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Prevent creation of paradoxical FLOAT_MODE subregs 

From-SVN: r55064
This commit is contained in:
Bernd Schmidt 2002-06-28 15:43:54 +00:00 committed by Bernd Schmidt
parent 20c2d1fea3
commit 53501a19fa
3 changed files with 39 additions and 12 deletions
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6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2001-06-08 Bernd Schmidt <bernds@redhat.com>
* emit-rtl.c (gen_lowpart_common): Don't create paradoxical FLOAT_MODE
subregs.
* recog.c (general_operand, register_operand): Disallow them.
2002-06-28 Neil Booth <neil@daikokuya.co.uk>
PR preprocessor/7138

5
gcc/emit-rtl.c
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@ -964,6 +964,11 @@ gen_lowpart_common (mode, x)
> ((xsize + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)))
return 0;
/* Don't allow generating paradoxical FLOAT_MODE subregs. */
if (GET_MODE_CLASS (mode) == MODE_FLOAT
&& GET_MODE (x) != VOIDmode && msize > xsize)
return 0;
offset = subreg_lowpart_offset (mode, GET_MODE (x));
if ((GET_CODE (x) == ZERO_EXTEND || GET_CODE (x) == SIGN_EXTEND)

40
gcc/recog.c
View File

@ -958,11 +958,13 @@ general_operand (op, mode)
if (code == SUBREG)
{
rtx sub = SUBREG_REG (op);
#ifdef INSN_SCHEDULING
/* On machines that have insn scheduling, we want all memory
reference to be explicit, so outlaw paradoxical SUBREGs. */
if (GET_CODE (SUBREG_REG (op)) == MEM
&& GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op))))
if (GET_CODE (sub) == MEM
&& GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (sub)))
return 0;
#endif
/* Avoid memories with nonzero SUBREG_BYTE, as offsetting the memory
@ -972,10 +974,16 @@ general_operand (op, mode)
??? This is a kludge. */
if (!reload_completed && SUBREG_BYTE (op) != 0
&& GET_CODE (SUBREG_REG (op)) == MEM)
&& GET_CODE (sub) == MEM)
return 0;
op = SUBREG_REG (op);
/* FLOAT_MODE subregs can't be paradoxical. Combine will occasionally
create such rtl, and we must reject it. */
if (GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT
&& GET_MODE_SIZE (GET_MODE (op)) > GET_MODE_SIZE (GET_MODE (sub)))
return 0;
op = sub;
code = GET_CODE (op);
}
@ -1048,28 +1056,36 @@ register_operand (op, mode)
if (GET_CODE (op) == SUBREG)
{
rtx sub = SUBREG_REG (op);
/* Before reload, we can allow (SUBREG (MEM...)) as a register operand
because it is guaranteed to be reloaded into one.
Just make sure the MEM is valid in itself.
(Ideally, (SUBREG (MEM)...) should not exist after reload,
but currently it does result from (SUBREG (REG)...) where the
reg went on the stack.) */
if (! reload_completed && GET_CODE (SUBREG_REG (op)) == MEM)
if (! reload_completed && GET_CODE (sub) == MEM)
return general_operand (op, mode);
#ifdef CLASS_CANNOT_CHANGE_MODE
if (GET_CODE (SUBREG_REG (op)) == REG
&& REGNO (SUBREG_REG (op)) < FIRST_PSEUDO_REGISTER
if (GET_CODE (sub) == REG
&& REGNO (sub) < FIRST_PSEUDO_REGISTER
&& (TEST_HARD_REG_BIT
(reg_class_contents[(int) CLASS_CANNOT_CHANGE_MODE],
REGNO (SUBREG_REG (op))))
&& CLASS_CANNOT_CHANGE_MODE_P (mode, GET_MODE (SUBREG_REG (op)))
&& GET_MODE_CLASS (GET_MODE (SUBREG_REG (op))) != MODE_COMPLEX_INT
&& GET_MODE_CLASS (GET_MODE (SUBREG_REG (op))) != MODE_COMPLEX_FLOAT)
REGNO (sub)))
&& CLASS_CANNOT_CHANGE_MODE_P (mode, GET_MODE (sub))
&& GET_MODE_CLASS (GET_MODE (sub)) != MODE_COMPLEX_INT
&& GET_MODE_CLASS (GET_MODE (sub)) != MODE_COMPLEX_FLOAT)
return 0;
#endif
op = SUBREG_REG (op);
/* FLOAT_MODE subregs can't be paradoxical. Combine will occasionally
create such rtl, and we must reject it. */
if (GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT
&& GET_MODE_SIZE (GET_MODE (op)) > GET_MODE_SIZE (GET_MODE (sub)))
return 0;
op = sub;
}
/* If we have an ADDRESSOF, consider it valid since it will be