From: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
To: GCC Patches <gcc-patches@gcc.gnu.org>,
Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>
Cc: nd <nd@arm.com>, Richard Earnshaw <Richard.Earnshaw@arm.com>
Subject: Re: [PATCH][ARM] Fix ldrd offsets
Date: Thu, 20 Apr 2017 16:07:00 -0000 [thread overview]
Message-ID: <AM5PR0802MB2610482FBEF057A1298450DB831B0@AM5PR0802MB2610.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <AM5PR0802MB2610C0616A19887E6FA5928E83A30@AM5PR0802MB2610.eurprd08.prod.outlook.com>
ping
From: Wilco Dijkstra
Sent: 03 November 2016 12:20
To: GCC Patches
Cc: nd
Subject: [PATCH][ARM] Fix ldrd offsets
Fix ldrd offsets of Thumb-2 - for TARGET_LDRD the range is +-1020,
without -255..4091. This reduces the number of addressing instructions
when using DI mode operations (such as in PR77308).
Bootstrap & regress OK.
ChangeLog:
2015-11-03 Wilco Dijkstra <wdijkstr@arm.com>
gcc/
* config/arm/arm.c (arm_legitimate_index_p): Add comment.
(thumb2_legitimate_index_p): Use correct range for DI/DF mode.
--
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 3c4c7042d9c2101619722b5822b3d1ca37d637b9..5d12cf9c46c27d60a278d90584bde36ec86bb3fe 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -7486,6 +7486,8 @@ arm_legitimate_index_p (machine_mode mode, rtx index, RTX_CODE outer,
{
HOST_WIDE_INT val = INTVAL (index);
+ /* Assume we emit ldrd or 2x ldr if !TARGET_LDRD.
+ If vldr is selected it uses arm_coproc_mem_operand. */
if (TARGET_LDRD)
return val > -256 && val < 256;
else
@@ -7613,11 +7615,13 @@ thumb2_legitimate_index_p (machine_mode mode, rtx index, int strict_p)
if (code == CONST_INT)
{
HOST_WIDE_INT val = INTVAL (index);
- /* ??? Can we assume ldrd for thumb2? */
- /* Thumb-2 ldrd only has reg+const addressing modes. */
- /* ldrd supports offsets of +-1020.
- However the ldr fallback does not. */
- return val > -256 && val < 256 && (val & 3) == 0;
+ /* Thumb-2 ldrd only has reg+const addressing modes.
+ Assume we emit ldrd or 2x ldr if !TARGET_LDRD.
+ If vldr is selected it uses arm_coproc_mem_operand. */
+ if (TARGET_LDRD)
+ return IN_RANGE (val, -1020, 1020) && (val & 3) == 0;
+ else
+ return IN_RANGE (val, -255, 4095 - 4);
}
else
return 0;
next prev parent reply other threads:[~2017-04-20 16:03 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-03 12:21 Wilco Dijkstra
2016-11-08 14:08 ` Ramana Radhakrishnan
2016-11-11 10:59 ` Wilco Dijkstra
2016-12-06 15:13 ` Wilco Dijkstra
2016-12-14 16:41 ` Wilco Dijkstra
2017-01-17 12:12 ` Wilco Dijkstra
2017-02-02 14:45 ` Wilco Dijkstra
2017-02-23 16:57 ` Wilco Dijkstra
2017-04-20 16:07 ` Wilco Dijkstra [this message]
2017-06-13 13:59 ` Wilco Dijkstra
2017-06-27 15:39 ` Wilco Dijkstra
2017-09-04 17:00 ` Kyrill Tkachov
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