diff mbox series

[18/19] Use gdb unordered map in tui-io.c

Message ID 20250317-replace-std-stuff-v1-18-7ba4ee88e218@tromey.com
State New
Headers
Series Convert std::unordered_{set,map} to gdb implementations |

Checks

Context Check Description
linaro-tcwg-bot/tcwg_gdb_build--master-aarch64 fail Patch failed to apply
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Commit Message

Tom Tromey March 18, 2025, 2:15 a.m. UTC 
  This changes tui.c to use gdb::unordered_map.  ui_file_style::color is
changed a little as well; operator< is no longer needed, but a simple
hash function is added.
---
 gdb/tui/tui-io.c | 37 ++++++++++++++++++++++++++++++++-----
 gdb/ui-style.h   | 18 ++++--------------
 2 files changed, 36 insertions(+), 19 deletions(-)

Comments

Simon Marchi March 18, 2025, 3:26 a.m. UTC | #1 
On 2025-03-17 22:15, Tom Tromey wrote:
> This changes tui.c to use gdb::unordered_map.  ui_file_style::color is
> changed a little as well; operator< is no longer needed, but a simple
> hash function is added.
> ---
>  gdb/tui/tui-io.c | 37 ++++++++++++++++++++++++++++++++-----
>  gdb/ui-style.h   | 18 ++++--------------
>  2 files changed, 36 insertions(+), 19 deletions(-)
> 
> diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c
> index 7013a543ab61f268e06e78ccad52aa5cc8419700..5d012b2e2077c8c8bd710f5694b0fcd7061b23ea 100644
> --- a/gdb/tui/tui-io.c
> +++ b/gdb/tui/tui-io.c
> @@ -42,7 +42,7 @@
>  #include "gdbsupport/filestuff.h"
>  #include "completer.h"
>  #include "gdb_curses.h"
> -#include <map>
> +#include "gdbsupport/unordered_map.h"
>  #include "pager.h"
>  #include "gdbsupport/gdb-checked-static-cast.h"
>  
> @@ -178,9 +178,25 @@ tui_putc (char c)
>    update_cmdwin_start_line ();
>  }
>  
> +/* Specialization of std::hash for colors.  */
> +
> +namespace std
> +{
> +template<> struct hash<ui_file_style::color>
> +{
> +  typedef ui_file_style::color argument_type;
> +  typedef std::size_t result_type;
> +
> +  result_type operator() (const argument_type &color) const noexcept
> +  {
> +    return color.hash ();
> +  }
> +};
> +}

I'm just curious to know why you decided to specialize std::hash here
instead of defining a custom hash type as we do elsewhere.

Simon
Tom Tromey March 18, 2025, 11:34 a.m. UTC | #2 
>>>>> "Simon" == Simon Marchi <simark@simark.ca> writes:

Simon> I'm just curious to know why you decided to specialize std::hash here
Simon> instead of defining a custom hash type as we do elsewhere.

No good reason.  I changed it in v2.

Tom
diff mbox series

Patch

diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c
index 7013a543ab61f268e06e78ccad52aa5cc8419700..5d012b2e2077c8c8bd710f5694b0fcd7061b23ea 100644
--- a/gdb/tui/tui-io.c
+++ b/gdb/tui/tui-io.c
@@ -42,7 +42,7 @@ 
 #include "gdbsupport/filestuff.h"
 #include "completer.h"
 #include "gdb_curses.h"
-#include <map>
+#include "gdbsupport/unordered_map.h"
 #include "pager.h"
 #include "gdbsupport/gdb-checked-static-cast.h"
 
@@ -178,9 +178,25 @@  tui_putc (char c)
   update_cmdwin_start_line ();
 }
 
+/* Specialization of std::hash for colors.  */
+
+namespace std
+{
+template<> struct hash<ui_file_style::color>
+{
+  typedef ui_file_style::color argument_type;
+  typedef std::size_t result_type;
+
+  result_type operator() (const argument_type &color) const noexcept
+  {
+    return color.hash ();
+  }
+};
+}
+
 /* This maps colors to their corresponding color index.  */
 
-static std::map<ui_file_style::color, int> color_map;
+static gdb::unordered_map<ui_file_style::color, int> color_map;
 
 /* This holds a pair of colors and is used to track the mapping
    between a color pair index and the actual colors.  */
@@ -190,16 +206,27 @@  struct color_pair
   int fg;
   int bg;
 
-  bool operator< (const color_pair &o) const
+  bool operator== (const color_pair &other) const noexcept
+  {
+    return fg == other.fg && bg == other.bg;
+  }
+};
+
+struct color_pair_hash
+{
+  using is_avalanching = void;
+
+  size_t operator() (const color_pair &val) const noexcept
   {
-    return fg < o.fg || (fg == o.fg && bg < o.bg);
+    static_assert (std::has_unique_object_representations_v<color_pair>);
+    return ankerl::unordered_dense::detail::wyhash::hash (&val, sizeof (val));
   }
 };
 
 /* This maps pairs of colors to their corresponding color pair
    index.  */
 
-static std::map<color_pair, int> color_pair_map;
+static gdb::unordered_map<color_pair, int, color_pair_hash> color_pair_map;
 
 /* This is indexed by ANSI color offset from the base color, and holds
    the corresponding curses color constant.  */
diff --git a/gdb/ui-style.h b/gdb/ui-style.h
index d814588254143149e5b24a45f3a3cdd8a24c91da..4e994966e27c582335952f58c33887fc7c0b0b86 100644
--- a/gdb/ui-style.h
+++ b/gdb/ui-style.h
@@ -151,22 +151,12 @@  struct ui_file_style
       return ! (*this == other);
     }
 
-    bool operator< (const color &other) const
+    /* Compute a simple hash code for this object.  */
+    size_t hash () const
     {
-      if (m_color_space != other.m_color_space)
-	return m_color_space < other.m_color_space;
       if (is_simple ())
-	return m_value < other.m_value;
-      if (m_red < other.m_red)
-	return true;
-      if (m_red == other.m_red)
-	{
-	  if (m_green < other.m_green)
-	    return true;
-	  if (m_green == other.m_green)
-	    return m_blue < other.m_blue;
-	}
-      return false;
+	return m_value;
+      return (m_red << 16) + (m_green << 8) + m_red;
     }
 
     color_space colorspace () const