On Tue, Jan 20, 2015 at 5:06 AM, Thomas Preud'homme
<thomas.preudho...@arm.com> wrote:
> Currently on GCC 4.8 and 4.9, constant pool entries for QImode, HImode and
> SImode values are filled as 32-bit quantities. This works fine for little
> endian system but gives some incorrect results for big endian system when the
> value is accessed with a mode smaller than 32-bit in size. Suppose the case
> of the value 0x1234 that is accessed as an HImode value. It would be output
> as 0x0 0x0 0x12 0x34 in a constant pool entry and the 16-bit load that would
> be done would lead to the value 0x0 in register.
>
> This patch makes the consttable_1 and consttable_2 pattern available to ARM
> as well so that values are output according to their mode.
>
> This is a backport of commit r218118.
>
> *** gcc/ChangeLog ***
>
> 2015-01-14 Thomas Preud'homme <thomas.preudho...@arm.com>
>
> Backport from mainline
> 2014-11-27 Thomas Preud'homme <thomas.preudho...@arm.com>
>
> PR target/59593
> * config/arm/arm.c (dump_minipool): dispatch to consttable pattern
> based on mode size.
> * config/arm/arm.md (consttable_1): Make it TARGET_EITHER.
> (consttable_2): Make it TARGET_EITHER and move HFmode handling from
> consttable_4 to it.
> (consttable_4): Move HFmode handling to consttable_2 pattern.
>
>
> *** gcc/testsuite/ChangeLog ***
>
> 2015-01-14 Thomas Preud'homme <thomas.preudho...@arm.com>
>
> Backport from mainline
> 2014-11-27 Thomas Preud'homme <thomas.preudho...@arm.com>
>
> PR target/59593
> * gcc.target/arm/constant-pool.c: New test.
>
>
> diff --git a/gcc/ChangeLog b/gcc/ChangeLog
> index 85372e5..eeaece8 100644
> --- a/gcc/ChangeLog
> +++ b/gcc/ChangeLog
> @@ -1,3 +1,16 @@
> +2015-01-14 Thomas Preud'homme <thomas.preudho...@arm.com>
> +
> + Backport from mainline
> + 2014-11-27 Thomas Preud'homme <thomas.preudho...@arm.com>
> +
> + PR target/59593
> + * config/arm/arm.c (dump_minipool): dispatch to consttable pattern
> + based on mode size.
> + * config/arm/arm.md (consttable_1): Make it TARGET_EITHER.
> + (consttable_2): Make it TARGET_EITHER and move HFmode handling from
> + consttable_4 to it.
> + (consttable_4): Move HFmode handling to consttable_2 pattern.
> +
> 2015-01-14 Marek Polacek <pola...@redhat.com>
>
> Backport from mainline
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index 5e2571c..67ef80b 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -16274,7 +16274,7 @@ dump_minipool (rtx scan)
> fputc ('\n', dump_file);
> }
>
> - switch (mp->fix_size)
> + switch (GET_MODE_SIZE (mp->mode))
> {
> #ifdef HAVE_consttable_1
> case 1:
> diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
> index 8119387..93b25e9 100644
> --- a/gcc/config/arm/arm.md
> +++ b/gcc/config/arm/arm.md
> @@ -12224,7 +12224,7 @@
>
> (define_insn "consttable_1"
> [(unspec_volatile [(match_operand 0 "" "")] VUNSPEC_POOL_1)]
> - "TARGET_THUMB1"
> + "TARGET_EITHER"
> "*
> making_const_table = TRUE;
> assemble_integer (operands[0], 1, BITS_PER_WORD, 1);
> @@ -12237,14 +12237,23 @@
>
> (define_insn "consttable_2"
> [(unspec_volatile [(match_operand 0 "" "")] VUNSPEC_POOL_2)]
> - "TARGET_THUMB1"
> + "TARGET_EITHER"
> "*
> - making_const_table = TRUE;
> - gcc_assert (GET_MODE_CLASS (GET_MODE (operands[0])) != MODE_FLOAT);
> - assemble_integer (operands[0], 2, BITS_PER_WORD, 1);
> - assemble_zeros (2);
> - return \"\";
> - "
> + {
> + rtx x = operands[0];
> + making_const_table = TRUE;
> + switch (GET_MODE_CLASS (GET_MODE (x)))
> + {
> + case MODE_FLOAT:
> + arm_emit_fp16_const (x);
> + break;
> + default:
> + assemble_integer (operands[0], 2, BITS_PER_WORD, 1);
> + assemble_zeros (2);
> + break;
> + }
> + return \"\";
> + }"
> [(set_attr "length" "4")
> (set_attr "type" "no_insn")]
> )
> @@ -12259,15 +12268,12 @@
> switch (GET_MODE_CLASS (GET_MODE (x)))
> {
> case MODE_FLOAT:
> - if (GET_MODE (x) == HFmode)
> - arm_emit_fp16_const (x);
> - else
> - {
> - REAL_VALUE_TYPE r;
> - REAL_VALUE_FROM_CONST_DOUBLE (r, x);
> - assemble_real (r, GET_MODE (x), BITS_PER_WORD);
> - }
> - break;
> + {
> + REAL_VALUE_TYPE r;
> + REAL_VALUE_FROM_CONST_DOUBLE (r, x);
> + assemble_real (r, GET_MODE (x), BITS_PER_WORD);
> + break;
> + }
> default:
> /* XXX: Sometimes gcc does something really dumb and ends up with
> a HIGH in a constant pool entry, usually because it's trying to
> diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
> index 222716d..49d1a73 100644
> --- a/gcc/testsuite/ChangeLog
> +++ b/gcc/testsuite/ChangeLog
> @@ -1,3 +1,11 @@
> +2015-01-14 Thomas Preud'homme <thomas.preudho...@arm.com>
> +
> + Backport from mainline
> + 2014-11-27 Thomas Preud'homme <thomas.preudho...@arm.com>
> +
> + PR target/59593
> + * gcc.target/arm/constant-pool.c: New test.
> +
> 2015-01-14 Marek Polacek <pola...@redhat.com>
>
> Backport from mainline
> diff --git a/gcc/testsuite/gcc.target/arm/constant-pool.c
> b/gcc/testsuite/gcc.target/arm/constant-pool.c
> new file mode 100644
> index 0000000..8427dfb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/arm/constant-pool.c
> @@ -0,0 +1,27 @@
> +/* { dg-do run } */
> +/* { dg-options "-O1" } */
> +
> +unsigned short v = 0x5678;
> +int i;
> +int j = 0;
> +int *ptr = &j;
> +
> +int
> +func (void)
> +{
> + for (i = 0; i < 1; ++i)
> + {
> + *ptr = -1;
> + v = 0x1234;
> + }
> + return v;
> +}
> +
> +int
> +main (void)
> +{
> + func ();
> + if (v != 0x1234)
> + __builtin_abort ();
> + return 0;
> +}
>
>
> Is this ok for 4.8 and 4.9 branches?
Ok if no regressions and no RM objects to this in 24 hours. I think
it's baked sufficiently on trunk to backport now.
Ramana
>
> Best regards,
>
> Thomas
>
>
>
