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Re: [ARM] PR 47553: vld1q_lane_u8 & co. don't accept lanes >= 8
- From: Ramana Radhakrishnan <ramana dot radhakrishnan at linaro dot org>
- To: gcc-patches at gcc dot gnu dot org, richard dot sandiford at linaro dot org
- Cc: Richard Earnshaw <rearnsha at arm dot com>, paul at codesourcery dot com, nickc at redhat dot com
- Date: Tue, 15 Mar 2011 13:14:54 +0000
- Subject: Re: [ARM] PR 47553: vld1q_lane_u8 & co. don't accept lanes >= 8
- References: <g48vy18aqh.fsf@linaro.org>
On 31/01/11 13:27, Richard Sandiford wrote:
The v{ld,st}1q_lane_{u,s,p}8 intrinsic functions are supposed to take a range
between 0 and 15. The function is then converted to a vld1 or vst1 of one half
of the quad value. The problem is that the lane predicate doesn't account for
this, and only accepts the 0..7 range that are supported by the individual
vld1 and vst1.
The current code only does the "real" size-dependent range check at
output time. That isn't ideal, but there's a separate bug (40884)
about it.
Tested on arm-linux-gnueabi (-marm and -mthumb). I don't think this
is a regression, so: OK to install once 4.7 is open?
OK for trunk.
I am tempted to consider this one for the other release branches since
this is correcting a test in the interface for an intrinsic which has
been wrong for a long time but would like the opinion of the other
maintainers about this.
cheers
Ramana
Richard
gcc/
* config/arm/predicates.md (neon_lane_number): Accept 0..15.
gcc/testsuite/
* gcc.target/arm/neon-vld-1.c: New test.
Index: gcc/config/arm/predicates.md
===================================================================
--- gcc/config/arm/predicates.md 2011-01-31 13:09:19.000000000 +0000
+++ gcc/config/arm/predicates.md 2011-01-31 13:12:41.000000000 +0000
@@ -610,7 +610,7 @@ (define_predicate "neon_inv_logic_op2"
;; TODO: We could check lane numbers more precisely based on the mode.
(define_predicate "neon_lane_number"
(and (match_code "const_int")
- (match_test "INTVAL (op)>= 0&& INTVAL (op)<= 7")))
+ (match_test "INTVAL (op)>= 0&& INTVAL (op)<= 15")))
;; Predicates for named expanders that overlap multiple ISAs.
(define_predicate "cmpdi_operand"
Index: gcc/testsuite/gcc.target/arm/neon-vld-1.c
===================================================================
--- /dev/null 2011-01-26 10:43:14.268819722 +0000
+++ gcc/testsuite/gcc.target/arm/neon-vld-1.c 2011-01-31 13:16:10.000000000 +0000
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_neon_ok } */
+/* { dg-options "-O1" } */
+/* { dg-add-options arm_neon } */
+
+#include<arm_neon.h>
+
+uint8x16_t
+foo (uint8_t *a, uint8x16_t b)
+{
+ vst1q_lane_u8 (a, b, 14);
+ return vld1q_lane_u8 (a + 0x100, b, 15);
+}