This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH 1/2] Allow REG_EQUAL for ZERO_EXTRACT
- From: Kugan <kugan dot vivekanandarajah at linaro dot org>
- To: Maxim Kuvyrkov <maxim dot kuvyrkov at linaro dot org>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 30 Jun 2015 13:54:23 +1000
- Subject: Re: [PATCH 1/2] Allow REG_EQUAL for ZERO_EXTRACT
- Authentication-results: sourceware.org; auth=none
- References: <558FD9D5 dot 9070703 at linaro dot org> <558FDA78 dot 9030606 at linaro dot org> <F76C1ECD-DD43-415F-A896-BE7EA6A5330F at linaro dot org>
On 29/06/15 21:56, Maxim Kuvyrkov wrote:
>> On Jun 28, 2015, at 2:28 PM, Kugan <kugan.vivekanandarajah@linaro.org> wrote:
>>
>> This patch allows setting REG_EQUAL for ZERO_EXTRACT and handle that in
>> cse (where the src for the ZERO_EXTRACT needs to be calculated)
>>
>> Thanks,
>> Kugan
>
>> From 75e746e559ffd21b25542b3db627e3b318118569 Mon Sep 17 00:00:00 2001
>> From: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org>
>> Date: Fri, 26 Jun 2015 17:12:07 +1000
>> Subject: [PATCH 1/2] Allow adding REG_EQUAL for ZERO_EXTRACT
>>
>> ---
>> gcc/ChangeLog | 6 ++++++
>> gcc/cse.c | 41 ++++++++++++++++++++++++++++++++++++++++-
>> gcc/emit-rtl.c | 3 ++-
>> 3 files changed, 48 insertions(+), 2 deletions(-)
>>
>> diff --git a/gcc/ChangeLog b/gcc/ChangeLog
>> index 080aa39..d4a73d6 100644
>> --- a/gcc/ChangeLog
>> +++ b/gcc/ChangeLog
>> @@ -1,3 +1,9 @@
>> +2015-06-26 Kugan Vivekanandarajah <kuganv@linaro.org>
>> +
>> + * cse.c (cse_insn): Calculate src_eqv for ZERO_EXTRACT.
>> + * emit-rtl.c (set_for_reg_notes): Allow ZERO_EXTRACT to set
>> + REG_EQUAL note.
>> +
>> 2015-06-25 H.J. Lu <hongjiu.lu@intel.com>
>>
>> * gentarget-def.c (def_target_insn): Cast return of strtol to
>> diff --git a/gcc/cse.c b/gcc/cse.c
>> index 100c9c8..8add651 100644
>> --- a/gcc/cse.c
>> +++ b/gcc/cse.c
>> @@ -4531,8 +4531,47 @@ cse_insn (rtx_insn *insn)
>> if (n_sets == 1 && REG_NOTES (insn) != 0
>> && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0
>> && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl))
>> + || GET_CODE (SET_DEST (sets[0].rtl)) == ZERO_EXTRACT
>> || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART))
>> - src_eqv = copy_rtx (XEXP (tem, 0));
>> + {
>> + src_eqv = copy_rtx (XEXP (tem, 0));
>> +
>> + /* If DEST is of the form ZERO_EXTACT, as in:
>> + (set (zero_extract:SI (reg:SI 119)
>> + (const_int 16 [0x10])
>> + (const_int 16 [0x10]))
>> + (const_int 51154 [0xc7d2]))
>> + REG_EQUAL note will specify the value of register (reg:SI 119) at this
>> + point. Note that this is different from SRC_EQV. We can however
>> + calculate SRC_EQV with the position and width of ZERO_EXTRACT. */
>> + if (GET_CODE (SET_DEST (sets[0].rtl)) == ZERO_EXTRACT)
>
> Consider changing
>
> if (something
> && (!rtx_equal_p)
> || ZERO_EXTRACT
> || STRICT_LOW_PART)
>
> to
>
> if (something
> && !rtx_equal_p)
> {
> if (ZERO_EXTRACT)
> {
> }
> else if (STRICT_LOW_PART)
> {
> }
> }
>
> Otherwise looks good to me, but you still need another approval.
Thanks Maxim for the review. How about the attached patch?
Thanks,
Kugan
>
>
>> + {
>> + if (CONST_INT_P (src_eqv)
>> + && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 1))
>> + && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 2)))
>> + {
>> + rtx dest_reg = XEXP (SET_DEST (sets[0].rtl), 0);
>> + rtx width = XEXP (SET_DEST (sets[0].rtl), 1);
>> + rtx pos = XEXP (SET_DEST (sets[0].rtl), 2);
>> + HOST_WIDE_INT val = INTVAL (src_eqv);
>> + HOST_WIDE_INT mask;
>> + unsigned int shift;
>> + if (BITS_BIG_ENDIAN)
>> + shift = GET_MODE_PRECISION (GET_MODE (dest_reg))
>> + - INTVAL (pos) - INTVAL (width);
>> + else
>> + shift = INTVAL (pos);
>> + if (INTVAL (width) == HOST_BITS_PER_WIDE_INT)
>> + mask = ~(HOST_WIDE_INT) 0;
>> + else
>> + mask = ((HOST_WIDE_INT) 1 << INTVAL (width)) - 1;
>> + val = (val >> shift) & mask;
>> + src_eqv = GEN_INT (val);
>> + }
>> + else
>> + src_eqv = 0;
>> + }
>> + }
>>
>> /* Set sets[i].src_elt to the class each source belongs to.
>> Detect assignments from or to volatile things
>> diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
>> index e7f7eab..cb891b1 100644
>> --- a/gcc/emit-rtl.c
>> +++ b/gcc/emit-rtl.c
>> @@ -5228,7 +5228,8 @@ set_for_reg_notes (rtx insn)
>> reg = SET_DEST (pat);
>>
>> /* Notes apply to the contents of a STRICT_LOW_PART. */
>> - if (GET_CODE (reg) == STRICT_LOW_PART)
>> + if (GET_CODE (reg) == STRICT_LOW_PART
>> + || GET_CODE (reg) == ZERO_EXTRACT)
>> reg = XEXP (reg, 0);
>>
>> /* Check that we have a register. */
>> --
>> 1.9.1
>>
>>
>
>
> --
> Maxim Kuvyrkov
> www.linaro.org
>
>
>
>
>From 3754bcd11fb732e03a39d6625a9eb14934b36643 Mon Sep 17 00:00:00 2001
From: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org>
Date: Fri, 26 Jun 2015 17:12:07 +1000
Subject: [PATCH 1/2] Allow adding REG_EQUAL for ZERO_EXTRACT
---
gcc/ChangeLog | 6 ++++++
gcc/cse.c | 49 ++++++++++++++++++++++++++++++++++++++++++-------
gcc/emit-rtl.c | 3 ++-
3 files changed, 50 insertions(+), 8 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 080aa39..d4a73d6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-06-26 Kugan Vivekanandarajah <kuganv@linaro.org>
+
+ * cse.c (cse_insn): Calculate src_eqv for ZERO_EXTRACT.
+ * emit-rtl.c (set_for_reg_notes): Allow ZERO_EXTRACT to set
+ REG_EQUAL note.
+
2015-06-25 H.J. Lu <hongjiu.lu@intel.com>
* gentarget-def.c (def_target_insn): Cast return of strtol to
diff --git a/gcc/cse.c b/gcc/cse.c
index 100c9c8..ea9e989 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -4525,14 +4525,49 @@ cse_insn (rtx_insn *insn)
canonicalize_insn (insn, &sets, n_sets);
/* If this insn has a REG_EQUAL note, store the equivalent value in SRC_EQV,
- if different, or if the DEST is a STRICT_LOW_PART. The latter condition
- is necessary because SRC_EQV is handled specially for this case, and if
- it isn't set, then there will be no equivalence for the destination. */
+ if different, or if the DEST is a STRICT_LOW_PART/ZERO_EXTRACT. The
+ latter condition is necessary because SRC_EQV is handled specially for
+ this case, and if it isn't set, then there will be no equivalence
+ for the destination. */
if (n_sets == 1 && REG_NOTES (insn) != 0
- && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0
- && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl))
- || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART))
- src_eqv = copy_rtx (XEXP (tem, 0));
+ && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0)
+ {
+ if ((! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl)))
+ || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART)
+ src_eqv = copy_rtx (XEXP (tem, 0));
+
+ /* If DEST is of the form ZERO_EXTACT, as in:
+ (set (zero_extract:SI (reg:SI 119)
+ (const_int 16 [0x10])
+ (const_int 16 [0x10]))
+ (const_int 51154 [0xc7d2]))
+ REG_EQUAL note will specify the value of register (reg:SI 119) at this
+ point. Note that this is different from SRC_EQV. We can however
+ calculate SRC_EQV with the position and width of ZERO_EXTRACT. */
+ else if (GET_CODE (SET_DEST (sets[0].rtl)) == ZERO_EXTRACT
+ &&CONST_INT_P (src_eqv)
+ && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 1))
+ && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 2)))
+ {
+ rtx dest_reg = XEXP (SET_DEST (sets[0].rtl), 0);
+ rtx width = XEXP (SET_DEST (sets[0].rtl), 1);
+ rtx pos = XEXP (SET_DEST (sets[0].rtl), 2);
+ HOST_WIDE_INT val = INTVAL (src_eqv);
+ HOST_WIDE_INT mask;
+ unsigned int shift;
+ if (BITS_BIG_ENDIAN)
+ shift = GET_MODE_PRECISION (GET_MODE (dest_reg))
+ - INTVAL (pos) - INTVAL (width);
+ else
+ shift = INTVAL (pos);
+ if (INTVAL (width) == HOST_BITS_PER_WIDE_INT)
+ mask = ~(HOST_WIDE_INT) 0;
+ else
+ mask = ((HOST_WIDE_INT) 1 << INTVAL (width)) - 1;
+ val = (val >> shift) & mask;
+ src_eqv = GEN_INT (val);
+ }
+ }
/* Set sets[i].src_elt to the class each source belongs to.
Detect assignments from or to volatile things
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index e7f7eab..cb891b1 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -5228,7 +5228,8 @@ set_for_reg_notes (rtx insn)
reg = SET_DEST (pat);
/* Notes apply to the contents of a STRICT_LOW_PART. */
- if (GET_CODE (reg) == STRICT_LOW_PART)
+ if (GET_CODE (reg) == STRICT_LOW_PART
+ || GET_CODE (reg) == ZERO_EXTRACT)
reg = XEXP (reg, 0);
/* Check that we have a register. */
--
1.9.1