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arch/arm: add options for FPv5 FPU

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Contrary to its older brother, the FPv5 comes in two flavours; single-
and double-precision [0] [1]. the two variants are only available for
cortex-m7 cores, and the two variants are known to gcc as fpv5-sp-d16
and fpv5-d16, respectively, since gcc-5 [2].

[0] https://en.wikipedia.org/wiki/ARM_Cortex-M#Cortex-M7
[1] https://developer.arm.com/docs/ddi0489/latest/floating-point-unit
[2] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=a076f99fa702deac764f6e0441b9435ad999f521

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
This commit is contained in:
Yann E. MORIN 2018-02-25 21:18:16 +01:00 committed by Thomas Petazzoni
parent 09c6e28233
commit 81d8a25bc8
1 changed files with 37 additions and 0 deletions
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37
arch/Config.in.arm
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@ -49,6 +49,15 @@ config BR2_ARM_CPU_HAS_FPV4
bool
select BR2_ARM_CPU_HAS_FPU
# FPv5 is always optional
config BR2_ARM_CPU_MAYBE_HAS_FPV5
bool
select BR2_ARM_CPU_MAYBE_HAS_FPV4
config BR2_ARM_CPU_HAS_FPV5
bool
select BR2_ARM_CPU_HAS_FPV4
config BR2_ARM_CPU_HAS_FP_ARMV8
bool
select BR2_ARM_CPU_HAS_VFPV4
@ -469,6 +478,7 @@ config BR2_ARM_ENABLE_NEON
config BR2_ARM_ENABLE_VFP
bool "Enable VFP extension support"
depends on BR2_ARM_CPU_MAYBE_HAS_FPU
select BR2_ARM_CPU_HAS_FPV5 if BR2_ARM_CPU_MAYBE_HAS_FPV5
select BR2_ARM_CPU_HAS_FPV4 if BR2_ARM_CPU_MAYBE_HAS_FPV4
select BR2_ARM_CPU_HAS_VFPV4 if BR2_ARM_CPU_MAYBE_HAS_VFPV4
select BR2_ARM_CPU_HAS_VFPV3 if BR2_ARM_CPU_MAYBE_HAS_VFPV3
@ -536,6 +546,7 @@ endchoice
choice
prompt "Floating point strategy"
default BR2_ARM_FPU_FP_ARMV8 if BR2_ARM_CPU_HAS_FP_ARMV8
default BR2_ARM_FPU_FPV5D16 if BR2_ARM_CPU_HAS_FPV5
default BR2_ARM_FPU_FPV4D16 if BR2_ARM_CPU_HAS_FPV4
default BR2_ARM_FPU_VFPV4D16 if BR2_ARM_CPU_HAS_VFPV4
default BR2_ARM_FPU_VFPV3D16 if BR2_ARM_CPU_HAS_VFPV3
@ -655,6 +666,30 @@ config BR2_ARM_FPU_FPV4D16
floating point unit, as available in some ARMv7m processors
(Cortex-M4).
config BR2_ARM_FPU_FPV5D16
bool "FPv5-D16"
depends on BR2_ARM_CPU_HAS_FPV5
select BR2_ARCH_NEEDS_GCC_AT_LEAST_5
help
This option allows to use the FPv5-SP (single precision)
floating point unit, as available in some ARMv7m processors
(Cortex-M7).
Note that if you want binary code that works on the earlier
Cortex-M4, you should instead select FPv4-D16.
config BR2_ARM_FPU_FPV5DPD16
bool "FPv5-DP-D16"
depends on BR2_ARM_CPU_HAS_FPV5
select BR2_ARCH_NEEDS_GCC_AT_LEAST_5
help
This option allows to use the FPv5-DP (double precision)
floating point unit, as available in some ARMv7m processors
(Cortex-M7).
Note that if you want binary code that works on the earlier
Cortex-M4, you should instead select FPv4-D16.
config BR2_ARM_FPU_FP_ARMV8
bool "FP-ARMv8"
depends on BR2_ARM_CPU_HAS_FP_ARMV8
@ -788,6 +823,8 @@ config BR2_GCC_TARGET_FPU
default "neon" if BR2_ARM_FPU_NEON
default "neon-vfpv4" if BR2_ARM_FPU_NEON_VFPV4
default "fpv4-sp-d16" if BR2_ARM_FPU_FPV4D16
default "fpv5-sp-d16" if BR2_ARM_FPU_FPV5D16
default "fpv5-d16" if BR2_ARM_FPU_FPV5DPD16
default "fp-armv8" if BR2_ARM_FPU_FP_ARMV8
default "neon-fp-armv8" if BR2_ARM_FPU_NEON_FP_ARMV8
depends on BR2_arm || BR2_armeb