[PATCH] Append assembler flags on ARM targets

[David Holmes]

Hi Jakub,

I have filed:

https://bugs.openjdk.java.net/browse/JDK-8214466

for this issue and I have reviewed (along with Erik) and will sponsor.

Cheers,
David

On 26/11/2018 1:49 am, Jakub Vaněk wrote:
> Hi,
> 
> This patch is a redo of the ARM926EJ-S patch. It adds a mechanism of
> passing ARM CPU-specific flags to the assembler. This is achieved
> through sharing variables between  ABI setup and ASFLAGS setup. Then
> this patch adds pre-existing -march flags in CFLAGS to ASFLAGS as well.
> 
> An alternative way of doing this would be to set this directly in
> flags-other.m4, but this would lead to setting ARM CPU-specific flags
> on multiple places.
> 
> It is not possible to simply copy CFLAGS to ASFLAGS, because not all
> flags that the C compiler accepts are accepted by the assembler (e.g.
> -marm doesn't work).
> 
> The reason for this change is that on ARMv5, the non-E variants aren't
> supported anymore. This patch doesn't address this issue yet, but it
> adds the necessary infrastructure. I believe we need to set -march to
> ARMv5TE both in CFLAGS and in ASFLAGS, because the problem is in file
> linux_arm_32.s.
> 
> This patch in combination with a switch from ARMv5T to ARMv5TE was built successfully for the arm-sflt target:
> https://ci.adoptopenjdk.net/view/ev3dev/job/openjdk12_build_ev3_linux/21/
> 
> I have been successful in building arm-vfp-hflt configuration locally.
> 
> Thanks,
> 
> Jakub Vanek
> 
> # HG changeset patch
> # User Jakub Vaněk <linuxtardis at gmail.com>
> # Date 1543065692 -3600
> #      Sat Nov 24 14:21:32 2018 +0100
> # Node ID c5ff4e346842d9025e8abdde0cf8c7d33dfd8d82
> # Parent  30a02b4e6c06e874ec8735dedb7e894844b1d627
> Append assembler flags on ARM targets
> 
> diff --git a/make/autoconf/flags-other.m4 b/make/autoconf/flags-
> other.m4
> --- a/make/autoconf/flags-other.m4
> +++ b/make/autoconf/flags-other.m4
> @@ -119,6 +119,12 @@
>     # Misuse EXTRA_CFLAGS to mimic old behavior
>     $2JVM_ASFLAGS="$JVM_BASIC_ASFLAGS ${$2EXTRA_CFLAGS}"
>   
> +  if test "x$1" = "xTARGET" && \
> +      test "x$TOOLCHAIN_TYPE" = xgcc && \
> +      test "x$OPENJDK_TARGET_CPU" = xarm; then
> +    $2JVM_ASFLAGS="${$2JVM_ASFLAGS} $ARM_ARCH_TYPE_ASFLAGS
> $ARM_FLOAT_TYPE_ASFLAGS"
> +  fi
> +
>     AC_SUBST($2JVM_ASFLAGS)
>   ])
>   
> diff --git a/make/autoconf/flags.m4 b/make/autoconf/flags.m4
> --- a/make/autoconf/flags.m4
> +++ b/make/autoconf/flags.m4
> @@ -49,38 +49,52 @@
>       if test "x$OPENJDK_TARGET_ABI_PROFILE" = xarm-vfp-sflt; then
>         ARM_FLOAT_TYPE=vfp-sflt
>         ARM_ARCH_TYPE_FLAGS='-march=armv7-a -mthumb'
> +      ARM_ARCH_TYPE_ASFLAGS='-march=armv7-a -mthumb'
>       elif test "x$OPENJDK_TARGET_ABI_PROFILE" = xarm-vfp-hflt; then
>         ARM_FLOAT_TYPE=vfp-hflt
>         ARM_ARCH_TYPE_FLAGS='-march=armv7-a -mthumb'
> +      ARM_ARCH_TYPE_ASFLAGS='-march=armv7-a -mthumb'
>       elif test "x$OPENJDK_TARGET_ABI_PROFILE" = xarm-sflt; then
>         ARM_FLOAT_TYPE=sflt
>         ARM_ARCH_TYPE_FLAGS='-march=armv5t -marm'
> +      ARM_ARCH_TYPE_ASFLAGS='-march=armv5t'
>       elif test "x$OPENJDK_TARGET_ABI_PROFILE" = xarmv5-vfp-sflt; then
>         ARM_FLOAT_TYPE=vfp-sflt
>         ARM_ARCH_TYPE_FLAGS='-march=armv5t -marm'
> +      ARM_ARCH_TYPE_ASFLAGS='-march=armv5t'
>       elif test "x$OPENJDK_TARGET_ABI_PROFILE" = xarmv6-vfp-hflt; then
>         ARM_FLOAT_TYPE=vfp-hflt
>         ARM_ARCH_TYPE_FLAGS='-march=armv6 -marm'
> +      ARM_ARCH_TYPE_ASFLAGS='-march=armv6'
>       elif test "x$OPENJDK_TARGET_ABI_PROFILE" = xaarch64; then
>         # No special flags, just need to trigger setting
> JDK_ARCH_ABI_PROP_NAME
>         ARM_FLOAT_TYPE=
>         ARM_ARCH_TYPE_FLAGS=
> +      ARM_ARCH_TYPE_ASFLAGS=
>       else
>         AC_MSG_ERROR([Invalid ABI profile:
> "$OPENJDK_TARGET_ABI_PROFILE"])
>       fi
>   
>       if test "x$ARM_FLOAT_TYPE" = xvfp-sflt; then
>         ARM_FLOAT_TYPE_FLAGS='-mfloat-abi=softfp -mfpu=vfp
> -DFLOAT_ARCH=-vfp-sflt'
> +      ARM_FLOAT_TYPE_ASFLAGS="-mfloat-abi=softfp -mfpu=vfp"
>       elif test "x$ARM_FLOAT_TYPE" = xvfp-hflt; then
>         ARM_FLOAT_TYPE_FLAGS='-mfloat-abi=hard -mfpu=vfp -DFLOAT_ARCH=-
> vfp-hflt'
> +      ARM_FLOAT_TYPE_ASFLAGS="-mfloat-abi=hard -mfpu=vfp"
>       elif test "x$ARM_FLOAT_TYPE" = xsflt; then
>         ARM_FLOAT_TYPE_FLAGS='-msoft-float -mfpu=vfp'
> +      ARM_FLOAT_TYPE_ASFLAGS="-mfloat-abi=soft -mfpu=vfp"
>       fi
> +
>       AC_MSG_CHECKING([for $ARM_FLOAT_TYPE floating point flags])
>       AC_MSG_RESULT([$ARM_FLOAT_TYPE_FLAGS])
> +    AC_MSG_CHECKING([for $ARM_FLOAT_TYPE floating point flags for
> assembler])
> +    AC_MSG_RESULT([$ARM_FLOAT_TYPE_ASFLAGS])
>   
>       AC_MSG_CHECKING([for arch type flags])
>       AC_MSG_RESULT([$ARM_ARCH_TYPE_FLAGS])
> +    AC_MSG_CHECKING([for arch type flags for assembler])
> +    AC_MSG_RESULT([$ARM_ARCH_TYPE_ASFLAGS])
>   
>       # Now set JDK_ARCH_ABI_PROP_NAME. This is equivalent to the last
> part of the
>       # autoconf target triplet.
> 
> 
> 
>