CSKY: Add -mfloat-abi= option.

gcc/ChangeLog:

	* config/csky/csky_opts.h (float_abi_type): New.
	* config/csky/csky.h (TARGET_SOFT_FLOAT): New.
	(TARGET_HARD_FLOAT): New.
	(TARGET_HARD_FLOAT_ABI): New.
	(OPTION_DEFAULT_SPECS): Use mfloat-abi.
	* config/csky/csky.opt (mfloat-abi): New.
	* doc/invoke.texi (C-SKY Options): Document -mfloat-abi=.

---
 gcc/config/csky/csky.h      |  9 ++++++++-
 gcc/config/csky/csky.opt    | 29 +++++++++++++++++++++++++----
 gcc/config/csky/csky_opts.h |  7 +++++++
 gcc/doc/invoke.texi         | 18 ++++++++++++++++++
 4 files changed, 58 insertions(+), 5 deletions(-)

Committed to trunk, Thanks.


Xianmiao

On 7/31/20 3:18 PM, Jojo R wrote:
> gcc/ChangeLog:
>
> 	* config/csky/csky_opts.h (float_abi_type): New.
> 	* config/csky/csky.h (TARGET_SOFT_FLOAT): New.
> 	(TARGET_HARD_FLOAT): New.
> 	(TARGET_HARD_FLOAT_ABI): New.
> 	(OPTION_DEFAULT_SPECS): Use mfloat-abi.
> 	* config/csky/csky.opt (mfloat-abi): New.
> 	* doc/invoke.texi (C-SKY Options): Document -mfloat-abi=.
>
> ---
>   gcc/config/csky/csky.h      |  9 ++++++++-
>   gcc/config/csky/csky.opt    | 29 +++++++++++++++++++++++++----
>   gcc/config/csky/csky_opts.h |  7 +++++++
>   gcc/doc/invoke.texi         | 18 ++++++++++++++++++
>   4 files changed, 58 insertions(+), 5 deletions(-)
>
> diff --git a/gcc/config/csky/csky.h b/gcc/config/csky/csky.h
> index 2d5a66ca187..8f4090b4b38 100644
> --- a/gcc/config/csky/csky.h
> +++ b/gcc/config/csky/csky.h
> @@ -126,6 +126,13 @@
>   #define TARGET_TLS \
>     (CSKY_TARGET_ARCH (CK807) || CSKY_TARGET_ARCH (CK810))
>   
> +/* Run-time Target Specification.  */
> +#define TARGET_SOFT_FLOAT       (csky_float_abi == CSKY_FLOAT_ABI_SOFT)
> +/* Use hardware floating point instructions. */
> +#define TARGET_HARD_FLOAT       (csky_float_abi != CSKY_FLOAT_ABI_SOFT)
> +/* Use hardware floating point calling convention.  */
> +#define TARGET_HARD_FLOAT_ABI   (csky_float_abi == CSKY_FLOAT_ABI_HARD)
> +
>   /* Number of loads/stores handled by ldm/stm.  */
>   #define CSKY_MIN_MULTIPLE_STLD	3
>   #define CSKY_MAX_MULTIPLE_STLD	12
> @@ -818,7 +825,7 @@ while (0)
>     {"arch", "%{!march=*:%{!mcpu=*:-march=%(VALUE)}}" }, \
>     {"cpu", "%{!march=*:%{!mcpu=*:-mcpu=%(VALUE)}}" }, \
>     {"endian", "%{!mbig-endian:%{!mlittle-endian:-m%(VALUE)-endian}}" }, \
> -  {"float", "%{!msoft-float:%{!mhard-float:-m%(VALUE)-float}}" },
> +  {"float", "%{!mfloat-abi=*:-mfloat-abi=%(VALUE)}" },
>   
>   
>   /******************************************************************
> diff --git a/gcc/config/csky/csky.opt b/gcc/config/csky/csky.opt
> index 5846e50344f..60b51e5798f 100644
> --- a/gcc/config/csky/csky.opt
> +++ b/gcc/config/csky/csky.opt
> @@ -57,12 +57,33 @@ Target RejectNegative Report Alias(mlittle-endian) Undocumented
>   ;; assembly.
>   
>   mhard-float
> -Target Report RejectNegative Mask(HARD_FLOAT)
> -Enable hardware floating-point instructions.
> +Target RejectNegative Alias(mfloat-abi=, hard) Undocumented
>   
>   msoft-float
> -Target Report RejectNegative InverseMask(HARD_FLOAT)
> -Use library calls to perform floating-point operations (default).
> +Target RejectNegative Alias(mfloat-abi=, soft) Undocumented
> +
> +mfloat-abi=v2
> +Target RejectNegative Alias(mfloat-abi=, hard) Undocumented
> +
> +mfloat-abi=v1
> +Target RejectNegative Alias(mfloat-abi=, softfp) Undocumented
> +
> +mfloat-abi=
> +Target RejectNegative Joined Enum(float_abi_type) Var(csky_float_abi) Init(CSKY_FLOAT_ABI_SOFT)
> +Specify if floating point hardware should be used.
> +
> +Enum
> +Name(float_abi_type) Type(enum float_abi_type)
> +Known floating-point ABIs (for use with the -mfloat-abi= option):
> +
> +EnumValue
> +Enum(float_abi_type) String(soft) Value(CSKY_FLOAT_ABI_SOFT)
> +
> +EnumValue
> +Enum(float_abi_type) String(softfp) Value(CSKY_FLOAT_ABI_SOFTFP)
> +
> +EnumValue
> +Enum(float_abi_type) String(hard) Value(CSKY_FLOAT_ABI_HARD)
>   
>   mfpu=
>   Target RejectNegative Joined Enum(csky_fpu) Var(csky_fpu_index) Init(TARGET_FPU_auto) Save
> diff --git a/gcc/config/csky/csky_opts.h b/gcc/config/csky/csky_opts.h
> index a6dbf5ab6dd..7ee56be3e81 100644
> --- a/gcc/config/csky/csky_opts.h
> +++ b/gcc/config/csky/csky_opts.h
> @@ -59,5 +59,12 @@ enum csky_fpu_type
>   };
>   #define CSKY_TARGET_FPU_GET(name) TARGET_FPU_ ## name
>   
> +enum float_abi_type
> +{
> +  CSKY_FLOAT_ABI_SOFT,
> +  CSKY_FLOAT_ABI_SOFTFP,
> +  CSKY_FLOAT_ABI_HARD
> +};
> +
>   
>   #endif /* CSKY_OPTS_H */
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index eaaf6d06b65..a132e09c674 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -820,6 +820,7 @@ Objective-C and Objective-C++ Dialects}.
>   @gccoptlist{-march=@var{arch}  -mcpu=@var{cpu} @gol
>   -mbig-endian  -EB  -mlittle-endian  -EL @gol
>   -mhard-float  -msoft-float  -mfpu=@var{fpu}  -mdouble-float  -mfdivdu @gol
> +-mfloat-abi=@var{name} @gol
>   -melrw  -mistack  -mmp  -mcp  -mcache  -msecurity  -mtrust @gol
>   -mdsp  -medsp  -mvdsp @gol
>   -mdiv  -msmart  -mhigh-registers  -manchor @gol
> @@ -20644,6 +20645,23 @@ Specify the C-SKY target processor.  Valid values for @var{cpu} are:
>   
>   Select big- or little-endian code.  The default is little-endian.
>   
> +@item -mfloat-abi=@var{name}
> +@opindex mfloat-abi
> +Specifies which floating-point ABI to use.  Permissible values
> +are: @samp{soft}, @samp{softfp} and @samp{hard}.
> +
> +Specifying @samp{soft} causes GCC to generate output containing
> +library calls for floating-point operations.
> +@samp{softfp} allows the generation of code using hardware floating-point
> +instructions, but still uses the soft-float calling conventions.
> +@samp{hard} allows generation of floating-point instructions
> +and uses FPU-specific calling conventions.
> +
> +The default depends on the specific target configuration.  Note that
> +the hard-float and soft-float ABIs are not link-compatible; you must
> +compile your entire program with the same ABI, and link with a
> +compatible set of libraries.
> +
>   @item -mhard-float
>   @opindex mhard-float
>   @itemx -msoft-float

My glibc bot is showing the build of libgcc for csky-linux-gnuabiv2 
(configured --with-float=hard --disable-multilib) has recently broken, 
likely from this change.

https://sourceware.org/pipermail/libc-testresults/2020q3/006566.html

The errors are of the form:

/tmp/cc7H0Zu7.s: Assembler messages:
/tmp/cc7H0Zu7.s:24: Error: The instruction is not recognized.
/tmp/cc7H0Zu7.s:28: Error: The instruction is not recognized.
/tmp/cc7H0Zu7.s:42: Error: The instruction is not recognized.
/tmp/cc7H0Zu7.s:52: Error: The instruction is not recognized.
/tmp/cc7H0Zu7.s:63: Error: The instruction is not recognized.
/tmp/cc7H0Zu7.s:67: Error: The instruction is not recognized.
/tmp/cc7H0Zu7.s:73: Error: The instruction is not recognized.
Makefile:501: recipe for target '_powisf2.o' failed