On Sun, Jul 10, 2011 at 9:36 AM, Paolo Bonzini <bonz...@gnu.org> wrote:
> On Sat, Jul 9, 2011 at 23:31, H.J. Lu <hjl.to...@gmail.com> wrote:
>> On Sat, Jul 9, 2011 at 2:18 PM, Paolo Bonzini <bonz...@gnu.org> wrote:
>>> On 07/05/2011 04:27 PM, H.J. Lu wrote:
>>>>>
>>>>> diff --git a/gcc/explow.c b/gcc/explow.c
>>>>> index 7387dad..b343bf8 100644
>>>>> --- a/gcc/explow.c
>>>>> +++ b/gcc/explow.c
>>>>> @@ -383,18 +383,13 @@ convert_memory_address_addr_space (enum
>>>>> machine_mode to_mode ATTRIBUTE_UNUSED,
>>>>>
>>>>> case PLUS:
>>>>> case MULT:
>>>>> - /* For addition we can safely permute the conversion and addition
>>>>> - operation if one operand is a constant and converting the
>>>>> constant
>>>>> - does not change it or if one operand is a constant and we are
>>>>> - using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED< 0).
>>>>> - We can always safely permute them if we are making the address
>>>>> - narrower. */
>>>>> + /* For addition we safely permute the conversion and addition
>>>>> + operation if one operand is a constant since we can't generate
>>>>> + new instructions. We can always safely permute them if we are
>>>>> + making the address narrower. */
>>>>> if (GET_MODE_SIZE (to_mode)< GET_MODE_SIZE (from_mode)
>>>>> || (GET_CODE (x) == PLUS
>>>>> -&& CONST_INT_P (XEXP (x, 1))
>>>>> -&& (XEXP (x, 1) == convert_memory_address_addr_space
>>>>> - (to_mode, XEXP (x, 1), as)
>>>>> - || POINTERS_EXTEND_UNSIGNED< 0)))
>>>>> +&& CONST_INT_P (XEXP (x, 1))))
>>>>> return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
>>>>> convert_memory_address_addr_space
>>>>> (to_mode, XEXP (x, 0), as),
>>>
>>> This does not seem safe to me.
>>
>> The current code is broken for x32. See:
>>
>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47727
>>
>> We can't generate any new instructions. Do you have any suggestions.
>
> By "safe" I mean that the new condition might be too wide and generate
> wrong code. Richard is definitely right in comment 6, generating new
> code in simplify-rtx is a no-no (see its usage of
> gen_lowpart_no_emit).
Here is a different approach. I added convert_memory_address_addr_space_1
and convert_modes_1 so that simplify-rtx won't generate new insns. OK
for trunk if there are no regressions on Linux/x86?
Thanks.
--
H.J.
---
2011-07-10 H.J. Lu <hongjiu...@intel.com>
* explow.c (convert_memory_address_addr_space_1): New.
(convert_memory_address_addr_space): Use it.
* expr.c (convert_modes_1): New.
(convert_modes): Use it.
* expr.h (convert_modes_1): New.
* rtl.h (convert_memory_address_addr_space_1): New.
(convert_memory_address_1): Likewise.
* simplify-rtx.c (simplify_unary_operation_1): Call
convert_memory_address_1 instead of convert_memory_address.
2011-07-10 H.J. Lu <hongjiu...@intel.com>
* explow.c (convert_memory_address_addr_space_1): New.
(convert_memory_address_addr_space): Use it.
* expr.c (convert_modes_1): New.
(convert_modes): Use it.
* expr.h (convert_modes_1): New.
* rtl.h (convert_memory_address_addr_space_1): New.
(convert_memory_address_1): Likewise.
* simplify-rtx.c (simplify_unary_operation_1): Call
convert_memory_address_1 instead of convert_memory_address.
diff --git a/gcc/explow.c b/gcc/explow.c
index 3c692f4..ee52e92 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -320,8 +320,9 @@ break_out_memory_refs (rtx x)
arithmetic insns can be used. */
rtx
-convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED,
- rtx x, addr_space_t as ATTRIBUTE_UNUSED)
+convert_memory_address_addr_space_1 (enum machine_mode to_mode
ATTRIBUTE_UNUSED,
+ rtx x, addr_space_t as ATTRIBUTE_UNUSED,
+ bool no_emit ATTRIBUTE_UNUSED)
{
#ifndef POINTERS_EXTEND_UNSIGNED
gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
@@ -406,10 +407,17 @@ convert_memory_address_addr_space (enum machine_mode
to_mode ATTRIBUTE_UNUSED,
break;
}
- return convert_modes (to_mode, from_mode,
- x, POINTERS_EXTEND_UNSIGNED);
+ return convert_modes_1 (to_mode, from_mode, x,
+ POINTERS_EXTEND_UNSIGNED, no_emit);
#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
}
+
+rtx
+convert_memory_address_addr_space (enum machine_mode to_mode,
+ rtx x, addr_space_t as)
+{
+ return convert_memory_address_addr_space_1 (to_mode, x, as, false);
+}
/* Return something equivalent to X but valid as a memory address for something
of mode MODE in the named address space AS. When X is not itself valid,
diff --git a/gcc/expr.c b/gcc/expr.c
index fb4379f..de7f150 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -693,13 +693,16 @@ convert_to_mode (enum machine_mode mode, rtx x, int
unsignedp)
Both modes may be floating, or both integer.
UNSIGNEDP is nonzero if X is an unsigned value.
+ If NO_EMIT is true, don't emit any instructions.
+
This can be done by referring to a part of X in place
or by copying to a new temporary with conversion.
You can give VOIDmode for OLDMODE, if you are sure X has a nonvoid mode. */
rtx
-convert_modes (enum machine_mode mode, enum machine_mode oldmode, rtx x, int
unsignedp)
+convert_modes_1 (enum machine_mode mode, enum machine_mode oldmode,
+ rtx x, int unsignedp, bool no_emit)
{
rtx temp;
@@ -709,7 +712,12 @@ convert_modes (enum machine_mode mode, enum machine_mode
oldmode, rtx x, int uns
if (GET_CODE (x) == SUBREG && SUBREG_PROMOTED_VAR_P (x)
&& GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))) >= GET_MODE_SIZE (mode)
&& SUBREG_PROMOTED_UNSIGNED_P (x) == unsignedp)
- x = gen_lowpart (mode, x);
+ {
+ if (no_emit)
+ x = rtl_hooks.gen_lowpart_no_emit (mode, x);
+ else
+ x = gen_lowpart (mode, x);
+ }
if (GET_MODE (x) != VOIDmode)
oldmode = GET_MODE (x);
@@ -773,7 +781,10 @@ convert_modes (enum machine_mode mode, enum machine_mode
oldmode, rtx x, int uns
return gen_int_mode (val, mode);
}
- return gen_lowpart (mode, x);
+ if (no_emit)
+ return rtl_hooks.gen_lowpart_no_emit (mode, x);
+ else
+ return gen_lowpart (mode, x);
}
/* Converting from integer constant into mode is always equivalent to an
@@ -784,10 +795,18 @@ convert_modes (enum machine_mode mode, enum machine_mode
oldmode, rtx x, int uns
return simplify_gen_subreg (mode, x, oldmode, 0);
}
+ gcc_assert (!no_emit);
temp = gen_reg_rtx (mode);
convert_move (temp, x, unsignedp);
return temp;
}
+
+rtx
+convert_modes (enum machine_mode mode, enum machine_mode oldmode,
+ rtx x, int unsignedp)
+{
+ return convert_modes_1 (mode, oldmode, x, unsignedp, false);
+}
/* Return the largest alignment we can use for doing a move (or store)
of MAX_PIECES. ALIGN is the largest alignment we could use. */
diff --git a/gcc/expr.h b/gcc/expr.h
index cb4050d..2ac9788 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -267,6 +267,8 @@ extern rtx convert_to_mode (enum machine_mode, rtx, int);
/* Convert an rtx to MODE from OLDMODE and return the result. */
extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
+extern rtx convert_modes_1 (enum machine_mode, enum machine_mode, rtx,
+ int, bool);
/* Emit code to move a block Y to a block X. */
diff --git a/gcc/rtl.h b/gcc/rtl.h
index e3ceecd..b01eef8 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1638,8 +1638,13 @@ extern int byte_lowpart_offset (enum machine_mode, enum
machine_mode);
extern rtx make_safe_from (rtx, rtx);
extern rtx convert_memory_address_addr_space (enum machine_mode, rtx,
addr_space_t);
+extern rtx convert_memory_address_addr_space_1 (enum machine_mode, rtx,
+ addr_space_t, bool);
#define convert_memory_address(to_mode,x) \
convert_memory_address_addr_space ((to_mode), (x), ADDR_SPACE_GENERIC)
+#define convert_memory_address_1(to_mode,x,no_emit) \
+ convert_memory_address_addr_space_1 ((to_mode), (x), \
+ ADDR_SPACE_GENERIC, (no_emit))
extern const char *get_insn_name (int);
extern rtx get_last_insn_anywhere (void);
extern rtx get_first_nonnote_insn (void);
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 82b818b..189c201 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -1150,7 +1150,7 @@ simplify_unary_operation_1 (enum rtx_code code, enum
machine_mode mode, rtx op)
&& REG_P (SUBREG_REG (op))
&& REG_POINTER (SUBREG_REG (op))
&& GET_MODE (SUBREG_REG (op)) == Pmode)))
- return convert_memory_address (Pmode, op);
+ return convert_memory_address_1 (Pmode, op, true);
#endif
break;
@@ -1243,7 +1243,7 @@ simplify_unary_operation_1 (enum rtx_code code, enum
machine_mode mode, rtx op)
&& REG_P (SUBREG_REG (op))
&& REG_POINTER (SUBREG_REG (op))
&& GET_MODE (SUBREG_REG (op)) == Pmode)))
- return convert_memory_address (Pmode, op);
+ return convert_memory_address_1 (Pmode, op, true);
#endif
break;
