testsuite: Avoid running incompatible Arm tests

Ok for trunk and releases/gcc-14?

--

Overriding the -mpfu and -mfloat-abi might be incompatible with selected
multilib. As a result, verify that the current multilib is compatible
with the effective target without changing the -mfpu or -mfloat-abi
options.

gcc/testsuite/ChangeLog:

	* lib/target-supports.exp
	(check_effective_target_arm_hard_vfp_ok): Check -mfpu value.
	(check_effective_target_arm_fp16_alternative_ok_nocache):
	Reuse check_effective_target_arm_fp16_ok.
	(check_effective_target_arm_fp16_none_ok_nocache): Likewise.
	(check_effective_target_arm_v8_neon_ok_nocache): Align checks
	with skeleton from check_effective_target_arm_fp16_ok_nocache.
	(check_effective_target_arm_neonv2_ok_nocache): Likewise.

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
Co-authored-by: Yvan ROUX <yvan.roux@foss.st.com>
---
 gcc/testsuite/lib/target-supports.exp | 119 ++++++++++++++++++--------
 1 file changed, 83 insertions(+), 36 deletions(-)

On 12/07/2024 09:02, Torbjörn SVENSSON wrote:
> Ok for trunk and releases/gcc-14?
> 
> --
> 
> Overriding the -mpfu and -mfloat-abi might be incompatible with selected
> multilib. As a result, verify that the current multilib is compatible
> with the effective target without changing the -mfpu or -mfloat-abi
> options.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* lib/target-supports.exp
> 	(check_effective_target_arm_hard_vfp_ok): Check -mfpu value.
> 	(check_effective_target_arm_fp16_alternative_ok_nocache):
> 	Reuse check_effective_target_arm_fp16_ok.
> 	(check_effective_target_arm_fp16_none_ok_nocache): Likewise.
> 	(check_effective_target_arm_v8_neon_ok_nocache): Align checks
> 	with skeleton from check_effective_target_arm_fp16_ok_nocache.
> 	(check_effective_target_arm_neonv2_ok_nocache): Likewise.> 

Hmm, this is a tricky one.  I really want to be moving away from any value being passed to -mfpu other than "auto" and this looks like it's moving in the wrong direction.

Which tests does this affect?

R.

> Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
> Co-authored-by: Yvan ROUX <yvan.roux@foss.st.com>
> ---
>  gcc/testsuite/lib/target-supports.exp | 119 ++++++++++++++++++--------
>  1 file changed, 83 insertions(+), 36 deletions(-)
> 
> diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> index f001c28072f..f90b80bb495 100644
> --- a/gcc/testsuite/lib/target-supports.exp
> +++ b/gcc/testsuite/lib/target-supports.exp
> @@ -4829,6 +4829,7 @@ proc check_effective_target_arm_v8_vfp_ok {} {
>  
>  proc check_effective_target_arm_hard_vfp_ok { } {
>      if { [check_effective_target_arm32]
> +	 && ! [check-flags [list "" { *-*-* } { "-mfpu=*" } { "-mfpu=vfp" }]]
>  	 && ! [check-flags [list "" { *-*-* } { "-mfloat-abi=*" } { "-mfloat-abi=hard" }]] } {
>  	return [check_no_compiler_messages arm_hard_vfp_ok executable {
>  	    int main() { return 0;}
> @@ -5405,11 +5406,12 @@ proc check_effective_target_arm_fp16_alternative_ok_nocache { } {
>  	# Not supported by the target system.
>  	return 0
>      }
> +    global et_arm_fp16_flags
>      global et_arm_fp16_alternative_flags
>      set et_arm_fp16_alternative_flags ""
> -    if { [check_effective_target_arm32] } {
> -	foreach flags {"" "-mfloat-abi=softfp" "-mfpu=neon-fp16"
> -		       "-mfpu=neon-fp16 -mfloat-abi=softfp"} {
> +
> +    if { [check_effective_target_arm32] && [check_effective_target_arm_fp16_ok] } {
> +	foreach flags [list "" $et_arm_fp16_flags] {
>  	    if { [check_no_compiler_messages_nocache \
>  		      arm_fp16_alternative_ok object {
>  		#if !defined (__ARM_FP16_FORMAT_ALTERNATIVE) || ! (__ARM_FP & 2)
> @@ -5434,9 +5436,9 @@ proc check_effective_target_arm_fp16_alternative_ok { } {
>  # format.  Some multilibs may be incompatible with the options needed.
>  
>  proc check_effective_target_arm_fp16_none_ok_nocache { } {
> -    if { [check_effective_target_arm32] } {
> -	foreach flags {"" "-mfloat-abi=softfp" "-mfpu=neon-fp16"
> -		       "-mfpu=neon-fp16 -mfloat-abi=softfp"} {
> +    global et_arm_fp16_flags
> +    if { [check_effective_target_arm32] && [check_effective_target_arm_fp16_ok] } {
> +	foreach flags [list "" $et_arm_fp16_flags] {
>  	    if { [check_no_compiler_messages_nocache \
>  		      arm_fp16_none_ok object {
>  		#if defined (__ARM_FP16_FORMAT_ALTERNATIVE)
> @@ -5467,23 +5469,46 @@ proc check_effective_target_arm_fp16_none_ok { } {
>  proc check_effective_target_arm_v8_neon_ok_nocache { } {
>      global et_arm_v8_neon_flags
>      set et_arm_v8_neon_flags ""
> -    if { [check_effective_target_arm32] } {
> -	foreach flags {"" "-mfloat-abi=softfp" "-mfpu=neon-fp-armv8" "-mfpu=neon-fp-armv8 -mfloat-abi=softfp"} {
> -	    if { [check_no_compiler_messages_nocache arm_v8_neon_ok object {
> -		#if __ARM_ARCH < 8
> -		#error not armv8 or later
> -		#endif
> -		#include "arm_neon.h"
> -		void
> -		foo ()
> -		{
> -		  __asm__ volatile ("vrintn.f32 q0, q0");
> -		}
> -	    } "$flags -march=armv8-a"] } {
> -		set et_arm_v8_neon_flags $flags
> -		return 1
> -	    }
> +    if { ! [check_effective_target_arm32] } {
> +	return 0;
> +    }
> +    if [check-flags \
> +	    [list "" { *-*-* } { "-mfpu=*" } \
> +		 { "-mfpu=*fp-armv8*" } ]] {
> +	# Multilib flags would override -mfpu.
> +	return 0
> +    }
> +    if [check-flags [list "" { *-*-* } { "-mfloat-abi=soft" } { "" } ]] {
> +	# Must generate floating-point instructions.
> +	return 0
> +    }
> +    if [check_effective_target_arm_hf_eabi] {
> +	# Use existing float-abi and force an fpu which supports fp16
> +	set et_arm_v8_neon_flags "-mfpu=neon-fp-armv8"
> +	return 1;
> +    }
> +    if [check-flags [list "" { *-*-* } { "-mfpu=*" } { "" } ]] {
> +	# The existing -mfpu value is OK; use it, but add softfp.
> +	set et_arm_v8_neon_flags "-mfloat-abi=softfp"
> +	return 1;
> +    }
> +
> +    # Add -mfpu for a VFP fp16 variant since there is no preprocessor
> +    # macro to check for this support.
> +    set flags "-mfpu=neon-fp-armv8 -mfloat-abi=softfp"
> +    if { [check_no_compiler_messages_nocache arm_v8_neon_ok object {
> +	#if __ARM_ARCH < 8
> +	#error not armv8 or later
> +	#endif
> +	#include "arm_neon.h"
> +	void
> +	foo ()
> +	{
> +	  __asm__ volatile ("vrintn.f32 q0, q0");
>  	}
> +    } "$flags -march=armv8-a"] } {
> +	set et_arm_v8_neon_flags $flags
> +	return 1
>      }
>  
>      return 0
> @@ -5503,21 +5528,43 @@ proc check_effective_target_arm_neonv2_ok_nocache { } {
>      global et_arm_neonv2_flags
>      global et_arm_neon_flags
>      set et_arm_neonv2_flags ""
> -    if { [check_effective_target_arm32]
> -	 && [check_effective_target_arm_neon_ok] } {
> -	foreach flags {"" "-mfloat-abi=softfp" "-mfpu=neon-vfpv4" "-mfpu=neon-vfpv4 -mfloat-abi=softfp"} {
> -	    if { [check_no_compiler_messages_nocache arm_neonv2_ok object {
> -		#include "arm_neon.h"
> -		float32x2_t
> -		foo (float32x2_t a, float32x2_t b, float32x2_t c)
> -		{
> -		  return vfma_f32 (a, b, c);
> -		}
> -	    } "$et_arm_neon_flags $flags"] } {
> -		set et_arm_neonv2_flags [concat $et_arm_neon_flags $flags]
> -		return 1
> -	    }
> +    if { ! [check_effective_target_arm32] || ! [check_effective_target_arm_neon_ok] } {
> +	return 0;
> +    }
> +    if [check-flags \
> +	    [list "" { *-*-* } { "-mfpu=*" } \
> +		 { "-mfpu=*fp16*" "-mfpu=*fpv[4-9]*" \
> +		       "-mfpu=*fpv[1-9][0-9]*" "-mfpu=*fp-armv8*" } ]] {
> +	# Multilib flags would override -mfpu.
> +	return 0
> +    }
> +    if [check-flags [list "" { *-*-* } { "-mfloat-abi=soft" } { "" } ]] {
> +	# Must generate floating-point instructions.
> +	return 0
> +    }
> +    if [check_effective_target_arm_hf_eabi] {
> +	# Use existing float-abi and force an fpu which supports neonv2
> +	set et_arm_neonv2_flags [concat $et_arm_neon_flags "-mfpu=vfpv4"]
> +	return 1;
> +    }
> +    if [check-flags [list "" { *-*-* } { "-mfpu=*" } { "" } ]] {
> +	# The existing -mfpu value is OK; use it, but add softfp.
> +	set et_arm_neonv2_flags [concat $et_arm_neon_flags "-mfloat-abi=softfp"]
> +	return 1;
> +    }
> +    # Add -mfpu for a neonv2 variant since there is no preprocessor
> +    # macro to check for this support.
> +    set flags "-mfpu=vfpv4 -mfloat-abi=softfp"
> +    if { [check_no_compiler_messages_nocache arm_neonv2_ok object {
> +	#include "arm_neon.h"
> +	float32x2_t
> +	foo (float32x2_t a, float32x2_t b, float32x2_t c)
> +	{
> +	  return vfma_f32 (a, b, c);
>  	}
> +    } "$et_arm_neon_flags $flags"] } {
> +	set et_arm_neonv2_flags [concat $et_arm_neon_flags $flags]
> +	return 1
>      }
>  
>      return 0