Patchwork [RFC] LONGEST and ULONGEST function template instantiation

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Submitter Yao Qi
Date June 15, 2017, 11:59 a.m.
Message ID <8660fxv4vi.fsf@gmail.com>
Download mbox | patch
Permalink /patch/21034/
State New
Headers show

Comments

Yao Qi - June 15, 2017, 11:59 a.m.
Pedro Alves <palves@redhat.com> writes:

Hi Pedro,
I pick up your patch, and update the ChangeLog entry.

> The version below has no impact on code size:
>
> $ size gdb.before gdb.after
>    text    data     bss     dec     hex filename
> 7535236  125008  181184 7841428  77a694 gdb.before
> 7535236  125008  181184 7841428  77a694 gdb.after

I can't reproduce your result with gcc 5.4.0 on Ubuntu 16.04.  The
patched GDB size increased by 112, but it doesn't matter.

before:
$ size ./gdb
   text	   data	    bss	    dec	    hex	filename
7733505	 144208	 180768	8058481	 7af671	./gdb

after:
$ size ./gdb
   text    data     bss     dec     hex filename
7733617  144208  180768 8058593  7af6e1 ./gdb
Pedro Alves - June 15, 2017, 4:19 p.m.
On 06/15/2017 12:59 PM, Yao Qi wrote:
> Pedro Alves <palves@redhat.com> writes:
> 
> Hi Pedro,
> I pick up your patch, and update the ChangeLog entry.

Thanks.  FAOD, fine with me to push it in.

>> The version below has no impact on code size:
>>
>> $ size gdb.before gdb.after
>>    text    data     bss     dec     hex filename
>> 7535236  125008  181184 7841428  77a694 gdb.before
>> 7535236  125008  181184 7841428  77a694 gdb.after
> 
> I can't reproduce your result with gcc 5.4.0 on Ubuntu 16.04.  The
> patched GDB size increased by 112, but it doesn't matter.
> 
> before:
> $ size ./gdb
>    text	   data	    bss	    dec	    hex	filename
> 7733505	 144208	 180768	8058481	 7af671	./gdb
> 
> after:
> $ size ./gdb
>    text    data     bss     dec     hex filename
> 7733617  144208  180768 8058593  7af6e1 ./gdb

Curious, I see the same too now.  Dunno what I did
before.

Diffing "size -A" (and stripping addr column) shows:

-gdb.before.stripped  :
+gdb.after.stripped  :
 .rela.plt              16344
 .init                     26
 .plt                   10912
-.text                4239945
+.text                4239705
 .fini                      9
-.rodata              2280312
+.rodata              2280728
 .stapsdt.base              1
-.eh_frame_hdr         126004
-.eh_frame             745124
+.eh_frame_hdr         125996
+.eh_frame             745084


So it results in less code after all.  The increase is
in .rodata.  Maybe the result of longer mangled names or
longer strings for __FUNCTION__.

Thanks,
Pedro Alves
Yao Qi - June 16, 2017, 2:45 p.m.
On Thu, Jun 15, 2017 at 5:19 PM, Pedro Alves <palves@redhat.com> wrote:
> On 06/15/2017 12:59 PM, Yao Qi wrote:
>> Pedro Alves <palves@redhat.com> writes:
>>
>> Hi Pedro,
>> I pick up your patch, and update the ChangeLog entry.
>
> Thanks.  FAOD, fine with me to push it in.
>

Patch is pushed in.

Patch

diff --git a/gdb/defs.h b/gdb/defs.h
index a1a97bb..55d16d1 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -82,6 +82,11 @@  enum compile_i_scope_types
     COMPILE_I_PRINT_VALUE_SCOPE,
   };
 
+
+template<typename T>
+using RequireLongest = gdb::Requires<gdb::Or<std::is_same<T, LONGEST>,
+					     std::is_same<T, ULONGEST>>>;
+
 /* Just in case they're not defined in stdio.h.  */
 
 #ifndef SEEK_SET
@@ -637,11 +642,22 @@  enum { MAX_REGISTER_SIZE = 64 };
 
 /* In findvar.c.  */
 
-extern LONGEST extract_signed_integer (const gdb_byte *, int,
-				       enum bfd_endian);
+template<typename T, typename = RequireLongest<T>>
+T extract_integer (const gdb_byte *addr, int len, enum bfd_endian byte_order);
 
-extern ULONGEST extract_unsigned_integer (const gdb_byte *, int,
-					  enum bfd_endian);
+static inline LONGEST
+extract_signed_integer (const gdb_byte *addr, int len,
+			enum bfd_endian byte_order)
+{
+  return extract_integer<LONGEST> (addr, len, byte_order);
+}
+
+static inline ULONGEST
+extract_unsigned_integer (const gdb_byte *addr, int len,
+			  enum bfd_endian byte_order)
+{
+  return extract_integer<ULONGEST> (addr, len, byte_order);
+}
 
 extern int extract_long_unsigned_integer (const gdb_byte *, int,
 					  enum bfd_endian, LONGEST *);
@@ -649,11 +665,26 @@  extern int extract_long_unsigned_integer (const gdb_byte *, int,
 extern CORE_ADDR extract_typed_address (const gdb_byte *buf,
 					struct type *type);
 
-extern void store_signed_integer (gdb_byte *, int,
-				  enum bfd_endian, LONGEST);
+/* All 'store' functions accept a host-format integer and store a
+   target-format integer at ADDR which is LEN bytes long.  */
 
-extern void store_unsigned_integer (gdb_byte *, int,
-				    enum bfd_endian, ULONGEST);
+template<typename T, typename = RequireLongest<T>>
+extern void store_integer (gdb_byte *addr, int len, enum bfd_endian byte_order,
+			   T val);
+
+static inline void
+store_signed_integer (gdb_byte *addr, int len,
+		      enum bfd_endian byte_order, LONGEST val)
+{
+  return store_integer (addr, len, byte_order, val);
+}
+
+static inline void
+store_unsigned_integer (gdb_byte *addr, int len,
+			enum bfd_endian byte_order, ULONGEST val)
+{
+  return store_integer (addr, len, byte_order, val);
+}
 
 extern void store_typed_address (gdb_byte *buf, struct type *type,
 				 CORE_ADDR addr);
diff --git a/gdb/findvar.c b/gdb/findvar.c
index 6c18e25..beb127e 100644
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -47,70 +47,54 @@ 
 you lose
 #endif
 
-LONGEST
-extract_signed_integer (const gdb_byte *addr, int len,
-			enum bfd_endian byte_order)
+template<typename T, typename>
+T
+extract_integer (const gdb_byte *addr, int len, enum bfd_endian byte_order)
 {
-  LONGEST retval;
+  T retval = 0;
   const unsigned char *p;
   const unsigned char *startaddr = addr;
   const unsigned char *endaddr = startaddr + len;
 
-  if (len > (int) sizeof (LONGEST))
+  if (len > (int) sizeof (T))
     error (_("\
 That operation is not available on integers of more than %d bytes."),
-	   (int) sizeof (LONGEST));
+	   (int) sizeof (T));
 
   /* Start at the most significant end of the integer, and work towards
      the least significant.  */
   if (byte_order == BFD_ENDIAN_BIG)
     {
       p = startaddr;
-      /* Do the sign extension once at the start.  */
-      retval = ((LONGEST) * p ^ 0x80) - 0x80;
-      for (++p; p < endaddr; ++p)
+      if (std::is_signed<T>::value)
+	{
+	  /* Do the sign extension once at the start.  */
+	  retval = ((LONGEST) * p ^ 0x80) - 0x80;
+	  ++p;
+	}
+      for (; p < endaddr; ++p)
 	retval = (retval << 8) | *p;
     }
   else
     {
       p = endaddr - 1;
-      /* Do the sign extension once at the start.  */
-      retval = ((LONGEST) * p ^ 0x80) - 0x80;
-      for (--p; p >= startaddr; --p)
+      if (std::is_signed<T>::value)
+	{
+	  /* Do the sign extension once at the start.  */
+	  retval = ((LONGEST) * p ^ 0x80) - 0x80;
+	  --p;
+	}
+      for (; p >= startaddr; --p)
 	retval = (retval << 8) | *p;
     }
   return retval;
 }
 
-ULONGEST
-extract_unsigned_integer (const gdb_byte *addr, int len,
-			  enum bfd_endian byte_order)
-{
-  ULONGEST retval;
-  const unsigned char *p;
-  const unsigned char *startaddr = addr;
-  const unsigned char *endaddr = startaddr + len;
-
-  if (len > (int) sizeof (ULONGEST))
-    error (_("\
-That operation is not available on integers of more than %d bytes."),
-	   (int) sizeof (ULONGEST));
-
-  /* Start at the most significant end of the integer, and work towards
-     the least significant.  */
-  retval = 0;
-  if (byte_order == BFD_ENDIAN_BIG)
-    {
-      for (p = startaddr; p < endaddr; ++p)
-	retval = (retval << 8) | *p;
-    }
-  else
-    {
-      for (p = endaddr - 1; p >= startaddr; --p)
-	retval = (retval << 8) | *p;
-    }
-  return retval;
-}
+/* Explicit instantiations.  */
+template LONGEST extract_integer<LONGEST> (const gdb_byte *addr, int len,
+					   enum bfd_endian byte_order);
+template ULONGEST extract_integer<ULONGEST> (const gdb_byte *addr, int len,
+					     enum bfd_endian byte_order);
 
 /* Sometimes a long long unsigned integer can be extracted as a
    LONGEST value.  This is done so that we can print these values
@@ -180,10 +164,10 @@  extract_typed_address (const gdb_byte *buf, struct type *type)
 
 /* All 'store' functions accept a host-format integer and store a
    target-format integer at ADDR which is LEN bytes long.  */
-
+template<typename T, typename>
 void
-store_signed_integer (gdb_byte *addr, int len,
-		      enum bfd_endian byte_order, LONGEST val)
+store_integer (gdb_byte *addr, int len, enum bfd_endian byte_order,
+	       T val)
 {
   gdb_byte *p;
   gdb_byte *startaddr = addr;
@@ -209,33 +193,14 @@  store_signed_integer (gdb_byte *addr, int len,
     }
 }
 
-void
-store_unsigned_integer (gdb_byte *addr, int len,
-			enum bfd_endian byte_order, ULONGEST val)
-{
-  unsigned char *p;
-  unsigned char *startaddr = (unsigned char *) addr;
-  unsigned char *endaddr = startaddr + len;
+/* Explicit instantiations.  */
+template void store_integer (gdb_byte *addr, int len,
+			     enum bfd_endian byte_order,
+			     LONGEST val);
 
-  /* Start at the least significant end of the integer, and work towards
-     the most significant.  */
-  if (byte_order == BFD_ENDIAN_BIG)
-    {
-      for (p = endaddr - 1; p >= startaddr; --p)
-	{
-	  *p = val & 0xff;
-	  val >>= 8;
-	}
-    }
-  else
-    {
-      for (p = startaddr; p < endaddr; ++p)
-	{
-	  *p = val & 0xff;
-	  val >>= 8;
-	}
-    }
-}
+template void store_integer (gdb_byte *addr, int len,
+			     enum bfd_endian byte_order,
+			     ULONGEST val);
 
 /* Store the address ADDR as a pointer of type TYPE at BUF, in target
    form.  */
diff --git a/gdb/regcache.c b/gdb/regcache.c
index 43ea430..7eeb737 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -662,11 +662,12 @@  enum register_status
 regcache_raw_read_signed (struct regcache *regcache, int regnum, LONGEST *val)
 {
   gdb_assert (regcache != NULL);
-  return regcache->raw_read_signed (regnum, val);
+  return regcache->raw_read (regnum, val);
 }
 
+template<typename T, typename>
 enum register_status
-regcache::raw_read_signed (int regnum, LONGEST *val)
+regcache::raw_read (int regnum, T *val)
 {
   gdb_byte *buf;
   enum register_status status;
@@ -675,9 +676,9 @@  regcache::raw_read_signed (int regnum, LONGEST *val)
   buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
   status = raw_read (regnum, buf);
   if (status == REG_VALID)
-    *val = extract_signed_integer
-      (buf, m_descr->sizeof_register[regnum],
-       gdbarch_byte_order (m_descr->gdbarch));
+    *val = extract_integer<T> (buf,
+			       m_descr->sizeof_register[regnum],
+			       gdbarch_byte_order (m_descr->gdbarch));
   else
     *val = 0;
   return status;
@@ -688,44 +689,26 @@  regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
 			    ULONGEST *val)
 {
   gdb_assert (regcache != NULL);
-  return regcache->raw_read_unsigned (regnum, val);
-}
-
-
-enum register_status
-regcache::raw_read_unsigned (int regnum, ULONGEST *val)
-{
-  gdb_byte *buf;
-  enum register_status status;
-
-  gdb_assert (regnum >= 0 && regnum < m_descr->nr_raw_registers);
-  buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
-  status = raw_read (regnum, buf);
-  if (status == REG_VALID)
-    *val = extract_unsigned_integer
-      (buf, m_descr->sizeof_register[regnum],
-       gdbarch_byte_order (m_descr->gdbarch));
-  else
-    *val = 0;
-  return status;
+  return regcache->raw_read (regnum, val);
 }
 
 void
 regcache_raw_write_signed (struct regcache *regcache, int regnum, LONGEST val)
 {
   gdb_assert (regcache != NULL);
-  regcache->raw_write_signed (regnum, val);
+  regcache->raw_write (regnum, val);
 }
 
+template<typename T, typename>
 void
-regcache::raw_write_signed (int regnum, LONGEST val)
+regcache::raw_write (int regnum, T val)
 {
   gdb_byte *buf;
 
   gdb_assert (regnum >=0 && regnum < m_descr->nr_raw_registers);
   buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
-  store_signed_integer (buf, m_descr->sizeof_register[regnum],
-			gdbarch_byte_order (m_descr->gdbarch), val);
+  store_integer (buf, m_descr->sizeof_register[regnum],
+		 gdbarch_byte_order (m_descr->gdbarch), val);
   raw_write (regnum, buf);
 }
 
@@ -734,19 +717,7 @@  regcache_raw_write_unsigned (struct regcache *regcache, int regnum,
 			     ULONGEST val)
 {
   gdb_assert (regcache != NULL);
-  regcache->raw_write_unsigned (regnum, val);
-}
-
-void
-regcache::raw_write_unsigned (int regnum, ULONGEST val)
-{
-  gdb_byte *buf;
-
-  gdb_assert (regnum >=0 && regnum < m_descr->nr_raw_registers);
-  buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
-  store_unsigned_integer (buf, m_descr->sizeof_register[regnum],
-			  gdbarch_byte_order (m_descr->gdbarch), val);
-  raw_write (regnum, buf);
+  regcache->raw_write (regnum, val);
 }
 
 LONGEST
@@ -857,11 +828,12 @@  regcache_cooked_read_signed (struct regcache *regcache, int regnum,
 			     LONGEST *val)
 {
   gdb_assert (regcache != NULL);
-  return regcache->cooked_read_signed (regnum, val);
+  return regcache->cooked_read (regnum, val);
 }
 
+template<typename T, typename>
 enum register_status
-regcache::cooked_read_signed (int regnum, LONGEST *val)
+regcache::cooked_read (int regnum, T *val)
 {
   enum register_status status;
   gdb_byte *buf;
@@ -870,9 +842,8 @@  regcache::cooked_read_signed (int regnum, LONGEST *val)
   buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
   status = cooked_read (regnum, buf);
   if (status == REG_VALID)
-    *val = extract_signed_integer
-      (buf, m_descr->sizeof_register[regnum],
-       gdbarch_byte_order (m_descr->gdbarch));
+    *val = extract_integer<T> (buf, m_descr->sizeof_register[regnum],
+			       gdbarch_byte_order (m_descr->gdbarch));
   else
     *val = 0;
   return status;
@@ -883,25 +854,7 @@  regcache_cooked_read_unsigned (struct regcache *regcache, int regnum,
 			       ULONGEST *val)
 {
   gdb_assert (regcache != NULL);
-  return regcache->cooked_read_unsigned (regnum, val);
-}
-
-enum register_status
-regcache::cooked_read_unsigned (int regnum, ULONGEST *val)
-{
-  enum register_status status;
-  gdb_byte *buf;
-
-  gdb_assert (regnum >= 0 && regnum < m_descr->nr_cooked_registers);
-  buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
-  status = cooked_read (regnum, buf);
-  if (status == REG_VALID)
-    *val = extract_unsigned_integer
-      (buf, m_descr->sizeof_register[regnum],
-       gdbarch_byte_order (m_descr->gdbarch));
-  else
-    *val = 0;
-  return status;
+  return regcache->cooked_read (regnum, val);
 }
 
 void
@@ -909,18 +862,19 @@  regcache_cooked_write_signed (struct regcache *regcache, int regnum,
 			      LONGEST val)
 {
   gdb_assert (regcache != NULL);
-  regcache->cooked_write_signed (regnum, val);
+  regcache->cooked_write (regnum, val);
 }
 
+template<typename T, typename>
 void
-regcache::cooked_write_signed (int regnum, LONGEST val)
+regcache::cooked_write (int regnum, T val)
 {
   gdb_byte *buf;
 
   gdb_assert (regnum >=0 && regnum < m_descr->nr_cooked_registers);
   buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
-  store_signed_integer (buf, m_descr->sizeof_register[regnum],
-			gdbarch_byte_order (m_descr->gdbarch), val);
+  store_integer (buf, m_descr->sizeof_register[regnum],
+		 gdbarch_byte_order (m_descr->gdbarch), val);
   cooked_write (regnum, buf);
 }
 
@@ -929,19 +883,7 @@  regcache_cooked_write_unsigned (struct regcache *regcache, int regnum,
 				ULONGEST val)
 {
   gdb_assert (regcache != NULL);
-  regcache->cooked_write_unsigned (regnum, val);
-}
-
-void
-regcache::cooked_write_unsigned (int regnum, ULONGEST val)
-{
-  gdb_byte *buf;
-
-  gdb_assert (regnum >=0 && regnum < m_descr->nr_cooked_registers);
-  buf = (gdb_byte *) alloca (m_descr->sizeof_register[regnum]);
-  store_unsigned_integer (buf, m_descr->sizeof_register[regnum],
-			  gdbarch_byte_order (m_descr->gdbarch), val);
-  cooked_write (regnum, buf);
+  regcache->cooked_write (regnum, val);
 }
 
 /* See regcache.h.  */
diff --git a/gdb/regcache.h b/gdb/regcache.h
index 4cf27a0..3f3f823 100644
--- a/gdb/regcache.h
+++ b/gdb/regcache.h
@@ -282,23 +282,19 @@  public:
 #endif
   void raw_write (int regnum, const gdb_byte *buf);
 
-  enum register_status raw_read_signed (int regnum, LONGEST *val);
+  template<typename T, typename = RequireLongest<T>>
+  enum register_status raw_read (int regnum, T *val);
 
-  void raw_write_signed (int regnum, LONGEST val);
-
-  enum register_status raw_read_unsigned (int regnum, ULONGEST *val);
-
-  void raw_write_unsigned (int regnum, ULONGEST val);
+  template<typename T, typename = RequireLongest<T>>
+  void raw_write (int regnum, T val);
 
   struct value *cooked_read_value (int regnum);
 
-  enum register_status cooked_read_signed (int regnum, LONGEST *val);
-
-  void cooked_write_signed (int regnum, LONGEST val);
-
-  enum register_status cooked_read_unsigned (int regnum, ULONGEST *val);
+  template<typename T, typename = RequireLongest<T>>
+  enum register_status cooked_read (int regnum, T *val);
 
-  void cooked_write_unsigned (int regnum, ULONGEST val);
+  template<typename T, typename = RequireLongest<T>>
+  void cooked_write (int regnum, T val);
 
   void raw_update (int regnum);
 
diff --git a/gdb/sh64-tdep.c b/gdb/sh64-tdep.c
index dd18e9f..5aeb235 100644
--- a/gdb/sh64-tdep.c
+++ b/gdb/sh64-tdep.c
@@ -1665,11 +1665,11 @@  sh64_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
        */
       /* *INDENT-ON* */
       /* Get FPSCR as an int.  */
-      status = regcache->raw_read_unsigned (fpscr_base_regnum, &fpscr_value);
+      status = regcache->raw_read (fpscr_base_regnum, &fpscr_value);
       if (status != REG_VALID)
 	return status;
       /* Get SR as an int.  */
-      status = regcache->raw_read_unsigned (sr_base_regnum, &sr_value);
+      status = regcache->raw_read (sr_base_regnum, &sr_value);
       if (status != REG_VALID)
 	return status;
       /* Build the new value.  */
@@ -1847,15 +1847,15 @@  sh64_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
       fpscr_value = fpscr_c_value & fpscr_mask;
       sr_value = (fpscr_value & sr_mask) >> 6;
       
-      regcache->raw_read_unsigned (fpscr_base_regnum, &old_fpscr_value);
+      regcache->raw_read (fpscr_base_regnum, &old_fpscr_value);
       old_fpscr_value &= 0xfffc0002;
       fpscr_value |= old_fpscr_value;
-      regcache->raw_write_unsigned (fpscr_base_regnum, fpscr_value);
+      regcache->raw_write (fpscr_base_regnum, fpscr_value);
 
-      regcache->raw_read_unsigned (sr_base_regnum, &old_sr_value);
+      regcache->raw_read (sr_base_regnum, &old_sr_value);
       old_sr_value &= 0xffff8fff;
       sr_value |= old_sr_value;
-      regcache->raw_write_unsigned (sr_base_regnum, sr_value);
+      regcache->raw_write (sr_base_regnum, sr_value);
     }
 
   else if (reg_nr == FPUL_C_REGNUM)