Handle machine mode specification with `const_double_zero' and handle
the rtx with callable code produced from named insns. Complementing
commit 20ab43b5cad6 ("RTL: Add `const_double_zero' syntactic rtx") and
removing a commit c60d0736dff7 ("PDP11: Use `const_double_zero' to
express double zero constant") build regression observed with the
`pdp11-aout' target:
genemit: Internal error: abort in gen_exp, at genemit.c:202
make[2]: *** [Makefile:2427: s-emit] Error 1
where a:
(const_double 0 [0] 0 [0] 0 [0] 0 [0])
rtx coming from:
(parallel [
(set (reg:CC 16)
(compare:CC (abs:DF (match_operand:DF 1 ("general_operand")
("0,0")))
(const_double 0 [0] 0 [0] 0 [0] 0 [0])))
(set (match_operand:DF 0 ("nonimmediate_operand") ("=fR,Q"))
(abs:DF (match_dup 1)))
])
and ultimately `(const_double_zero)' referred in a named RTL insn cannot
be interpreted. Handle the rtx then by supplying the constant 0 double
operand requested, resulting in the following update to insn-emit.c code
produced for the `pdp11-aout' target, relative to before the triggering
commit:
@@ -1514,7 +1514,7 @@ gen_absdf2_cc (rtx operand0 ATTRIBUTE_UN
gen_rtx_COMPARE (CCmode,
gen_rtx_ABS (DFmode,
operand1),
- const0_rtx)),
+ CONST_DOUBLE_ATOF ("0", VOIDmode))),
gen_rtx_SET (operand0,
gen_rtx_ABS (DFmode,
copy_rtx (operand1)))));
@@ -1555,7 +1555,7 @@ gen_negdf2_cc (rtx operand0 ATTRIBUTE_UN
gen_rtx_COMPARE (CCmode,
gen_rtx_NEG (DFmode,
operand1),
- const0_rtx)),
+ CONST_DOUBLE_ATOF ("0", VOIDmode))),
gen_rtx_SET (operand0,
gen_rtx_NEG (DFmode,
copy_rtx (operand1)))));
@@ -1790,7 +1790,7 @@ gen_muldf3_cc (rtx operand0 ATTRIBUTE_UN
gen_rtx_MULT (DFmode,
operand1,
operand2),
- const0_rtx)),
+ CONST_DOUBLE_ATOF ("0", VOIDmode))),
gen_rtx_SET (operand0,
gen_rtx_MULT (DFmode,
copy_rtx (operand1),
@@ -1942,7 +1942,7 @@ gen_divdf3_cc (rtx operand0 ATTRIBUTE_UN
gen_rtx_DIV (DFmode,
operand1,
operand2),
- const0_rtx)),
+ CONST_DOUBLE_ATOF ("0", VOIDmode))),
gen_rtx_SET (operand0,
gen_rtx_DIV (DFmode,
copy_rtx (operand1),
This does not (yet) remove VOIDmode CONST_DOUBLE use, as it is up to
individual machine descriptions to choose.
gcc/
* genemit.c (gen_exp) <CONST_DOUBLE>: Handle `const_double_zero'
rtx.
* read-rtl.c (rtx_reader::read_rtx_code): Handle machine mode
with `const_double_zero'.
* doc/rtl.texi (Constant Expression Types): Document it.
---
gcc/doc/rtl.texi | 4 ++--
gcc/genemit.c | 8 ++++++++
gcc/read-rtl.c | 9 +++++++++
3 files changed, 19 insertions(+), 2 deletions(-)
gcc-const-double-zero-mode.diff
Index: gcc/gcc/doc/rtl.texi
===================================================================
--- gcc.orig/gcc/doc/rtl.texi
+++ gcc/gcc/doc/rtl.texi
@@ -1719,13 +1719,13 @@ of code @code{const_double} and therefor
provided:
@smallexample
-(const_double_zero)
+(const_double_zero:@var{m})
@end smallexample
standing for:
@smallexample
-(const_double 0 0 @dots{})
+(const_double:@var{m} 0 0 @dots{})
@end smallexample
for matching the floating-point value zero, possibly the only useful one.
Index: gcc/gcc/genemit.c
===================================================================
--- gcc.orig/gcc/genemit.c
+++ gcc/gcc/genemit.c
@@ -195,6 +195,14 @@ gen_exp (rtx x, enum rtx_code subroutine
return;
case CONST_DOUBLE:
+ /* Handle `const_double_zero' rtx. */
+ if (CONST_DOUBLE_REAL_VALUE (x)->cl == rvc_zero)
+ {
+ printf ("CONST_DOUBLE_ATOF (\"0\", %smode)",
+ GET_MODE_NAME (GET_MODE (x)));
+ return;
+ }
+ /* Fall through. */
case CONST_FIXED:
case CONST_WIDE_INT:
/* These shouldn't be written in MD files. Instead, the appropriate
Index: gcc/gcc/read-rtl.c
===================================================================
--- gcc.orig/gcc/read-rtl.c
+++ gcc/gcc/read-rtl.c
@@ -1658,6 +1658,15 @@ rtx_reader::read_rtx_code (const char *c
return_rtx = rtx_alloc (code);
memset (return_rtx, 0, RTX_CODE_SIZE (code));
PUT_CODE (return_rtx, code);
+ c = read_skip_spaces ();
+ if (c == ':')
+ {
+ file_location loc = read_name (&name);
+ record_potential_iterator_use (&modes, loc, return_rtx, 0,
+ name.string);
+ }
+ else
+ unread_char (c);
return return_rtx;
}
