Re: [PATCH 2/5][ARM] Add feature set definitions.

[Ramana Radhakrishnan <ramana dot radhakrishnan at foss dot arm dot com>]

On Mon, Aug 10, 2015 at 12:56:59PM +0100, Matthew Wahab wrote:
> The ARM backend uses an unsigned long to record CPU feature flags and
> there are currently 31 bits in use. This series of patches replaces the
> single unsigned long with a representation based on an array of values.
> 
> This patch adds, but doesn't use, type arm_feature_set and macros
> prefixed with ARM_FSET to represent and operate on feature sets.
> 
> Tested the series for arm-none-linux-gnueabihf with native bootstrap and
> make check.
> 
> gcc/
> 2015-08-10  Matthew Wahab  <matthew.wahab@arm.com>
> 
> 	* config/arm/arm-protos.h (FL_NONE): New.
> 	(FL_ANY): New.
> 	(arm_feature_set): New.
> 	(ARM_FSET_MAKE): New.
> 	(ARM_FSET_MAKE_CPU1): New.
> 	(ARM_FSET_MAKE_CPU2): New.
> 	(ARM_FSET_CPU1): New.
> 	(ARM_FSET_CPU2): New.
> 	(ARM_FSET_EMPTY): New.
> 	(ARM_FSET_ANY): New.
> 	(ARM_FSET_HAS_CPU1): New.
> 	(ARM_FSET_HAS_CPU2): New.
> 	(ARM_FSET_HAS_CPU): New.
> 	(ARM_FSET_ADD_CPU1): New.
> 	(ARM_FSET_ADD_CPU2): New.
> 	(ARM_FSET_DEL_CPU1): New.
> 	(ARM_FSET_DEL_CPU2): New.
> 	(ARM_FSET_UNION): New.
> 	(ARM_FSET_INTER): New.
> 	(ARM_FSET_XOR): New.
> 	(ARM_FSET_EXCLUDE): New.
> 	(AFM_FSET_IS_EMPTY): New.
> 	(ARM_FSET_CPU_SUBSET): New.
> 

> From fd51de4ebdbeff478716cf0a4329fd38cd861403 Mon Sep 17 00:00:00 2001
> From: Matthew Wahab <matthew.wahab@arm.com>
> Date: Thu, 4 Jun 2015 15:35:25 +0100
> Subject: [PATCH 2/5] Add feature set definitions.
> 
> Change-Id: I5f89b46ea57e35f477ec4751fea3cb6ee8fce251
> ---
>  gcc/config/arm/arm-protos.h | 105 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 105 insertions(+)
> 
> diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
> index cef9eec..610c73e 100644
> --- a/gcc/config/arm/arm-protos.h
> +++ b/gcc/config/arm/arm-protos.h
> @@ -346,6 +346,8 @@ extern bool arm_is_constant_pool_ref (rtx);
>  /* Flags used to identify the presence of processor capabilities.  */
>  
>  /* Bit values used to identify processor capabilities.  */
> +#define FL_NONE	      (0)	      /* No flags.  */
> +#define FL_ANY	      (0xffffffff)    /* All flags.  */
>  #define FL_CO_PROC    (1 << 0)        /* Has external co-processor bus */
>  #define FL_ARCH3M     (1 << 1)        /* Extended multiply */
>  #define FL_MODE26     (1 << 2)        /* 26-bit mode support */
> @@ -413,6 +415,109 @@ extern bool arm_is_constant_pool_ref (rtx);
>  #define FL_FOR_ARCH7EM  (FL_FOR_ARCH7M | FL_ARCH7EM)
>  #define FL_FOR_ARCH8A	(FL_FOR_ARCH7VE | FL_ARCH8)
>  
> +/* There are too many feature bits to fit in a single word so the set of cpu and
> +   fpu capabilities is a structure.  A feature set is created and manipulated
> +   with the ARM_FSET macros.  */
> +
> +typedef struct
> +{
> +  unsigned long cpu[2];
> +} arm_feature_set;
> +
> +
> +/* Initialize a feature set.  */
> +
> +#define ARM_FSET_MAKE(CPU1,CPU2) { { (CPU1), (CPU2) } }
> +
> +#define ARM_FSET_MAKE_CPU1(CPU1) ARM_FSET_MAKE ((CPU1), (FL_NONE))
> +#define ARM_FSET_MAKE_CPU2(CPU2) ARM_FSET_MAKE ((FL_NONE), (CPU2))
> +
> +/* Accessors.  */
> +
> +#define ARM_FSET_CPU1(S) ((S).cpu[0])
> +#define ARM_FSET_CPU2(S) ((S).cpu[1])
> +
> +/* Useful combinations.  */
> +
> +#define ARM_FSET_EMPTY ARM_FSET_MAKE (FL_NONE, FL_NONE)
> +#define ARM_FSET_ANY ARM_FSET_MAKE (FL_ANY, FL_ANY)
> +
> +/* Tests for a specific CPU feature.  */
> +
> +#define ARM_FSET_HAS_CPU1(A, F)  \
> +  (((A).cpu[0] & ((unsigned long)(F))) == ((unsigned long)(F)))
> +#define ARM_FSET_HAS_CPU2(A, F)  \
> +  (((A).cpu[1] & ((unsigned long)(F))) == ((unsigned long)(F)))
> +#define ARM_FSET_HAS_CPU(A, F1, F2)				\
> +  (ARM_FSET_HAS_CPU1 ((A), (F1)) && ARM_FSET_HAS_CPU2 ((A), (F2)))
> +
> +/* Add a feature to a feature set.  */
> +
> +#define ARM_FSET_ADD_CPU1(DST, F)		\
> +  do {						\
> +    (DST).cpu[0] |= (F);			\
> +  } while (0)
> +
> +#define ARM_FSET_ADD_CPU2(DST, F)		\
> +  do {						\
> +    (DST).cpu[1] |= (F);			\
> +  } while (0)
> +
> +/* Remove a feature from a feature set.  */
> +
> +#define ARM_FSET_DEL_CPU1(DST, F)		\
> +  do {						\
> +    (DST).cpu[0] &= ~(F);			\
> +  } while (0)
> +
> +#define ARM_FSET_DEL_CPU2(DST, F)		\
> +  do {						\
> +    (DST).cpu[1] &= ~(F);			\
> +  } while (0)
> +
> +/* Union of feature sets.  */
> +
> +#define ARM_FSET_UNION(DST,F1,F2)		\
> +  do {						\
> +    (DST).cpu[0] = (F1).cpu[0] | (F2).cpu[0];	\
> +    (DST).cpu[1] = (F1).cpu[1] | (F2).cpu[1];	\
> +  } while (0)
> +
> +/* Intersection of feature sets.  */
> +
> +#define ARM_FSET_INTER(DST,F1,F2)		\
> +  do {						\
> +    (DST).cpu[0] = (F1).cpu[0] & (F2).cpu[0];	\
> +    (DST).cpu[1] = (F1).cpu[1] & (F2).cpu[1];	\
> +  } while (0)
> +
> +/* Exclusive disjunction.  */
> +
> +#define ARM_FSET_XOR(DST,F1,F2)				\
> +  do {							\
> +    (DST).cpu[0] = (F1).cpu[0] ^ (F2).cpu[0];		\
> +    (DST).cpu[1] = (F1).cpu[1] ^ (F2).cpu[1];		\
> +  } while (0)
> +
> +/* Difference of feature sets: F1 excluding the elements of F2.  */
> +
> +#define ARM_FSET_EXCLUDE(DST,F1,F2)		\
> +  do {						\
> +    (DST).cpu[0] = (F1).cpu[0] & ~(F2).cpu[0];	\
> +    (DST).cpu[1] = (F1).cpu[1] & ~(F2).cpu[1];	\
> +  } while (0)
> +
> +/* Test for an empty feature set.  */
> +
> +#define ARM_FSET_IS_EMPTY(A)		\
> +  (!((A).cpu[0]) && !((A).cpu[1]))
> +
> +/* Tests whether the cpu features of A are a subset of B.  */
> +
> +#define ARM_FSET_CPU_SUBSET(A,B)					\
> +  ((((A).cpu[0] & (B).cpu[0]) == (A).cpu[0])				\
> +   && (((A).cpu[1] & (B).cpu[1]) == (A).cpu[1]))
> +
>  /* The bits in this mask specify which
>     instructions we are allowed to generate.  */
>  extern unsigned long insn_flags;
> -- 
> 1.9.1
> 


OK.

Ramana