case SYMBOL_REF:
print_c_condition (XSTR (exp, 0));
@ -3765,6 +3778,7 @@ walk_attr_value (rtx exp)
must_extract = 1;
return;
case MATCH_TEST:
case EQ_ATTR_ALT:
must_extract = must_constrain = 1;
break;

5
gcc/rtl.def
View file

@ -819,9 +819,8 @@ DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", RTX_MATCH)
the result of the one before it. */
DEF_RTL_EXPR(MATCH_CODE, "match_code", "ss", RTX_MATCH)
/* Appears only in define_predicate/define_special_predicate
expressions. The argument is a C expression to be injected at this
point in the predicate formula. */
/* Used to inject a C conditional expression into an .md file. It can
appear in a predicate definition or an attribute expression. */
DEF_RTL_EXPR(MATCH_TEST, "match_test", "s", RTX_MATCH)
/* Insn (and related) definitions. */