[Patch PR target/67366 2/2] [gimple-fold.c] Support movmisalign optabs in gimple-fold.c

[Richard Biener]

On Thu, Oct 8, 2015 at 4:10 PM, Ramana Radhakrishnan
<ramana.radhakrishnan@arm.com> wrote:
> This patch by Richard allows for movmisalign optabs to be supported
> in gimple-fold.c. This caused a bit of pain in the testsuite with strlenopt-8.c
> in conjunction with the ARM support for movmisalign_optabs as the test
> was coded up to do different things depending on whether the target
> supported misaligned access or not. However now with unaligned access
> being allowed for different levels of the architecture in the arm backend,
> the concept of the helper function non_strict_align mapping identically
> to the definition of STRICT_ALIGNMENT disappears.
>
> Adjusted thusly for ARM. The testsuite/lib changes were tested with an
> arm-none-eabi multilib that included architecture variants that did not
> support unaligned access and architecture variants that did.
>
> The testing matrix for this patch was:
>
> 1. x86_64 bootstrap and regression test - no regressions.
> 2. armhf bootstrap and regression test - no regressions.
> 3. arm-none-eabi cross build and regression test for
>
> {-marm/-march=armv7-a/-mfpu=vfpv3-d16/-mfloat-abi=softfp}
> {-mthumb/-march=armv8-a/-mfpu=crypto-neon-fp-armv8/-mfloat-abi=hard}
> {-marm/-mcpu=arm7tdmi/-mfloat-abi=soft}
> {-mthumb/-mcpu=arm7tdmi/-mfloat-abi=soft}
>
> with no regressions.
>
> Ok to apply ?

Ok.

Thanks,
Richard.

> Ramana
>
> 2015-10-08  Richard Biener  <rguenth@suse.de>
>
>         * gimple-fold.c (optabs-query.h): Include
>         (gimple_fold_builtin_memory_op): Allow unaligned stores
>         when movmisalign_optabs are available.
>
> 2015-10-08  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
>
>         PR target/67366
>         * lib/target-supports.exp (check_effective_target_non_strict_align):
>         Adjust for arm*-*-*.
>         * gcc.target/arm/pr67366.c: New test.
> ---
>  gcc/gimple-fold.c                      | 11 +++++++++--
>  gcc/testsuite/gcc.target/arm/pr67366.c | 14 ++++++++++++++
>  gcc/testsuite/lib/target-supports.exp  |  9 +++++++++
>  3 files changed, 32 insertions(+), 2 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.target/arm/pr67366.c
>
> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
> index a6caaa4..59d496b 100644
> --- a/gcc/gimple-fold.c
> +++ b/gcc/gimple-fold.c
> @@ -63,6 +63,8 @@ along with GCC; see the file COPYING3.  If not see
>  #include "tree-eh.h"
>  #include "gimple-match.h"
>  #include "gomp-constants.h"
> +#include "optabs-query.h"
> +
>
>  /* Return true when DECL can be referenced from current unit.
>     FROM_DECL (if non-null) specify constructor of variable DECL was taken from.
> @@ -709,7 +711,9 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
>                   /* If the destination pointer is not aligned we must be able
>                      to emit an unaligned store.  */
>                   && (dest_align >= GET_MODE_ALIGNMENT (TYPE_MODE (type))
> -                     || !SLOW_UNALIGNED_ACCESS (TYPE_MODE (type), dest_align)))
> +                     || !SLOW_UNALIGNED_ACCESS (TYPE_MODE (type), dest_align)
> +                     || (optab_handler (movmisalign_optab, TYPE_MODE (type))
> +                         != CODE_FOR_nothing)))
>                 {
>                   tree srctype = type;
>                   tree desttype = type;
> @@ -721,7 +725,10 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
>                     srcmem = tem;
>                   else if (src_align < GET_MODE_ALIGNMENT (TYPE_MODE (type))
>                            && SLOW_UNALIGNED_ACCESS (TYPE_MODE (type),
> -                                                    src_align))
> +                                                    src_align)
> +                          && (optab_handler (movmisalign_optab,
> +                                             TYPE_MODE (type))
> +                              == CODE_FOR_nothing))
>                     srcmem = NULL_TREE;
>                   if (srcmem)
>                     {
> diff --git a/gcc/testsuite/gcc.target/arm/pr67366.c b/gcc/testsuite/gcc.target/arm/pr67366.c
> new file mode 100644
> index 0000000..1e8b672
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/arm/pr67366.c
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target arm_unaligned } */
> +/* { dg-options "-O2" } */
> +
> +typedef unsigned int u32;
> +u32
> +read32 (const void* ptr)
> +{
> +  u32 v;
> +  __builtin_memcpy (&v, ptr, sizeof(v));
> +  return v;
> +}
> +
> +/* { dg-final { scan-assembler "@ unaligned" } } */
> diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> index 9057a27..4d5b0a3d 100644
> --- a/gcc/testsuite/lib/target-supports.exp
> +++ b/gcc/testsuite/lib/target-supports.exp
> @@ -6262,6 +6262,15 @@ proc check_vect_support_and_set_flags { } {
>  # Return 1 if the target does *not* require strict alignment.
>
>  proc check_effective_target_non_strict_align {} {
> +
> +    # On ARM, the default is to use STRICT_ALIGNMENT, but there
> +    # are interfaces defined for misaligned access and thus
> +    # depending on the architecture levels unaligned access is
> +    # available.
> +    if [istarget "arm*-*-*"] {
> +       return [check_effective_target_arm_unaligned]
> +    }
> +
>      return [check_no_compiler_messages non_strict_align assembly {
>         char *y;
>         typedef char __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))) c;