Hello,
Test gcc.c-torture/execute/ieee/pr72824-2.c fails for arm targets
because the code generated to move a vector of signed and unsigned zeros
treats it as a vector of unsigned zeros.
That is, an assignment x = { 0.f, -0.f, 0.f, -0.f } is treated as the
assignment x = { 0.f, 0.f, 0.f, 0.f }.
This is due to config/arm/arm.c/neon_valid_immediate using real_equal to
compare the vector elements. This patch replaces the check, using
const_vec_duplicate_p instead. It doesn't add a new test because
pr72824-2.c is enough to check the behaviour.
Tested for arm-none-linux-gnueabihf with native bootstrap and make check
and for arm-none-eabi with cross-compiled check-gcc.
2016-08-19 Matthew Wahab <matthew.wa...@arm.com>
PR target/77281
* config/arm/arm.c (neon_valid_immediate): Delete declaration.
Use const_vec_duplicate to check for duplicated elements.
Ok for trunk?
Matthew
>From 90c1c86b7a3d8bc6ac07363aea5fba8f29ef3e96 Mon Sep 17 00:00:00 2001
From: Matthew Wahab <matthew.wa...@arm.com>
Date: Wed, 17 Aug 2016 14:43:48 +0100
Subject: [PATCH] [ARM] Fix a wrong test for vectors of the same constants.
---
gcc/config/arm/arm.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index a6afdcc..c1d010c 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -12471,7 +12471,6 @@ neon_valid_immediate (rtx op, machine_mode mode, int inverse,
if (GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
{
rtx el0 = CONST_VECTOR_ELT (op, 0);
- const REAL_VALUE_TYPE *r0;
if (!vfp3_const_double_rtx (el0) && el0 != CONST0_RTX (GET_MODE (el0)))
return -1;
@@ -12480,14 +12479,10 @@ neon_valid_immediate (rtx op, machine_mode mode, int inverse,
if (GET_MODE_INNER (mode) == HFmode)
return -1;
- r0 = CONST_DOUBLE_REAL_VALUE (el0);
-
- for (i = 1; i < n_elts; i++)
- {
- rtx elt = CONST_VECTOR_ELT (op, i);
- if (!real_equal (r0, CONST_DOUBLE_REAL_VALUE (elt)))
- return -1;
- }
+ /* All elements in the vector must be the same. Note that 0.0 and -0.0
+ are distinct in this context. */
+ if (!const_vec_duplicate_p (op))
+ return -1;
if (modconst)
*modconst = CONST_VECTOR_ELT (op, 0);
--
2.1.4
