Hi Jakub,
On 26/11/2018 1:53 am, Jakub Vaněk wrote:
Hi,
This patch raises the minimum architectural level for ARM CPUs to
ARMv5TE. It is done through changing the -march flag in the current
CPU-specific CFLAGS and ASFLAGS.
This patch depends on "Append assembler flags on ARM targets" patch for
ASFLAGS handling.
Reason for this change: assembler code in linux_arm_32.s uses PLD
instructions. ARM ISA manual mentions this: "This instruction is
available in E variants of ARM architecture v5 and above." (thanks to
David Holmes for noticing this).
FYI I did a bit of digging and we tried to make this change back in 2010
and ran into problems:
"It appears that gcc assumes that if you choose the armv5te architecture
option, it can use the "E" instruction extensions which provide 64 bit
load and stores to 4 byte aligned addresses. I tried two different
compiler versions 4.1.2 and 4.2.3 and they both had the same problem.
The <hardware> does support ldrd/strd but they do not support 4 byte
aligned operations. The addresses must be 8 byte aligned."
How things stand today I can not say.
Cheers,
David
This patch was successfully built here:
https://ci.adoptopenjdk.net/view/ev3dev/job/openjdk12_build_ev3_linux/21/
Thanks,
Jakub Vanek
# HG changeset patch
# User Jakub Vaněk <[email protected]>
# Date 1543065765 -3600
# Sat Nov 24 14:22:45 2018 +0100
# Node ID 1876e24fad75579f76e3106121e61f7951b03fc8
# Parent c5ff4e346842d9025e8abdde0cf8c7d33dfd8d82
Upgrade arm-sflt minimum architecture to ARMv5TE
diff --git a/make/autoconf/flags.m4 b/make/autoconf/flags.m4
--- a/make/autoconf/flags.m4
+++ b/make/autoconf/flags.m4
@@ -56,12 +56,12 @@
ARM_ARCH_TYPE_ASFLAGS='-march=armv7-a -mthumb'
elif test "x$OPENJDK_TARGET_ABI_PROFILE" = xarm-sflt; then
ARM_FLOAT_TYPE=sflt
- ARM_ARCH_TYPE_FLAGS='-march=armv5t -marm'
- ARM_ARCH_TYPE_ASFLAGS='-march=armv5t'
+ ARM_ARCH_TYPE_FLAGS='-march=armv5te -marm'
+ ARM_ARCH_TYPE_ASFLAGS='-march=armv5te'
elif test "x$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'
+ ARM_ARCH_TYPE_FLAGS='-march=armv5te -marm'
+ ARM_ARCH_TYPE_ASFLAGS='-march=armv5te'
elif test "x$OPENJDK_TARGET_ABI_PROFILE" = xarmv6-vfp-hflt; then
ARM_FLOAT_TYPE=vfp-hflt
ARM_ARCH_TYPE_FLAGS='-march=armv6 -marm'
