RE: [PATCH][GCC] arm: Fix the warning -mcpu=cortex-m55 conflicting with -march=armv8.1-m.main (pr97327).

[Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>]

> -----Original Message-----
> From: Srinath Parvathaneni <Srinath.Parvathaneni@arm.com>
> Sent: 16 October 2020 14:21
> To: gcc-patches@gcc.gnu.org
> Cc: Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>
> Subject: [PATCH][GCC] arm: Fix the warning -mcpu=cortex-m55 conflicting
> with -march=armv8.1-m.main (pr97327).
> 
> Hello,
> 
> This patch fixes (PR97327) the warning -mcpu=cortex-m55 conflicts with -
> march=armv8.1-m.main
> for -mfloat-abi=soft by adding the isa_bit_mve_float to clearing FP bit list.
> 
> The following combination are fixed with this patch:
> $ cat bug.c
> int main(){
> return 0;
> }
> 
> $ arm-none-eabi-gcc -mcpu=cortex-m55 -mfloat-abi=soft bug.c -c
> $ arm-none-eabi-gcc -mcpu=cortex-m55 -mfloat-abi=soft -march=armv8.1-
> m.main+mve bug.c -c
> 
> Before this patch for above combinations:
> cc1: warning: switch '-mcpu=cortex-m55' conflicts with '-march=armv8.1-
> m.main' switch
> 
> After this patch for above combinations no warning/errors.
> 
> Regression tested on arm-none-eabi and found no regressions.
> 
> Ok for master? Ok for GCC-10 branch?

Ok for master and for the branch next week if testing shows no problem.
Thanks,
Kyrill

> 
> Regards,
> Srinath.
> 
> gcc/ChangeLog:
> 
> 2020-10-16  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>
> 
> 	PR target/97327
> 	* config/arm/arm.c (fp_bitlist): Add isa_bit_mve_float to FP bits
> array.
> 
> gcc/testsuite/ChangeLog:
> 
> 	PR target/97327
> 	* gcc.target/arm/mve/intrinsics/pr97327.c: New test.
> 
> 
> ###############     Attachment also inlined for ease of reply
> ###############
> 
> 
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index
> 0b8c5fa074d32e9ced107d1917323479c19d4c4e..dfadaca6fdfe16cfd5b6531
> ae8564d01063bbe77 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -3429,8 +3429,9 @@ arm_option_override (void)
>  {
>    static const enum isa_feature fpu_bitlist_internal[]
>      = { ISA_ALL_FPU_INTERNAL, isa_nobit };
> +  /* isa_bit_mve_float is also part of FP bit list for arch v8.1-m.main.  */
>    static const enum isa_feature fp_bitlist[]
> -    = { ISA_ALL_FP, isa_nobit };
> +    = { ISA_ALL_FP, isa_bit_mve_float, isa_nobit };
>    static const enum isa_feature quirk_bitlist[] = { ISA_ALL_QUIRKS, isa_nobit};
>    cl_target_option opts;
> 
> diff --git a/gcc/testsuite/gcc.target/arm/mve/intrinsics/pr97327.c
> b/gcc/testsuite/gcc.target/arm/mve/intrinsics/pr97327.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..8f6d36063811607623048
> c0a95920b29e43f4c39
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/arm/mve/intrinsics/pr97327.c
> @@ -0,0 +1,8 @@
> +/* { dg-require-effective-target arm_v8_1m_mve_fp_ok } */
> +/* { dg-skip-if "Incompatible float ABI" { *-*-* } { "-mfloat-abi=hard" } { "" } }
> */
> +/* { dg-additional-options "-mcpu=cortex-m55 -mfloat-abi=soft -
> mfpu=auto -Werror" } */
> +
> +int main ()
> +{
> +  return 0;
> +}