[PATCH 0/1] ppc: support register names in macros

[PATCH 0/1] ppc: support register names in macros

[Dmitry Selyutin]

This patch is a follow-up of discussion:

https://sourceware.org/pipermail/binutils/2022-July/121719.html

Form now on, PPC assembly becomes capable of compiling such code:

    .set VREG, %r0
    .set REG, VREG
    extsw REG, 2  
    extsw %r1, 1

The custom register_name() code path, as well as checks for CRs, are
deprecated; from now on, we use md_operand() routine everywhere.

Whilst we're here, let's also reuse register lookup for CFI.

Dmitry Selyutin (1):
  ppc: support register names in macros

 gas/config/tc-ppc.c | 206 +++++++++++++++++---------------------------
 gas/config/tc-ppc.h |   9 +-
 2 files changed, 86 insertions(+), 129 deletions(-)

-- 
2.37.0

[PATCH 1/1] ppc: support register names in macros

[Dmitry Selyutin]

This patch is a follow-up of discussion:

https://sourceware.org/pipermail/binutils/2022-July/121719.html

Form now on, PPC assembly becomes capable of compiling such code:

    .set VREG, %r0
    .set REG, VREG
    extsw REG, 2
    extsw %r1, 1

The custom register_name() code path, as well as checks for CRs, are
deprecated; from now on, we use md_operand() routine everywhere.

Whilst we're here, let's also reuse register lookup for CFI.
---
 gas/config/tc-ppc.c | 206 +++++++++++++++++---------------------------
 gas/config/tc-ppc.h |   9 +-
 2 files changed, 86 insertions(+), 129 deletions(-)

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index ac61cd8f12..0b814c4873 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -317,7 +317,7 @@ struct pd_reg
 
    The table is sorted. Suitable for searching by a binary search.  */
 
-static const struct pd_reg pre_defined_registers[] =
+static const struct pd_reg reg_names[] =
 {
   /* VSX accumulators.  */
   { "a0", 0, PPC_OPERAND_ACC },
@@ -784,8 +784,25 @@ static const struct pd_reg pre_defined_registers[] =
 
   { "xer", 1, PPC_OPERAND_SPR }
 };
+#define REG_NAME_CNT	(sizeof (reg_names) / sizeof (struct pd_reg))
 
-#define REG_NAME_CNT	(sizeof (pre_defined_registers) / sizeof (struct pd_reg))
+static const struct pd_reg cr_names[] =
+{
+  { "cr0", 0, PPC_OPERAND_CR_REG },
+  { "cr1", 1, PPC_OPERAND_CR_REG },
+  { "cr2", 2, PPC_OPERAND_CR_REG },
+  { "cr3", 3, PPC_OPERAND_CR_REG },
+  { "cr4", 4, PPC_OPERAND_CR_REG },
+  { "cr5", 5, PPC_OPERAND_CR_REG },
+  { "cr6", 6, PPC_OPERAND_CR_REG },
+  { "cr7", 7, PPC_OPERAND_CR_REG },
+  { "eq", 2, PPC_OPERAND_CR_BIT },
+  { "gt", 1, PPC_OPERAND_CR_BIT },
+  { "lt", 0, PPC_OPERAND_CR_BIT },
+  { "so", 3, PPC_OPERAND_CR_BIT },
+  { "un", 3, PPC_OPERAND_CR_BIT }
+};
+#define CR_NAME_CNT	(sizeof (cr_names) / sizeof (struct pd_reg))
 
 /* Given NAME, find the register number associated with that name, return
    the integer value associated with the given name or -1 on failure.  */
@@ -815,106 +832,68 @@ reg_name_search (const struct pd_reg *regs, int regcount, const char *name)
   return NULL;
 }
 
-/*
- * Summary of register_name.
- *
- * in:	Input_line_pointer points to 1st char of operand.
- *
- * out:	A expressionS.
- *      The operand may have been a register: in this case, X_op == O_register,
- *      X_add_number is set to the register number, and truth is returned.
- *	Input_line_pointer->(next non-blank) char after operand, or is in its
- *      original state.
- */
+\f
+static bool cr_operand;
 
-static bool
-register_name (expressionS *expressionP)
+int
+ppc_parse_name (const char *name, expressionS *exp)
 {
+  symbolS *symbol;
   const struct pd_reg *reg;
-  char *name;
-  char *start;
-  char c;
 
   /* Find the spelling of the operand.  */
-  start = name = input_line_pointer;
   if (name[0] == '%' && ISALPHA (name[1]))
-    name = ++input_line_pointer;
-
-  else if (!reg_names_p || !ISALPHA (name[0]))
-    return false;
-
-  c = get_symbol_name (&name);
-  reg = reg_name_search (pre_defined_registers, REG_NAME_CNT, name);
-
-  /* Put back the delimiting char.  */
-  *input_line_pointer = c;
+    ++name;
+  else if (!cr_operand && (!reg_names_p || !ISALPHA (name[0])))
+    return 0;
 
   /* Look to see if it's in the register table.  */
+  if (cr_operand)
+    reg = reg_name_search (cr_names, CR_NAME_CNT, name);
+  else
+    reg = reg_name_search (reg_names, REG_NAME_CNT, name);
   if (reg != NULL)
     {
-      expressionP->X_op = O_register;
-      expressionP->X_add_number = reg->value;
-      expressionP->X_md = reg->flags;
+      exp->X_op = O_register;
+      exp->X_add_number = reg->value;
+      exp->X_md = reg->flags;
 
-      /* Make the rest nice.  */
-      expressionP->X_add_symbol = NULL;
-      expressionP->X_op_symbol = NULL;
-      return true;
-    }
+      if (! cr_operand)
+	{
+	  /* Make the rest nice.  */
+	  exp->X_add_symbol = NULL;
+	  exp->X_op_symbol = NULL;
+	}
 
-  /* Reset the line as if we had not done anything.  */
-  input_line_pointer = start;
-  return false;
-}
-\f
-/* This function is called for each symbol seen in an expression.  It
-   handles the special parsing which PowerPC assemblers are supposed
-   to use for condition codes.  */
+      return 1;
+    }
 
-/* Whether to do the special parsing.  */
-static bool cr_operand;
+  /* Look to see if it's a macro.  */
+  symbol = symbol_find_or_make (name);
+  if (symbol != NULL)
+    {
+      expressionS symbol_exp = *symbol_get_value_expression (symbol);
 
-/* Names to recognize in a condition code.  This table is sorted.  */
-static const struct pd_reg cr_names[] =
-{
-  { "cr0", 0, PPC_OPERAND_CR_REG },
-  { "cr1", 1, PPC_OPERAND_CR_REG },
-  { "cr2", 2, PPC_OPERAND_CR_REG },
-  { "cr3", 3, PPC_OPERAND_CR_REG },
-  { "cr4", 4, PPC_OPERAND_CR_REG },
-  { "cr5", 5, PPC_OPERAND_CR_REG },
-  { "cr6", 6, PPC_OPERAND_CR_REG },
-  { "cr7", 7, PPC_OPERAND_CR_REG },
-  { "eq", 2, PPC_OPERAND_CR_BIT },
-  { "gt", 1, PPC_OPERAND_CR_BIT },
-  { "lt", 0, PPC_OPERAND_CR_BIT },
-  { "so", 3, PPC_OPERAND_CR_BIT },
-  { "un", 3, PPC_OPERAND_CR_BIT }
-};
+      if ((symbol_exp.X_op == O_register)
+		|| (symbol_exp.X_op == O_constant))
+	{
+	  *exp = symbol_exp;
+	  return 1;
+	}
+    }
 
-/* Parsing function.  This returns non-zero if it recognized an
-   expression.  */
+  return 0;
+}
 
-int
-ppc_parse_name (const char *name, expressionS *exp)
+void
+ppc_operand (expressionS *exp)
 {
-  const struct pd_reg *reg;
-
-  if (! cr_operand)
-    return 0;
-
-  if (*name == '%')
-    ++name;
-  reg = reg_name_search (cr_names, sizeof cr_names / sizeof cr_names[0],
-			 name);
-  if (reg == NULL)
-    return 0;
-
-  exp->X_op = O_register;
-  exp->X_add_number = reg->value;
-  exp->X_md = reg->flags;
+  char endc;
+  char *name = input_line_pointer;
 
-  return 1;
+  endc = get_symbol_name (&name);
+  if (!ppc_parse_name (name, exp))
+    restore_line_pointer (endc);
 }
 
 /* Propagate X_md and check register expressions.  This is to support
@@ -3276,7 +3255,6 @@ parse_tls_arg (char **str, const expressionS *exp, struct ppc_fixup *tls_fix)
 #endif
 
 /* This routine is called for each instruction to be assembled.  */
-
 void
 md_assemble (char *str)
 {
@@ -3439,25 +3417,11 @@ md_assemble (char *str)
       /* Gather the operand.  */
       hold = input_line_pointer;
       input_line_pointer = str;
-
-      if ((reg_names_p
-	   && (((operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	       || ((operand->flags & PPC_OPERAND_CR_REG) != 0)))
-	  || !register_name (&ex))
-	{
-	  char save_lex = lex_type['%'];
-
-	  if (((operand->flags & PPC_OPERAND_CR_REG) != 0)
-	      || (operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	    {
-	      cr_operand = true;
-	      lex_type['%'] |= LEX_BEGIN_NAME;
-	    }
-	  expression (&ex);
-	  cr_operand = false;
-	  lex_type['%'] = save_lex;
-	}
-
+      memset (&ex, 0, sizeof (expressionS));
+      if (operand->flags & (PPC_OPERAND_CR_BIT | PPC_OPERAND_CR_REG))
+	cr_operand = true;
+      expression (&ex);
+      cr_operand = false;
       str = input_line_pointer;
       input_line_pointer = hold;
 
@@ -7736,10 +7700,8 @@ ppc_cfi_frame_initial_instructions (void)
 int
 tc_ppc_regname_to_dw2regnum (char *regname)
 {
-  unsigned int regnum = -1;
   unsigned int i;
-  const char *p;
-  char *q;
+  const struct pd_reg *reg;
   static struct { const char *name; int dw2regnum; } regnames[] =
     {
       { "sp", 1 }, { "r.sp", 1 }, { "rtoc", 2 }, { "r.toc", 2 },
@@ -7752,23 +7714,15 @@ tc_ppc_regname_to_dw2regnum (char *regname)
     if (strcmp (regnames[i].name, regname) == 0)
       return regnames[i].dw2regnum;
 
-  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
-    {
-      p = regname + 1 + (regname[1] == '.');
-      regnum = strtoul (p, &q, 10);
-      if (p == q || *q || regnum >= 32)
-	return -1;
-      if (regname[0] == 'f')
-	regnum += 32;
-      else if (regname[0] == 'v')
-	regnum += 77;
-    }
-  else if (regname[0] == 'c' && regname[1] == 'r')
-    {
-      p = regname + 2 + (regname[2] == '.');
-      if (p[0] < '0' || p[0] > '7' || p[1])
-	return -1;
-      regnum = p[0] - '0' + 68;
-    }
-  return regnum;
+  if (regname[0] == '%' && ISALPHA (regname[1]))
+    ++regname;
+
+  reg = reg_name_search (reg_names, REG_NAME_CNT, regname);
+  if (reg == NULL)
+    reg = reg_name_search (cr_names, CR_NAME_CNT, regname);
+
+  if (reg != NULL)
+    return reg->value;
+
+  return -1;
 }
diff --git a/gas/config/tc-ppc.h b/gas/config/tc-ppc.h
index ed06a29638..da3c427c4a 100644
--- a/gas/config/tc-ppc.h
+++ b/gas/config/tc-ppc.h
@@ -322,14 +322,17 @@ extern void ppc_frob_label (symbolS *);
 /* call md_pcrel_from_section, not md_pcrel_from */
 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from_section(FIX, SEC)
 
+#define LEX_PCT (LEX_BEGIN_NAME)
+
+extern int ppc_parse_name (const char *name, struct expressionS *exp);
 #define md_parse_name(name, exp, mode, c) ppc_parse_name (name, exp)
-extern int ppc_parse_name (const char *, struct expressionS *);
+
+extern void ppc_operand (expressionS *exp);
+#define md_operand ppc_operand
 
 #define md_optimize_expr(left, op, right) ppc_optimize_expr (left, op, right)
 extern int ppc_optimize_expr (expressionS *, operatorT, expressionS *);
 
-#define md_operand(x)
-
 #define md_cleanup() ppc_cleanup ()
 extern void ppc_cleanup (void);
 
-- 
2.37.0

Re: [PATCH 1/1] ppc: support register names in macros

[Dmitry Selyutin]

On Tue, Jul 12, 2022 at 4:51 PM Dmitry Selyutin <ghostmansd@gmail.com> wrote:
> @@ -7752,23 +7714,15 @@ tc_ppc_regname_to_dw2regnum (char *regname)
>      if (strcmp (regnames[i].name, regname) == 0)
>        return regnames[i].dw2regnum;
>
> -  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
> -    {
> -      p = regname + 1 + (regname[1] == '.');
> -      regnum = strtoul (p, &q, 10);
> -      if (p == q || *q || regnum >= 32)
> -       return -1;
> -      if (regname[0] == 'f')
> -       regnum += 32;
> -      else if (regname[0] == 'v')
> -       regnum += 77;
> -    }
> -  else if (regname[0] == 'c' && regname[1] == 'r')
> -    {
> -      p = regname + 2 + (regname[2] == '.');
> -      if (p[0] < '0' || p[0] > '7' || p[1])
> -       return -1;
> -      regnum = p[0] - '0' + 68;
> -    }
> -  return regnum;
> +  if (regname[0] == '%' && ISALPHA (regname[1]))
> +    ++regname;
> +
> +  reg = reg_name_search (reg_names, REG_NAME_CNT, regname);
> +  if (reg == NULL)
> +    reg = reg_name_search (cr_names, CR_NAME_CNT, regname);
> +
> +  if (reg != NULL)
> +    return reg->value;
> +
> +  return -1;
>  }

I'm by no means a CFI expert, so I'm not sure whether we should be
able to accept all registers here.
Judging from the original (overly simplified) code, we should only
consider a register with one of these flags:

    PPC_OPERAND_GPR
    PPC_OPERAND_FPR
    PPC_OPERAND_VR
    PPC_OPERAND_CR_REG

I'm inclined to add this check for reg->flags. Any objections?

-- 
Best regards,
Dmitry Selyutin

Re: [PATCH 1/1] ppc: support register names in macros

[lkcl]

On Tue, Jul 12, 2022 at 2:51 PM Dmitry Selyutin <ghostmansd@gmail.com> wrote:
> +  { "eq", 2, PPC_OPERAND_CR_BIT },

ne?

> +  { "gt", 1, PPC_OPERAND_CR_BIT },

ge?

> +  { "lt", 0, PPC_OPERAND_CR_BIT },

le?

> +  { "so", 3, PPC_OPERAND_CR_BIT },
> +  { "un", 3, PPC_OPERAND_CR_BIT }
> +};
> +#define CR_NAME_CNT    (sizeof (cr_names) / sizeof (struct pd_reg))

Re: [PATCH 1/1] ppc: support register names in macros

[Dmitry Selyutin]

On Tue, Jul 12, 2022 at 5:18 PM lkcl <luke.leighton@gmail.com> wrote:
>
> On Tue, Jul 12, 2022 at 2:51 PM Dmitry Selyutin <ghostmansd@gmail.com> wrote:
> > +  { "eq", 2, PPC_OPERAND_CR_BIT },
> ne?
> > +  { "gt", 1, PPC_OPERAND_CR_BIT },
> ge?
> > +  { "lt", 0, PPC_OPERAND_CR_BIT },
> le?

- { "cr0", 0, PPC_OPERAND_CR_REG },
- { "cr1", 1, PPC_OPERAND_CR_REG },
- { "cr2", 2, PPC_OPERAND_CR_REG },
- { "cr3", 3, PPC_OPERAND_CR_REG },
- { "cr4", 4, PPC_OPERAND_CR_REG },
- { "cr5", 5, PPC_OPERAND_CR_REG },
- { "cr6", 6, PPC_OPERAND_CR_REG },
- { "cr7", 7, PPC_OPERAND_CR_REG },
- { "eq", 2, PPC_OPERAND_CR_BIT },
- { "gt", 1, PPC_OPERAND_CR_BIT },
- { "lt", 0, PPC_OPERAND_CR_BIT },
- { "so", 3, PPC_OPERAND_CR_BIT },
- { "un", 3, PPC_OPERAND_CR_BIT }

This code simply was moved. So it either has been wrong all this time,
or it is correct. :-)

-- 
Best regards,
Dmitry Selyutin

[PATCH v2 0/1] ppc: support register names in macros

[Dmitry Selyutin]

This patch is a follow-up of discussion:

https://sourceware.org/pipermail/binutils/2022-July/121719.html

Form now on, PPC assembly becomes capable of compiling such code:

    .set VREG, %r0
    .set REG, VREG
    extsw REG, 2
    extsw %r1, 1

The custom register_name() code path, as well as checks for CRs, are
deprecated; from now on, we use md_operand() routine everywhere.

Whilst we're here, let's also reuse register lookup for CFI.

Changes since v1:
- Dropped incorrect and redundant logic regarding symbol lookup.
- Added restoring of input line pointer on failure.
- Refactored the patch so that it shows less changes.

Dmitry Selyutin (1):
  ppc: support register names in macros

 gas/config/tc-ppc.c | 232 +++++++++++++++++---------------------------
 gas/config/tc-ppc.h |   9 +-
 2 files changed, 96 insertions(+), 145 deletions(-)

-- 
2.37.0

[PATCH v2 1/1] ppc: support register names in macros

[Dmitry Selyutin]

This patch is a follow-up of discussion:

https://sourceware.org/pipermail/binutils/2022-July/121719.html

Form now on, PPC assembly becomes capable of compiling such code:

    .set VREG, %r0
    .set REG, VREG
    extsw REG, 2
    extsw %r1, 1

The custom register_name() code path, as well as checks for CRs, are
deprecated; from now on, we use md_operand() routine everywhere.

Whilst we're here, let's also reuse register lookup for CFI.
---
 gas/config/tc-ppc.c | 232 +++++++++++++++++---------------------------
 gas/config/tc-ppc.h |   9 +-
 2 files changed, 96 insertions(+), 145 deletions(-)

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 5015777d60..283cefc3a4 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -317,7 +317,7 @@ struct pd_reg
 
    The table is sorted. Suitable for searching by a binary search.  */
 
-static const struct pd_reg pre_defined_registers[] =
+static const struct pd_reg reg_names[] =
 {
   /* VSX accumulators.  */
   { "a0", 0, PPC_OPERAND_ACC },
@@ -784,95 +784,7 @@ static const struct pd_reg pre_defined_registers[] =
 
   { "xer", 1, PPC_OPERAND_SPR }
 };
-
-#define REG_NAME_CNT	(sizeof (pre_defined_registers) / sizeof (struct pd_reg))
-
-/* Given NAME, find the register number associated with that name, return
-   the integer value associated with the given name or -1 on failure.  */
-
-static const struct pd_reg *
-reg_name_search (const struct pd_reg *regs, int regcount, const char *name)
-{
-  int middle, low, high;
-  int cmp;
-
-  low = 0;
-  high = regcount - 1;
-
-  do
-    {
-      middle = (low + high) / 2;
-      cmp = strcasecmp (name, regs[middle].name);
-      if (cmp < 0)
-	high = middle - 1;
-      else if (cmp > 0)
-	low = middle + 1;
-      else
-	return &regs[middle];
-    }
-  while (low <= high);
-
-  return NULL;
-}
-
-/*
- * Summary of register_name.
- *
- * in:	Input_line_pointer points to 1st char of operand.
- *
- * out:	A expressionS.
- *      The operand may have been a register: in this case, X_op == O_register,
- *      X_add_number is set to the register number, and truth is returned.
- *	Input_line_pointer->(next non-blank) char after operand, or is in its
- *      original state.
- */
-
-static bool
-register_name (expressionS *expressionP)
-{
-  const struct pd_reg *reg;
-  char *name;
-  char *start;
-  char c;
-
-  /* Find the spelling of the operand.  */
-  start = name = input_line_pointer;
-  if (name[0] == '%' && ISALPHA (name[1]))
-    name = ++input_line_pointer;
-
-  else if (!reg_names_p || !ISALPHA (name[0]))
-    return false;
-
-  c = get_symbol_name (&name);
-  reg = reg_name_search (pre_defined_registers, REG_NAME_CNT, name);
-
-  /* Put back the delimiting char.  */
-  *input_line_pointer = c;
-
-  /* Look to see if it's in the register table.  */
-  if (reg != NULL)
-    {
-      expressionP->X_op = O_register;
-      expressionP->X_add_number = reg->value;
-      expressionP->X_md = reg->flags;
-
-      /* Make the rest nice.  */
-      expressionP->X_add_symbol = NULL;
-      expressionP->X_op_symbol = NULL;
-      return true;
-    }
-
-  /* Reset the line as if we had not done anything.  */
-  input_line_pointer = start;
-  return false;
-}
-\f
-/* This function is called for each symbol seen in an expression.  It
-   handles the special parsing which PowerPC assemblers are supposed
-   to use for condition codes.  */
-
-/* Whether to do the special parsing.  */
-static bool cr_operand;
+#define REG_NAME_CNT	(sizeof (reg_names) / sizeof (struct pd_reg))
 
 /* Names to recognize in a condition code.  This table is sorted.  */
 static const struct pd_reg cr_names[] =
@@ -891,6 +803,10 @@ static const struct pd_reg cr_names[] =
   { "so", 3, PPC_OPERAND_CR_BIT },
   { "un", 3, PPC_OPERAND_CR_BIT }
 };
+#define CR_NAME_CNT	(sizeof (cr_names) / sizeof (struct pd_reg))
+
+/* Whether to do the special parsing.  */
+static bool cr_operand;
 
 /* Parsing function.  This returns non-zero if it recognized an
    expression.  */
@@ -900,23 +816,79 @@ ppc_parse_name (const char *name, expressionS *exp)
 {
   const struct pd_reg *reg;
 
-  if (! cr_operand)
-    return 0;
-
-  if (*name == '%')
+  if (name[0] == '%' && ISALPHA (name[1]))
     ++name;
-  reg = reg_name_search (cr_names, sizeof cr_names / sizeof cr_names[0],
-			 name);
-  if (reg == NULL)
+  else if (!cr_operand && (!reg_names_p || !ISALPHA (name[0])))
     return 0;
 
-  exp->X_op = O_register;
-  exp->X_add_number = reg->value;
-  exp->X_md = reg->flags;
+  if (cr_operand)
+    reg = reg_name_search (cr_names, CR_NAME_CNT, name);
+  else
+    reg = reg_name_search (reg_names, REG_NAME_CNT, name);
+  if (reg != NULL)
+    {
+      exp->X_op = O_register;
+      exp->X_add_number = reg->value;
+      exp->X_md = reg->flags;
 
-  return 1;
+      if (! cr_operand)
+	{
+	  /* Make the rest nice.  */
+	  exp->X_add_symbol = NULL;
+	  exp->X_op_symbol = NULL;
+	}
+
+      return 1;
+    }
+
+  return 0;
+}
+
+void
+ppc_operand (expressionS *exp)
+{
+  char endc;
+  char *name;
+  char *origin = input_line_pointer;
+
+  endc = get_symbol_name (&name);
+  if (! ppc_parse_name (name, exp))
+    {
+      restore_line_pointer (endc);
+      input_line_pointer = origin;
+    }
 }
 
+/* Given NAME, find the register number associated with that name, return
+   the integer value associated with the given name or -1 on failure.  */
+
+static const struct pd_reg *
+reg_name_search (const struct pd_reg *regs, int regcount, const char *name)
+{
+  int middle, low, high;
+  int cmp;
+
+  low = 0;
+  high = regcount - 1;
+
+  do
+    {
+      middle = (low + high) / 2;
+      cmp = strcasecmp (name, regs[middle].name);
+      if (cmp < 0)
+	high = middle - 1;
+      else if (cmp > 0)
+	low = middle + 1;
+      else
+	return &regs[middle];
+    }
+  while (low <= high);
+
+  return NULL;
+}
+
+\f
+
 /* Propagate X_md and check register expressions.  This is to support
    condition codes like 4*cr5+eq.  */
 
@@ -3437,25 +3409,11 @@ md_assemble (char *str)
       /* Gather the operand.  */
       hold = input_line_pointer;
       input_line_pointer = str;
-
-      if ((reg_names_p
-	   && (((operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	       || ((operand->flags & PPC_OPERAND_CR_REG) != 0)))
-	  || !register_name (&ex))
-	{
-	  char save_lex = lex_type['%'];
-
-	  if (((operand->flags & PPC_OPERAND_CR_REG) != 0)
-	      || (operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	    {
-	      cr_operand = true;
-	      lex_type['%'] |= LEX_BEGIN_NAME;
-	    }
-	  expression (&ex);
-	  cr_operand = false;
-	  lex_type['%'] = save_lex;
-	}
-
+      memset (&ex, 0, sizeof (expressionS));
+      if (operand->flags & (PPC_OPERAND_CR_BIT | PPC_OPERAND_CR_REG))
+	cr_operand = true;
+      expression (&ex);
+      cr_operand = false;
       str = input_line_pointer;
       input_line_pointer = hold;
 
@@ -7734,10 +7692,8 @@ ppc_cfi_frame_initial_instructions (void)
 int
 tc_ppc_regname_to_dw2regnum (char *regname)
 {
-  unsigned int regnum = -1;
   unsigned int i;
-  const char *p;
-  char *q;
+  const struct pd_reg *reg;
   static struct { const char *name; int dw2regnum; } regnames[] =
     {
       { "sp", 1 }, { "r.sp", 1 }, { "rtoc", 2 }, { "r.toc", 2 },
@@ -7750,23 +7706,15 @@ tc_ppc_regname_to_dw2regnum (char *regname)
     if (strcmp (regnames[i].name, regname) == 0)
       return regnames[i].dw2regnum;
 
-  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
-    {
-      p = regname + 1 + (regname[1] == '.');
-      regnum = strtoul (p, &q, 10);
-      if (p == q || *q || regnum >= 32)
-	return -1;
-      if (regname[0] == 'f')
-	regnum += 32;
-      else if (regname[0] == 'v')
-	regnum += 77;
-    }
-  else if (regname[0] == 'c' && regname[1] == 'r')
-    {
-      p = regname + 2 + (regname[2] == '.');
-      if (p[0] < '0' || p[0] > '7' || p[1])
-	return -1;
-      regnum = p[0] - '0' + 68;
-    }
-  return regnum;
+  if (regname[0] == '%' && ISALPHA (regname[1]))
+    ++regname;
+
+  reg = reg_name_search (reg_names, REG_NAME_CNT, regname);
+  if (reg == NULL)
+    reg = reg_name_search (cr_names, CR_NAME_CNT, regname);
+
+  if (reg != NULL)
+    return reg->value;
+
+  return -1;
 }
diff --git a/gas/config/tc-ppc.h b/gas/config/tc-ppc.h
index ed06a29638..da3c427c4a 100644
--- a/gas/config/tc-ppc.h
+++ b/gas/config/tc-ppc.h
@@ -322,14 +322,17 @@ extern void ppc_frob_label (symbolS *);
 /* call md_pcrel_from_section, not md_pcrel_from */
 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from_section(FIX, SEC)
 
+#define LEX_PCT (LEX_BEGIN_NAME)
+
+extern int ppc_parse_name (const char *name, struct expressionS *exp);
 #define md_parse_name(name, exp, mode, c) ppc_parse_name (name, exp)
-extern int ppc_parse_name (const char *, struct expressionS *);
+
+extern void ppc_operand (expressionS *exp);
+#define md_operand ppc_operand
 
 #define md_optimize_expr(left, op, right) ppc_optimize_expr (left, op, right)
 extern int ppc_optimize_expr (expressionS *, operatorT, expressionS *);
 
-#define md_operand(x)
-
 #define md_cleanup() ppc_cleanup ()
 extern void ppc_cleanup (void);
 
-- 
2.37.0

[PATCH v3 0/1] ppc: support register names in macros

[Dmitry Selyutin]

This patch is a follow-up of discussion:

https://sourceware.org/pipermail/binutils/2022-July/121719.html

Form now on, PPC assembly becomes capable of compiling such code:

    .set VREG, %r0
    .set REG, VREG
    extsw REG, 2
    extsw %r1, 1

The custom register_name() code path, as well as checks for CRs, are
deprecated; from now on, we use md_operand() routine everywhere.

Whilst we're here, let's also reuse register lookup for CFI.

Changes since v2:
- Moved reg_name_search to the correct place.

Changes since v1:
- Dropped incorrect and redundant logic regarding symbol lookup.
- Added restoring of input line pointer on failure.
- Refactored the patch so that it shows less changes.

Dmitry Selyutin (1):
  ppc: support register names in macros

 gas/config/tc-ppc.c | 204 +++++++++++++++++---------------------------
 gas/config/tc-ppc.h |   9 +-
 2 files changed, 82 insertions(+), 131 deletions(-)

-- 
2.37.0

[PATCH v3 1/1] ppc: support register names in macros

[Dmitry Selyutin]

This patch is a follow-up of discussion:

https://sourceware.org/pipermail/binutils/2022-July/121719.html

Form now on, PPC assembly becomes capable of compiling such code:

    .set VREG, %r0
    .set REG, VREG
    extsw REG, 2
    extsw %r1, 1

The custom register_name() code path, as well as checks for CRs, are
deprecated; from now on, we use md_operand() routine everywhere.

Whilst we're here, let's also reuse register lookup for CFI.
---
 gas/config/tc-ppc.c | 204 +++++++++++++++++---------------------------
 gas/config/tc-ppc.h |   9 +-
 2 files changed, 82 insertions(+), 131 deletions(-)

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 5015777d60..181b1edc4d 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -317,7 +317,7 @@ struct pd_reg
 
    The table is sorted. Suitable for searching by a binary search.  */
 
-static const struct pd_reg pre_defined_registers[] =
+static const struct pd_reg reg_names[] =
 {
   /* VSX accumulators.  */
   { "a0", 0, PPC_OPERAND_ACC },
@@ -784,8 +784,26 @@ static const struct pd_reg pre_defined_registers[] =
 
   { "xer", 1, PPC_OPERAND_SPR }
 };
+#define REG_NAME_CNT	(sizeof (reg_names) / sizeof (struct pd_reg))
 
-#define REG_NAME_CNT	(sizeof (pre_defined_registers) / sizeof (struct pd_reg))
+/* Names to recognize in a condition code.  This table is sorted.  */
+static const struct pd_reg cr_names[] =
+{
+  { "cr0", 0, PPC_OPERAND_CR_REG },
+  { "cr1", 1, PPC_OPERAND_CR_REG },
+  { "cr2", 2, PPC_OPERAND_CR_REG },
+  { "cr3", 3, PPC_OPERAND_CR_REG },
+  { "cr4", 4, PPC_OPERAND_CR_REG },
+  { "cr5", 5, PPC_OPERAND_CR_REG },
+  { "cr6", 6, PPC_OPERAND_CR_REG },
+  { "cr7", 7, PPC_OPERAND_CR_REG },
+  { "eq", 2, PPC_OPERAND_CR_BIT },
+  { "gt", 1, PPC_OPERAND_CR_BIT },
+  { "lt", 0, PPC_OPERAND_CR_BIT },
+  { "so", 3, PPC_OPERAND_CR_BIT },
+  { "un", 3, PPC_OPERAND_CR_BIT }
+};
+#define CR_NAME_CNT	(sizeof (cr_names) / sizeof (struct pd_reg))
 
 /* Given NAME, find the register number associated with that name, return
    the integer value associated with the given name or -1 on failure.  */
@@ -815,83 +833,9 @@ reg_name_search (const struct pd_reg *regs, int regcount, const char *name)
   return NULL;
 }
 
-/*
- * Summary of register_name.
- *
- * in:	Input_line_pointer points to 1st char of operand.
- *
- * out:	A expressionS.
- *      The operand may have been a register: in this case, X_op == O_register,
- *      X_add_number is set to the register number, and truth is returned.
- *	Input_line_pointer->(next non-blank) char after operand, or is in its
- *      original state.
- */
-
-static bool
-register_name (expressionS *expressionP)
-{
-  const struct pd_reg *reg;
-  char *name;
-  char *start;
-  char c;
-
-  /* Find the spelling of the operand.  */
-  start = name = input_line_pointer;
-  if (name[0] == '%' && ISALPHA (name[1]))
-    name = ++input_line_pointer;
-
-  else if (!reg_names_p || !ISALPHA (name[0]))
-    return false;
-
-  c = get_symbol_name (&name);
-  reg = reg_name_search (pre_defined_registers, REG_NAME_CNT, name);
-
-  /* Put back the delimiting char.  */
-  *input_line_pointer = c;
-
-  /* Look to see if it's in the register table.  */
-  if (reg != NULL)
-    {
-      expressionP->X_op = O_register;
-      expressionP->X_add_number = reg->value;
-      expressionP->X_md = reg->flags;
-
-      /* Make the rest nice.  */
-      expressionP->X_add_symbol = NULL;
-      expressionP->X_op_symbol = NULL;
-      return true;
-    }
-
-  /* Reset the line as if we had not done anything.  */
-  input_line_pointer = start;
-  return false;
-}
-\f
-/* This function is called for each symbol seen in an expression.  It
-   handles the special parsing which PowerPC assemblers are supposed
-   to use for condition codes.  */
-
 /* Whether to do the special parsing.  */
 static bool cr_operand;
 
-/* Names to recognize in a condition code.  This table is sorted.  */
-static const struct pd_reg cr_names[] =
-{
-  { "cr0", 0, PPC_OPERAND_CR_REG },
-  { "cr1", 1, PPC_OPERAND_CR_REG },
-  { "cr2", 2, PPC_OPERAND_CR_REG },
-  { "cr3", 3, PPC_OPERAND_CR_REG },
-  { "cr4", 4, PPC_OPERAND_CR_REG },
-  { "cr5", 5, PPC_OPERAND_CR_REG },
-  { "cr6", 6, PPC_OPERAND_CR_REG },
-  { "cr7", 7, PPC_OPERAND_CR_REG },
-  { "eq", 2, PPC_OPERAND_CR_BIT },
-  { "gt", 1, PPC_OPERAND_CR_BIT },
-  { "lt", 0, PPC_OPERAND_CR_BIT },
-  { "so", 3, PPC_OPERAND_CR_BIT },
-  { "un", 3, PPC_OPERAND_CR_BIT }
-};
-
 /* Parsing function.  This returns non-zero if it recognized an
    expression.  */
 
@@ -900,23 +844,51 @@ ppc_parse_name (const char *name, expressionS *exp)
 {
   const struct pd_reg *reg;
 
-  if (! cr_operand)
-    return 0;
-
-  if (*name == '%')
+  if (name[0] == '%' && ISALPHA (name[1]))
     ++name;
-  reg = reg_name_search (cr_names, sizeof cr_names / sizeof cr_names[0],
-			 name);
-  if (reg == NULL)
+  else if (!cr_operand && (!reg_names_p || !ISALPHA (name[0])))
     return 0;
 
-  exp->X_op = O_register;
-  exp->X_add_number = reg->value;
-  exp->X_md = reg->flags;
+  if (cr_operand)
+    reg = reg_name_search (cr_names, CR_NAME_CNT, name);
+  else
+    reg = reg_name_search (reg_names, REG_NAME_CNT, name);
+  if (reg != NULL)
+    {
+      exp->X_op = O_register;
+      exp->X_add_number = reg->value;
+      exp->X_md = reg->flags;
+
+      if (! cr_operand)
+	{
+	  /* Make the rest nice.  */
+	  exp->X_add_symbol = NULL;
+	  exp->X_op_symbol = NULL;
+	}
 
-  return 1;
+      return 1;
+    }
+
+  return 0;
 }
 
+void
+ppc_operand (expressionS *exp)
+{
+  char endc;
+  char *name;
+  char *origin = input_line_pointer;
+
+  endc = get_symbol_name (&name);
+  if (! ppc_parse_name (name, exp))
+    {
+      restore_line_pointer (endc);
+      input_line_pointer = origin;
+    }
+}
+
+\f
+
 /* Propagate X_md and check register expressions.  This is to support
    condition codes like 4*cr5+eq.  */
 
@@ -3437,25 +3409,11 @@ md_assemble (char *str)
       /* Gather the operand.  */
       hold = input_line_pointer;
       input_line_pointer = str;
-
-      if ((reg_names_p
-	   && (((operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	       || ((operand->flags & PPC_OPERAND_CR_REG) != 0)))
-	  || !register_name (&ex))
-	{
-	  char save_lex = lex_type['%'];
-
-	  if (((operand->flags & PPC_OPERAND_CR_REG) != 0)
-	      || (operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	    {
-	      cr_operand = true;
-	      lex_type['%'] |= LEX_BEGIN_NAME;
-	    }
-	  expression (&ex);
-	  cr_operand = false;
-	  lex_type['%'] = save_lex;
-	}
-
+      memset (&ex, 0, sizeof (expressionS));
+      if (operand->flags & (PPC_OPERAND_CR_BIT | PPC_OPERAND_CR_REG))
+	cr_operand = true;
+      expression (&ex);
+      cr_operand = false;
       str = input_line_pointer;
       input_line_pointer = hold;
 
@@ -7734,10 +7692,8 @@ ppc_cfi_frame_initial_instructions (void)
 int
 tc_ppc_regname_to_dw2regnum (char *regname)
 {
-  unsigned int regnum = -1;
   unsigned int i;
-  const char *p;
-  char *q;
+  const struct pd_reg *reg;
   static struct { const char *name; int dw2regnum; } regnames[] =
     {
       { "sp", 1 }, { "r.sp", 1 }, { "rtoc", 2 }, { "r.toc", 2 },
@@ -7750,23 +7706,15 @@ tc_ppc_regname_to_dw2regnum (char *regname)
     if (strcmp (regnames[i].name, regname) == 0)
       return regnames[i].dw2regnum;
 
-  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
-    {
-      p = regname + 1 + (regname[1] == '.');
-      regnum = strtoul (p, &q, 10);
-      if (p == q || *q || regnum >= 32)
-	return -1;
-      if (regname[0] == 'f')
-	regnum += 32;
-      else if (regname[0] == 'v')
-	regnum += 77;
-    }
-  else if (regname[0] == 'c' && regname[1] == 'r')
-    {
-      p = regname + 2 + (regname[2] == '.');
-      if (p[0] < '0' || p[0] > '7' || p[1])
-	return -1;
-      regnum = p[0] - '0' + 68;
-    }
-  return regnum;
+  if (regname[0] == '%' && ISALPHA (regname[1]))
+    ++regname;
+
+  reg = reg_name_search (reg_names, REG_NAME_CNT, regname);
+  if (reg == NULL)
+    reg = reg_name_search (cr_names, CR_NAME_CNT, regname);
+
+  if (reg != NULL)
+    return reg->value;
+
+  return -1;
 }
diff --git a/gas/config/tc-ppc.h b/gas/config/tc-ppc.h
index ed06a29638..da3c427c4a 100644
--- a/gas/config/tc-ppc.h
+++ b/gas/config/tc-ppc.h
@@ -322,14 +322,17 @@ extern void ppc_frob_label (symbolS *);
 /* call md_pcrel_from_section, not md_pcrel_from */
 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from_section(FIX, SEC)
 
+#define LEX_PCT (LEX_BEGIN_NAME)
+
+extern int ppc_parse_name (const char *name, struct expressionS *exp);
 #define md_parse_name(name, exp, mode, c) ppc_parse_name (name, exp)
-extern int ppc_parse_name (const char *, struct expressionS *);
+
+extern void ppc_operand (expressionS *exp);
+#define md_operand ppc_operand
 
 #define md_optimize_expr(left, op, right) ppc_optimize_expr (left, op, right)
 extern int ppc_optimize_expr (expressionS *, operatorT, expressionS *);
 
-#define md_operand(x)
-
 #define md_cleanup() ppc_cleanup ()
 extern void ppc_cleanup (void);
 
-- 
2.37.0

Re: [PATCH v3 1/1] ppc: support register names in macros

[Alan Modra]

On Wed, Jul 13, 2022 at 12:29:59AM +0300, Dmitry Selyutin wrote:
> +#define LEX_PCT (LEX_BEGIN_NAME)
> +

This would allow '%' to start symbols and labels, and I think that is
a bad idea.  I've also been working on a patch, wasting a lot of time
trying to change expr.c:operand in a way that allows the powerpc
register type checks in X_md to work.  ie.

 .set a,%f4
 .set b,%cr3
 .set c,%r31
 addi a,b,c

ought to warn about invalid registers.  In the end I gave up and just
moved some code from operand() to ppc_parse_name().  I'll commit the
following tomorrow assuming overnight checks pass.

	* gas/config/tc-ppc.c (REG_NAME_CNT): Delete, replace uses with
	ARRAY_SIZE.
	(register_name): Rename to..
	(md_operand): ..this.  Only handle %reg.
	(cr_names): Rename to..
	(cr_cond): ..this.  Just keep conditions.
	(ppc_parse_name): Add mode param.  Search both cr_cond and
	pre_defined_registers.  Handle absolute and register symbol
	values here rather than in expr.
	(md_assemble): Don't special case register name matching in
	operands, except to set cr_operand as appropriate.
	* gas/config/tc-ppc.h (md_operand): Don't define.
	(md_parse_name, ppc_parse_name): Update.
	* read.c (pseudo_set): Copy over entire O_register value.
	* testsuite/gas/ppc/regsyms.d.
	* testsuite/gas/ppc/regsyms.s: New test.
	* testsuite/gas/ppc/ppc.exp: Run it.

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 5015777d600..05d8ee19be7 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -785,8 +785,6 @@ static const struct pd_reg pre_defined_registers[] =
   { "xer", 1, PPC_OPERAND_SPR }
 };
 
-#define REG_NAME_CNT	(sizeof (pre_defined_registers) / sizeof (struct pd_reg))
-
 /* Given NAME, find the register number associated with that name, return
    the integer value associated with the given name or -1 on failure.  */
 
@@ -815,76 +813,43 @@ reg_name_search (const struct pd_reg *regs, int regcount, const char *name)
   return NULL;
 }
 
-/*
- * Summary of register_name.
- *
- * in:	Input_line_pointer points to 1st char of operand.
- *
- * out:	A expressionS.
- *      The operand may have been a register: in this case, X_op == O_register,
- *      X_add_number is set to the register number, and truth is returned.
- *	Input_line_pointer->(next non-blank) char after operand, or is in its
- *      original state.
- */
+/* Called for a non-symbol, non-number operand.  Handles %reg.  */
 
-static bool
-register_name (expressionS *expressionP)
+void
+md_operand (expressionS *expressionP)
 {
   const struct pd_reg *reg;
   char *name;
   char *start;
   char c;
 
-  /* Find the spelling of the operand.  */
-  start = name = input_line_pointer;
-  if (name[0] == '%' && ISALPHA (name[1]))
-    name = ++input_line_pointer;
+  if (input_line_pointer[0] != '%' || !ISALPHA (input_line_pointer[1]))
+    return;
 
-  else if (!reg_names_p || !ISALPHA (name[0]))
-    return false;
+  start = input_line_pointer;
+  ++input_line_pointer;
 
   c = get_symbol_name (&name);
-  reg = reg_name_search (pre_defined_registers, REG_NAME_CNT, name);
-
-  /* Put back the delimiting char.  */
+  reg = reg_name_search (pre_defined_registers,
+			 ARRAY_SIZE (pre_defined_registers), name);
   *input_line_pointer = c;
 
-  /* Look to see if it's in the register table.  */
   if (reg != NULL)
     {
       expressionP->X_op = O_register;
       expressionP->X_add_number = reg->value;
       expressionP->X_md = reg->flags;
-
-      /* Make the rest nice.  */
-      expressionP->X_add_symbol = NULL;
-      expressionP->X_op_symbol = NULL;
-      return true;
     }
-
-  /* Reset the line as if we had not done anything.  */
-  input_line_pointer = start;
-  return false;
+  else
+    input_line_pointer = start;
 }
-\f
-/* This function is called for each symbol seen in an expression.  It
-   handles the special parsing which PowerPC assemblers are supposed
-   to use for condition codes.  */
 
 /* Whether to do the special parsing.  */
 static bool cr_operand;
 
-/* Names to recognize in a condition code.  This table is sorted.  */
-static const struct pd_reg cr_names[] =
+/* Extra names to recognise in a condition code.  This table is sorted.  */
+static const struct pd_reg cr_cond[] =
 {
-  { "cr0", 0, PPC_OPERAND_CR_REG },
-  { "cr1", 1, PPC_OPERAND_CR_REG },
-  { "cr2", 2, PPC_OPERAND_CR_REG },
-  { "cr3", 3, PPC_OPERAND_CR_REG },
-  { "cr4", 4, PPC_OPERAND_CR_REG },
-  { "cr5", 5, PPC_OPERAND_CR_REG },
-  { "cr6", 6, PPC_OPERAND_CR_REG },
-  { "cr7", 7, PPC_OPERAND_CR_REG },
   { "eq", 2, PPC_OPERAND_CR_BIT },
   { "gt", 1, PPC_OPERAND_CR_BIT },
   { "lt", 0, PPC_OPERAND_CR_BIT },
@@ -892,29 +857,60 @@ static const struct pd_reg cr_names[] =
   { "un", 3, PPC_OPERAND_CR_BIT }
 };
 
-/* Parsing function.  This returns non-zero if it recognized an
-   expression.  */
+/* This function is called for each symbol seen in an expression.  It
+   handles the special parsing which PowerPC assemblers are supposed
+   to use for condition codes, and recognises other registers when
+   -mregnames.  */
 
 int
-ppc_parse_name (const char *name, expressionS *exp)
+ppc_parse_name (const char *name, expressionS *exp, enum expr_mode mode)
 {
-  const struct pd_reg *reg;
+  const struct pd_reg *reg = NULL;
 
-  if (! cr_operand)
-    return 0;
+  if (cr_operand)
+    reg = reg_name_search (cr_cond, ARRAY_SIZE (cr_cond), name);
+  if (reg == NULL && (cr_operand || reg_names_p))
+    reg = reg_name_search (pre_defined_registers,
+			   ARRAY_SIZE (pre_defined_registers), name);
+  if (reg != NULL)
+    {
+      exp->X_op = O_register;
+      exp->X_add_number = reg->value;
+      exp->X_md = reg->flags;
+      return true;
+    }
 
-  if (*name == '%')
-    ++name;
-  reg = reg_name_search (cr_names, sizeof cr_names / sizeof cr_names[0],
-			 name);
-  if (reg == NULL)
-    return 0;
+  /* The following replaces code in expr.c operand() after the
+     md_parse_name call.  There is too much difference between targets
+     in the way X_md is used to move this code into expr.c.  If you
+     do, you'll get failures on x86 due to uninitialised X_md fields,
+     failures on alpha and other targets due to creating register
+     symbols as O_constant rather than O_register, and failures on arc
+     and others due to expecting expr() to leave X_md alone.  */
+  symbolS *sym = symbol_find_or_make (name);
 
-  exp->X_op = O_register;
-  exp->X_add_number = reg->value;
-  exp->X_md = reg->flags;
+  /* If we have an absolute symbol or a reg, then we know its value
+     now.  Copy the symbol value expression to propagate X_md.  */
+  bool done = false;
+  if (mode != expr_defer
+      && !S_FORCE_RELOC (sym, 0))
+    {
+      segT segment = S_GET_SEGMENT (sym);
+      if (segment == absolute_section || segment == reg_section)
+	{
+	  resolve_symbol_value (sym);
+	  *exp = *symbol_get_value_expression (sym);
+	  done = true;
+	}
+    }
+  if (!done)
+    {
+      exp->X_op = O_symbol;
+      exp->X_add_symbol = sym;
+      exp->X_add_number = 0;
+    }
 
-  return 1;
+  return true;
 }
 
 /* Propagate X_md and check register expressions.  This is to support
@@ -3437,25 +3433,10 @@ md_assemble (char *str)
       /* Gather the operand.  */
       hold = input_line_pointer;
       input_line_pointer = str;
-
-      if ((reg_names_p
-	   && (((operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	       || ((operand->flags & PPC_OPERAND_CR_REG) != 0)))
-	  || !register_name (&ex))
-	{
-	  char save_lex = lex_type['%'];
-
-	  if (((operand->flags & PPC_OPERAND_CR_REG) != 0)
-	      || (operand->flags & PPC_OPERAND_CR_BIT) != 0)
-	    {
-	      cr_operand = true;
-	      lex_type['%'] |= LEX_BEGIN_NAME;
-	    }
-	  expression (&ex);
-	  cr_operand = false;
-	  lex_type['%'] = save_lex;
-	}
-
+      cr_operand = ((operand->flags & PPC_OPERAND_CR_BIT) != 0
+		    || (operand->flags & PPC_OPERAND_CR_REG) != 0);
+      expression (&ex);
+      cr_operand = false;
       str = input_line_pointer;
       input_line_pointer = hold;
 
diff --git a/gas/config/tc-ppc.h b/gas/config/tc-ppc.h
index ed06a296382..480c952be45 100644
--- a/gas/config/tc-ppc.h
+++ b/gas/config/tc-ppc.h
@@ -322,14 +322,12 @@ extern void ppc_frob_label (symbolS *);
 /* call md_pcrel_from_section, not md_pcrel_from */
 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from_section(FIX, SEC)
 
-#define md_parse_name(name, exp, mode, c) ppc_parse_name (name, exp)
-extern int ppc_parse_name (const char *, struct expressionS *);
+#define md_parse_name(name, exp, mode, c) ppc_parse_name (name, exp, mode)
+extern int ppc_parse_name (const char *, struct expressionS *, enum expr_mode);
 
 #define md_optimize_expr(left, op, right) ppc_optimize_expr (left, op, right)
 extern int ppc_optimize_expr (expressionS *, operatorT, expressionS *);
 
-#define md_operand(x)
-
 #define md_cleanup() ppc_cleanup ()
 extern void ppc_cleanup (void);
 
diff --git a/gas/read.c b/gas/read.c
index 6f3a51df761..559fd05a8db 100644
--- a/gas/read.c
+++ b/gas/read.c
@@ -3934,10 +3934,9 @@ pseudo_set (symbolS *symbolP)
 	  return;
 	}
 #endif
+      symbol_set_value_expression (symbolP, &exp);
       S_SET_SEGMENT (symbolP, reg_section);
-      S_SET_VALUE (symbolP, (valueT) exp.X_add_number);
       set_zero_frag (symbolP);
-      symbol_get_value_expression (symbolP)->X_op = O_register;
       break;
 
     case O_symbol:
diff --git a/gas/testsuite/gas/ppc/ppc.exp b/gas/testsuite/gas/ppc/ppc.exp
index a2e23a2c6af..9844ce7e4a1 100644
--- a/gas/testsuite/gas/ppc/ppc.exp
+++ b/gas/testsuite/gas/ppc/ppc.exp
@@ -36,6 +36,7 @@ run_dump_test "bcy"
 run_dump_test "bcaterr"
 run_dump_test "bcat"
 run_dump_test "regnames"
+run_dump_test "regsyms"
 run_dump_test "misalign"
 run_dump_test "misalign2"
 run_dump_test "machine"
diff --git a/gas/testsuite/gas/ppc/regsyms.d b/gas/testsuite/gas/ppc/regsyms.d
new file mode 100644
index 00000000000..7586b0df4ca
--- /dev/null
+++ b/gas/testsuite/gas/ppc/regsyms.d
@@ -0,0 +1,10 @@
+#as: -mregnames
+#objdump: -d
+
+.*:     file format .*
+
+Disassembly of section \.text:
+
+0+ <.text>:
+   0:	(7c 43 13 78|78 13 43 7c) 	mr      r3,r2
+   4:	(7f c3 f3 78|78 f3 c3 7f) 	mr      r3,r30
diff --git a/gas/testsuite/gas/ppc/regsyms.s b/gas/testsuite/gas/ppc/regsyms.s
new file mode 100644
index 00000000000..6dc3ddc070b
--- /dev/null
+++ b/gas/testsuite/gas/ppc/regsyms.s
@@ -0,0 +1,4 @@
+ tocp = %r2
+ mr %r3,tocp
+ x = r30
+ mr 3,x


-- 
Alan Modra
Australia Development Lab, IBM

Re: PowerPC: implement md_operand to parse register names

[Alan Modra]

I meant to make this change before committing, to let compilers know
the code on the false branch of md_parse_name is dead.

	* config/tc-ppc.c (ppc_parse_name): Return void.
	* config/tc-ppc.h (md_parse_name): Always true.
	(ppc_parse_name): Update prototype.

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 05d8ee19be7..452fab1cbfc 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -862,7 +862,7 @@ static const struct pd_reg cr_cond[] =
    to use for condition codes, and recognises other registers when
    -mregnames.  */
 
-int
+void
 ppc_parse_name (const char *name, expressionS *exp, enum expr_mode mode)
 {
   const struct pd_reg *reg = NULL;
@@ -877,7 +877,7 @@ ppc_parse_name (const char *name, expressionS *exp, enum expr_mode mode)
       exp->X_op = O_register;
       exp->X_add_number = reg->value;
       exp->X_md = reg->flags;
-      return true;
+      return;
     }
 
   /* The following replaces code in expr.c operand() after the
@@ -909,8 +909,6 @@ ppc_parse_name (const char *name, expressionS *exp, enum expr_mode mode)
       exp->X_add_symbol = sym;
       exp->X_add_number = 0;
     }
-
-  return true;
 }
 
 /* Propagate X_md and check register expressions.  This is to support
diff --git a/gas/config/tc-ppc.h b/gas/config/tc-ppc.h
index 480c952be45..de9522d4bf6 100644
--- a/gas/config/tc-ppc.h
+++ b/gas/config/tc-ppc.h
@@ -322,8 +322,9 @@ extern void ppc_frob_label (symbolS *);
 /* call md_pcrel_from_section, not md_pcrel_from */
 #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from_section(FIX, SEC)
 
-#define md_parse_name(name, exp, mode, c) ppc_parse_name (name, exp, mode)
-extern int ppc_parse_name (const char *, struct expressionS *, enum expr_mode);
+#define md_parse_name(name, exp, mode, c) \
+  (ppc_parse_name (name, exp, mode), true)
+extern void ppc_parse_name (const char *, struct expressionS *, enum expr_mode);
 
 #define md_optimize_expr(left, op, right) ppc_optimize_expr (left, op, right)
 extern int ppc_optimize_expr (expressionS *, operatorT, expressionS *);

-- 
Alan Modra
Australia Development Lab, IBM

Re: [PATCH v3 1/1] ppc: support register names in macros

[Dmitry Selyutin]

On Wed, Jul 13, 2022 at 6:34 PM Alan Modra <amodra@gmail.com> wrote:
> diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
> index 5015777d600..05d8ee19be7 100644
> --- a/gas/config/tc-ppc.c
> +++ b/gas/config/tc-ppc.c

Whilst we're here, I suggest taking this opportunity to re-use some
bits for CFI, which invented a custom register parsing. :-)

--
Best regards,
Dmitry Selyutin

[PATCH] ppc: use reg_name_search for CFI register lookup

[Dmitry Selyutin]

---
 gas/config/tc-ppc.c | 37 +++++++++++++++----------------------
 1 file changed, 15 insertions(+), 22 deletions(-)

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 05d8ee19be..765eb3fa2f 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -7715,10 +7715,8 @@ ppc_cfi_frame_initial_instructions (void)
 int
 tc_ppc_regname_to_dw2regnum (char *regname)
 {
-  unsigned int regnum = -1;
   unsigned int i;
-  const char *p;
-  char *q;
+  const struct pd_reg *reg;
   static struct { const char *name; int dw2regnum; } regnames[] =
     {
       { "sp", 1 }, { "r.sp", 1 }, { "rtoc", 2 }, { "r.toc", 2 },
@@ -7731,23 +7729,18 @@ tc_ppc_regname_to_dw2regnum (char *regname)
     if (strcmp (regnames[i].name, regname) == 0)
       return regnames[i].dw2regnum;
 
-  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
-    {
-      p = regname + 1 + (regname[1] == '.');
-      regnum = strtoul (p, &q, 10);
-      if (p == q || *q || regnum >= 32)
-	return -1;
-      if (regname[0] == 'f')
-	regnum += 32;
-      else if (regname[0] == 'v')
-	regnum += 77;
-    }
-  else if (regname[0] == 'c' && regname[1] == 'r')
-    {
-      p = regname + 2 + (regname[2] == '.');
-      if (p[0] < '0' || p[0] > '7' || p[1])
-	return -1;
-      regnum = p[0] - '0' + 68;
-    }
-  return regnum;
+  if (regname[0] == '%' && ISALPHA (regname[1]))
+    ++regname;
+
+  reg = reg_name_search (pre_defined_registers,
+    ARRAY_SIZE (pre_defined_registers), regname);
+
+  if ((reg != NULL) &&
+      (((reg->flags & PPC_OPERAND_GPR) == PPC_OPERAND_GPR) ||
+       ((reg->flags & PPC_OPERAND_FPR) == PPC_OPERAND_FPR) ||
+       ((reg->flags & PPC_OPERAND_VR) == PPC_OPERAND_VR) ||
+       ((reg->flags & PPC_OPERAND_CR_REG) == PPC_OPERAND_CR_REG)))
+    return reg->value;
+
+  return -1;
 }
-- 
2.37.0

Re: [PATCH] ppc: use reg_name_search for CFI register lookup

[Alan Modra]

No, that's completely broken.  The numbers we want to return from
tc_ppc_regname_to_dw2regnum are not those in reg->value.

-- 
Alan Modra
Australia Development Lab, IBM

[PATCH v2] ppc: use reg_name_search for CFI register lookup

[Dmitry Selyutin]

---
 gas/config/tc-ppc.c | 41 +++++++++++++++++++----------------------
 1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 452fab1cbf..c6715535c7 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -7713,10 +7713,8 @@ ppc_cfi_frame_initial_instructions (void)
 int
 tc_ppc_regname_to_dw2regnum (char *regname)
 {
-  unsigned int regnum = -1;
   unsigned int i;
-  const char *p;
-  char *q;
+  const struct pd_reg *reg;
   static struct { const char *name; int dw2regnum; } regnames[] =
     {
       { "sp", 1 }, { "r.sp", 1 }, { "rtoc", 2 }, { "r.toc", 2 },
@@ -7729,23 +7727,22 @@ tc_ppc_regname_to_dw2regnum (char *regname)
     if (strcmp (regnames[i].name, regname) == 0)
       return regnames[i].dw2regnum;
 
-  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
-    {
-      p = regname + 1 + (regname[1] == '.');
-      regnum = strtoul (p, &q, 10);
-      if (p == q || *q || regnum >= 32)
-	return -1;
-      if (regname[0] == 'f')
-	regnum += 32;
-      else if (regname[0] == 'v')
-	regnum += 77;
-    }
-  else if (regname[0] == 'c' && regname[1] == 'r')
-    {
-      p = regname + 2 + (regname[2] == '.');
-      if (p[0] < '0' || p[0] > '7' || p[1])
-	return -1;
-      regnum = p[0] - '0' + 68;
-    }
-  return regnum;
+  if (regname[0] == '%' && ISALPHA (regname[1]))
+    ++regname;
+
+  reg = reg_name_search (pre_defined_registers,
+    ARRAY_SIZE (pre_defined_registers), regname);
+  if (reg == NULL)
+    return -1;
+
+  if ((reg->flags & PPC_OPERAND_GPR) == PPC_OPERAND_GPR)
+    return reg->value;
+  else if ((reg->flags & PPC_OPERAND_FPR) == PPC_OPERAND_FPR)
+    return (reg->value + 32);
+  else if ((reg->flags & PPC_OPERAND_VR) == PPC_OPERAND_VR)
+    return (reg->value + 77);
+  else if ((reg->flags & PPC_OPERAND_CR_REG) == PPC_OPERAND_CR_REG)
+    return (reg->value + 68);
+  else
+    return -1;
 }
-- 
2.37.0

Re: [PATCH] ppc: use reg_name_search for CFI register lookup

[Dmitry Selyutin]

On Thu, Jul 14, 2022 at 10:25 AM Alan Modra <amodra@gmail.com> wrote:
>
> No, that's completely broken.  The numbers we want to return from
> tc_ppc_regname_to_dw2regnum are not those in reg->value.

Yeah sorry I totally missed that the results are tuned. Updated.

-- 
Best regards,
Dmitry Selyutin

Re: [PATCH] ppc: use reg_name_search for CFI register lookup

[Dmitry Selyutin]

On Thu, Jul 14, 2022 at 11:23 AM Dmitry Selyutin <ghostmansd@gmail.com> wrote:
> Yeah sorry I totally missed that the results are tuned. Updated.

Hm. Perhaps we need some test covering it? Say some as/objdump
combination. It's a bit strange that cfi-ppc-1.d hasn't caught it.

-- 
Best regards,
Dmitry Selyutin

Re: [PATCH v2] ppc: use reg_name_search for CFI register lookup

[Alan Modra]

On Thu, Jul 14, 2022 at 11:21:12AM +0300, Dmitry Selyutin wrote:
> ---
>  gas/config/tc-ppc.c | 41 +++++++++++++++++++----------------------
>  1 file changed, 19 insertions(+), 22 deletions(-)
> 
> diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
> index 452fab1cbf..c6715535c7 100644
> --- a/gas/config/tc-ppc.c
> +++ b/gas/config/tc-ppc.c
> @@ -7713,10 +7713,8 @@ ppc_cfi_frame_initial_instructions (void)
>  int
>  tc_ppc_regname_to_dw2regnum (char *regname)
>  {
> -  unsigned int regnum = -1;
>    unsigned int i;
> -  const char *p;
> -  char *q;
> +  const struct pd_reg *reg;
>    static struct { const char *name; int dw2regnum; } regnames[] =
>      {
>        { "sp", 1 }, { "r.sp", 1 }, { "rtoc", 2 }, { "r.toc", 2 },
> @@ -7729,23 +7727,22 @@ tc_ppc_regname_to_dw2regnum (char *regname)
>      if (strcmp (regnames[i].name, regname) == 0)
>        return regnames[i].dw2regnum;
>  
> -  if (regname[0] == 'r' || regname[0] == 'f' || regname[0] == 'v')
> -    {
> -      p = regname + 1 + (regname[1] == '.');
> -      regnum = strtoul (p, &q, 10);
> -      if (p == q || *q || regnum >= 32)
> -	return -1;
> -      if (regname[0] == 'f')
> -	regnum += 32;
> -      else if (regname[0] == 'v')
> -	regnum += 77;
> -    }
> -  else if (regname[0] == 'c' && regname[1] == 'r')
> -    {
> -      p = regname + 2 + (regname[2] == '.');
> -      if (p[0] < '0' || p[0] > '7' || p[1])
> -	return -1;
> -      regnum = p[0] - '0' + 68;
> -    }
> -  return regnum;
> +  if (regname[0] == '%' && ISALPHA (regname[1]))
> +    ++regname;

No need for the above, any '%' is trimmed off and regname is
guaranteed to be a name by the caller of tc_regname_to_dw2regnum.

> +  reg = reg_name_search (pre_defined_registers,
> +    ARRAY_SIZE (pre_defined_registers), regname);

Doing the reg_name_search before the odd ones in regnames[] would be
better, wouldn't it?  And you can delete the first row of regnames[].
OK with those changes.

> +  if (reg == NULL)
> +    return -1;
> +
> +  if ((reg->flags & PPC_OPERAND_GPR) == PPC_OPERAND_GPR)
> +    return reg->value;
> +  else if ((reg->flags & PPC_OPERAND_FPR) == PPC_OPERAND_FPR)
> +    return (reg->value + 32);
> +  else if ((reg->flags & PPC_OPERAND_VR) == PPC_OPERAND_VR)
> +    return (reg->value + 77);
> +  else if ((reg->flags & PPC_OPERAND_CR_REG) == PPC_OPERAND_CR_REG)
> +    return (reg->value + 68);
> +  else
> +    return -1;
>  }
> -- 
> 2.37.0

-- 
Alan Modra
Australia Development Lab, IBM

Re: [PATCH] ppc: use reg_name_search for CFI register lookup

[Alan Modra]

On Thu, Jul 14, 2022 at 11:25:43AM +0300, Dmitry Selyutin wrote:
> On Thu, Jul 14, 2022 at 11:23 AM Dmitry Selyutin <ghostmansd@gmail.com> wrote:
> > Yeah sorry I totally missed that the results are tuned. Updated.
> 
> Hm. Perhaps we need some test covering it? Say some as/objdump
> combination. It's a bit strange that cfi-ppc-1.d hasn't caught it.

Yes, the test isn't that good, only checking cfi for gprs.

-- 
Alan Modra
Australia Development Lab, IBM