Re: [PATCH 2/4][ARM] Add feature set definitions.

[Matthew Wahab <matthew dot wahab at foss dot arm dot com>]

Ping. Updated patch attached.

Also, retested the series for arm-none-linux-gnueabihf with native bootstrap and
make check and arm-none-eabi with cross-compiled make check.


On 22/06/15 16:45, Matthew Wahab wrote:
> Hello,
>
> The ARM backend uses an unsigned long to record CPU feature flags and there are
> currently 30 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 by building with no errors. Also tested as part of the series, for
> arm-none-linux-gnueabihf with check-gcc.
>
> Ok for trunk?
> Matthew
>
> gcc/
> 2015-06-22  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_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 f977c65b06b0a55a6d371004d0cc64ba216ee954 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 2/4] Add feature set definitions.

Change-Id: I5f89b46ea57e35f477ec4751fea3cb6ee8fce251
---
 gcc/config/arm/arm-protos.h | 101 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index 62f91ef..a19d54d 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 */
@@ -412,6 +414,105 @@ 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] & (F)) == F)
+#define ARM_FSET_HAS_CPU2(A, F)  (((A).cpu[1] & (F)) == F)
+
+/* 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