Re: [PATCH V2] improve bitmap / sbitmap compatability of bitmap_set_bit

[Richard Biener]

On July 24, 2017 7:05:14 PM GMT+02:00, tbsaunde+...@tbsaunde.org wrote:
>From: Trevor Saunders 
>
>This makes the sbitmap version return true if the bit was previously
>unset to make it similar to the bitmap version.
>
>I believe I fixed up the comments from may, and rebootstrapped +
>regtested
>ppc64le-linux-gnu, ok?

OK.  I believe there are quite some cases that can be simplified now from 
test+set to set and return value test.

Richard.

>Trev
>
>gcc/ChangeLog:
>
>2017-07-20  Trevor Saunders  
>
>   * sbitmap.h (bitmap_set_bit): Return bool similar to bitmap
>   version of this function.
>---
> gcc/ChangeLog |  5 +
> gcc/sbitmap.h | 12 
> 2 files changed, 13 insertions(+), 4 deletions(-)
>
>diff --git a/gcc/ChangeLog b/gcc/ChangeLog
>index ef0e7881073..8d171b1a8a5 100644
>--- a/gcc/ChangeLog
>+++ b/gcc/ChangeLog
>@@ -1,3 +1,8 @@
>+2017-07-20  Trevor Saunders  
>+
>+  * sbitmap.h (bitmap_set_bit): Return bool similar to bitmap
>+  version of this function.
>+
> 2017-07-18  Uros Bizjak  
> 
>   PR target/81471
>diff --git a/gcc/sbitmap.h b/gcc/sbitmap.h
>index ce4d27d927c..6f90fc877d4 100644
>--- a/gcc/sbitmap.h
>+++ b/gcc/sbitmap.h
>@@ -104,13 +104,17 @@ bitmap_bit_p (const_sbitmap map, int bitno)
>   return (map->elms[i] >> s) & (SBITMAP_ELT_TYPE) 1;
> }
> 
>-/* Set bit number BITNO in the sbitmap MAP.  */
>+/* Set bit number BITNO in the sbitmap MAP.  Return true if it was
>+   previously unset.  */
> 
>-static inline void
>+static inline bool
> bitmap_set_bit (sbitmap map, int bitno)
> {
>-  map->elms[bitno / SBITMAP_ELT_BITS]
>-|= (SBITMAP_ELT_TYPE) 1 << (bitno) % SBITMAP_ELT_BITS;
>+  SBITMAP_ELT_TYPE *word = >elms[bitno / SBITMAP_ELT_BITS];
>+  SBITMAP_ELT_TYPE mask = (SBITMAP_ELT_TYPE) 1 << (bitno) %
>SBITMAP_ELT_BITS;
>+  bool ret = (*word & mask) == 0;
>+  *word |= mask;
>+  return ret;
> }
> 
> /* Reset bit number BITNO in the sbitmap MAP.  */

[PATCH V2] improve bitmap / sbitmap compatability of bitmap_set_bit

[tbsaunde+gcc]

From: Trevor Saunders 

This makes the sbitmap version return true if the bit was previously
unset to make it similar to the bitmap version.

I believe I fixed up the comments from may, and rebootstrapped + regtested
ppc64le-linux-gnu, ok?

Trev

gcc/ChangeLog:

2017-07-20  Trevor Saunders  

* sbitmap.h (bitmap_set_bit): Return bool similar to bitmap
version of this function.
---
 gcc/ChangeLog |  5 +
 gcc/sbitmap.h | 12 
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ef0e7881073..8d171b1a8a5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-07-20  Trevor Saunders  
+
+   * sbitmap.h (bitmap_set_bit): Return bool similar to bitmap
+   version of this function.
+
 2017-07-18  Uros Bizjak  
 
PR target/81471
diff --git a/gcc/sbitmap.h b/gcc/sbitmap.h
index ce4d27d927c..6f90fc877d4 100644
--- a/gcc/sbitmap.h
+++ b/gcc/sbitmap.h
@@ -104,13 +104,17 @@ bitmap_bit_p (const_sbitmap map, int bitno)
   return (map->elms[i] >> s) & (SBITMAP_ELT_TYPE) 1;
 }
 
-/* Set bit number BITNO in the sbitmap MAP.  */
+/* Set bit number BITNO in the sbitmap MAP.  Return true if it was
+   previously unset.  */
 
-static inline void
+static inline bool
 bitmap_set_bit (sbitmap map, int bitno)
 {
-  map->elms[bitno / SBITMAP_ELT_BITS]
-|= (SBITMAP_ELT_TYPE) 1 << (bitno) % SBITMAP_ELT_BITS;
+  SBITMAP_ELT_TYPE *word = >elms[bitno / SBITMAP_ELT_BITS];
+  SBITMAP_ELT_TYPE mask = (SBITMAP_ELT_TYPE) 1 << (bitno) % SBITMAP_ELT_BITS;
+  bool ret = (*word & mask) == 0;
+  *word |= mask;
+  return ret;
 }
 
 /* Reset bit number BITNO in the sbitmap MAP.  */
-- 
2.11.0