[arm] Add support for aliases of CPU names

Message ID 7512aca1-1fa6-6fb3-2636-03675bf77177@arm.com
State New
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  • [arm] Add support for aliases of CPU names
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Commit Message

Richard Earnshaw (lists) Nov. 8, 2018, 5:49 p.m.
This patch adds support for defining an alias for a CPU name that can
then be used in conjunction with the -mcpu option in the same way that
the primary name can be used.  Aliases do not lead to a short-cut of
the feature options; they are literally an alternative name for the
core CPU.

The new entry in arm-cpus.in allows a cpu definition to contain an
alias statement, for example

begin cpu strongarm
 alias strongarm110 !strongarm1100 !strongarm1110
 ...
end cpu strongarm

each entry in the list represents another alias for the CPU.  If the
alias name starts with an exclamation mark, then it will match as for
any other alias (sans the ! itself), but it will not be listed in any
of the CPU hinting options (the intent is to make the alias
essentially undocumented).  In the above example, hints would be
provided for strongarm and strongarm110, but not for strongarm1100 or
strongarm1110.

The advantage of using aliases in this way is that it allows us to
reduce the number of duplicate table entries and identifier tags used
inside the compiler itself.

	* config/arm/parsecpu.awk (/alias/): New parsing rule.
	(/begin cpu/): Check that the cpu name hasn't been previously defined.
	(gen_comm_data): Print out CPU alias tables.
	(check_cpu): Match aliases when checking the CPU name.
	* config/arm/arm-protos.h (cpu_alias): New structure.
	(cpu_option): Add entry for aliases.
	* config/arm/arm-cpus.in (strongarm): Add aliases for strongarm110
	strongarm1100 and strongarm1110.
	(strongarm110, strongarm1100, strongarm1110): Delete CPU entries.
	(config/arm/arm-generic.md): Remove redundant references to
	strongarm110, strongarm1100 and strongarm1110.
	* common/config/arm/arm-common.c (arm_print_hint_for_cpu_option):
	Scan aliases for additional hints.
	(arm_parse_cpu_option_name): Also match a cpu name against the list
	of aliases.
	* config/arm/arm-tables.opt: Regenerated.
	* config/arm/arm-tune.md: Regenerated.

Committed to trunk.

R.

Patch

diff --git a/gcc/common/config/arm/arm-common.c b/gcc/common/config/arm/arm-common.c
index 76c357b4258..32cf36e94f6 100644
--- a/gcc/common/config/arm/arm-common.c
+++ b/gcc/common/config/arm/arm-common.c
@@ -309,7 +309,16 @@  arm_print_hint_for_cpu_option (const char *target,
 {
   auto_vec<const char*> candidates;
   for (; list->common.name != NULL; list++)
-    candidates.safe_push (list->common.name);
+    {
+      candidates.safe_push (list->common.name);
+      if (list->aliases)
+	{
+	  for (const cpu_alias *alias = list->aliases; alias->name != NULL;
+	       alias++)
+	    if (alias->visible)
+	      candidates.safe_push (alias->name);
+	}
+    }
 
 #ifdef HAVE_LOCAL_CPU_DETECT
   /* Add also "native" as possible value.  */
@@ -345,6 +354,16 @@  arm_parse_cpu_option_name (const cpu_option *list, const char *optname,
       if (strncmp (entry->common.name, target, len) == 0
 	  && entry->common.name[len] == '\0')
 	return entry;
+
+      /* Match against any legal alias for this CPU candidate.  */
+      if (entry->aliases)
+	{
+	  for (const cpu_alias *alias = entry->aliases; alias->name != NULL;
+	       alias++)
+	    if (strncmp (alias->name, target, len) == 0
+		&& alias->name[len] == '\0')
+	      return entry;
+	}
     }
 
   if (complain)
diff --git a/gcc/config/arm/arm-cpus.in b/gcc/config/arm/arm-cpus.in
index d82e95a2266..61b17b57af7 100644
--- a/gcc/config/arm/arm-cpus.in
+++ b/gcc/config/arm/arm-cpus.in
@@ -617,6 +617,7 @@  end arch iwmmxt2
 # format:
 # begin cpu <name>
 #   [cname <c-compatible-name>]
+#   [alias <name>+]
 #   [tune for <cpu-name>]
 #   [tune flags <list>]
 #   architecture <name>
@@ -630,6 +631,9 @@  end arch iwmmxt2
 #
 # If omitted, cname is formed from transforming the cpuname to convert
 # non-valid punctuation characters to '_'.
+# Any number of alias names may be specified for a CPU.  If the name starts
+# with a '!' then it will be recognized as a valid name, but will not
+# be printed in any help text listing permitted CPUs.
 # If specified, tune for specifies a CPU target to use for tuning this core.
 # isa flags are appended to those defined by the architecture.
 # Each add option must have a distinct feature set and each remove
@@ -658,29 +662,12 @@  begin cpu arm810
 end cpu arm810
 
 begin cpu strongarm
+ alias strongarm110 !strongarm1100 !strongarm1110
  tune flags LDSCHED STRONG
  architecture armv4
  costs strongarm
 end cpu strongarm
 
-begin cpu strongarm110
- tune flags LDSCHED STRONG
- architecture armv4
- costs strongarm
-end cpu strongarm110
-
-begin cpu strongarm1100
- tune flags LDSCHED STRONG
- architecture armv4
- costs strongarm
-end cpu strongarm1100
-
-begin cpu strongarm1110
- tune flags LDSCHED STRONG
- architecture armv4
- costs strongarm
-end cpu strongarm1110
-
 begin cpu fa526
  tune flags LDSCHED
  architecture armv4
diff --git a/gcc/config/arm/arm-generic.md b/gcc/config/arm/arm-generic.md
index 81200fa499a..da97303c758 100644
--- a/gcc/config/arm/arm-generic.md
+++ b/gcc/config/arm/arm-generic.md
@@ -122,8 +122,7 @@  (define_insn_reservation "mult" 16
 (define_insn_reservation "mult_ldsched_strongarm" 3
   (and (eq_attr "generic_sched" "yes")
        (and (eq_attr "ldsched" "yes") 
-	    (and (eq_attr "tune"
-		  "strongarm,strongarm110,strongarm1100,strongarm1110")
+	    (and (eq_attr "tune" "strongarm")
 		 (ior (eq_attr "mul32" "yes")
 		      (eq_attr "mul64" "yes")))))
   "core*2")
@@ -131,8 +130,7 @@  (define_insn_reservation "mult_ldsched_strongarm" 3
 (define_insn_reservation "mult_ldsched" 4
   (and (eq_attr "generic_sched" "yes")
        (and (eq_attr "ldsched" "yes") 
-	    (and (eq_attr "tune"
-		  "!strongarm,strongarm110,strongarm1100,strongarm1110")
+	    (and (eq_attr "tune" "!strongarm")
 	         (ior (eq_attr "mul32" "yes")
 		      (eq_attr "mul64" "yes")))))
   "core*4")
diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index cea98669111..8d6d2395b84 100644
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -498,6 +498,16 @@  struct arm_build_target
 
 extern struct arm_build_target arm_active_target;
 
+/* Table entry for a CPU alias.  */
+struct cpu_alias
+{
+  /* The alias name.  */
+  const char *const name;
+  /* True if the name should be displayed in help text listing cpu names.  */
+  bool visible;
+};
+
+/* Table entry for an architectural feature extension.  */
 struct cpu_arch_extension
 {
   /* Feature name.  */
@@ -511,6 +521,7 @@  struct cpu_arch_extension
   const enum isa_feature isa_bits[isa_num_bits];
 };
 
+/* Common elements of both CPU and architectural options.  */
 struct cpu_arch_option
 {
   /* Name for this option.  */
@@ -521,6 +532,7 @@  struct cpu_arch_option
   enum isa_feature isa_bits[isa_num_bits];
 };
 
+/* Table entry for an architecture entry.  */
 struct arch_option
 {
   /* Common option fields.  */
@@ -535,10 +547,13 @@  struct arch_option
   enum processor_type tune_id;
 };
 
+/* Table entry for a CPU entry.  */
 struct cpu_option
 {
   /* Common option fields.  */
   cpu_arch_option common;
+  /* List of aliases for this CPU.  */
+  const struct cpu_alias *aliases;
   /* Architecture upon which this CPU is based.  */
   enum arch_type arch;
 };
diff --git a/gcc/config/arm/arm-tables.opt b/gcc/config/arm/arm-tables.opt
index eacee746a39..623b79f3322 100644
--- a/gcc/config/arm/arm-tables.opt
+++ b/gcc/config/arm/arm-tables.opt
@@ -33,15 +33,6 @@  Enum(processor_type) String(arm810) Value( TARGET_CPU_arm810)
 EnumValue
 Enum(processor_type) String(strongarm) Value( TARGET_CPU_strongarm)
 
-EnumValue
-Enum(processor_type) String(strongarm110) Value( TARGET_CPU_strongarm110)
-
-EnumValue
-Enum(processor_type) String(strongarm1100) Value( TARGET_CPU_strongarm1100)
-
-EnumValue
-Enum(processor_type) String(strongarm1110) Value( TARGET_CPU_strongarm1110)
-
 EnumValue
 Enum(processor_type) String(fa526) Value( TARGET_CPU_fa526)
 
diff --git a/gcc/config/arm/arm-tune.md b/gcc/config/arm/arm-tune.md
index f64c1ef176d..47dc516e2a7 100644
--- a/gcc/config/arm/arm-tune.md
+++ b/gcc/config/arm/arm-tune.md
@@ -22,7 +22,6 @@ 
 
 (define_attr "tune"
 	"arm8,arm810,strongarm,
-	strongarm110,strongarm1100,strongarm1110,
 	fa526,fa626,arm7tdmi,
 	arm7tdmis,arm710t,arm720t,
 	arm740t,arm9,arm9tdmi,
diff --git a/gcc/config/arm/parsecpu.awk b/gcc/config/arm/parsecpu.awk
index aabe1b0c64c..ba2dee5fdcb 100644
--- a/gcc/config/arm/parsecpu.awk
+++ b/gcc/config/arm/parsecpu.awk
@@ -261,6 +261,18 @@  function gen_comm_data () {
 	    print "  { NULL, false, false, {isa_nobit}}"
 	    print "};\n"
 	}
+
+	if (cpus[n] in cpu_aliases) {
+	    print "static const cpu_alias cpu_aliastab_" \
+		cpu_cnames[cpus[n]] "[] = {"
+	    naliases = split (cpu_aliases[cpus[n]], aliases)
+	    for (alias = 1; alias <= naliases; alias++) {
+		print "  { \"" aliases[alias] "\", " \
+		    cpu_alias_visible[cpus[n],aliases[alias]] "},"
+	    }
+	    print "  { NULL, false}"
+	    print "};\n"
+	}
     }
 
     print "const cpu_option all_cores[] ="
@@ -295,12 +307,16 @@  function gen_comm_data () {
 	}
 	print_isa_bits_for(all_isa_bits, "      ")
 	print "\n    },"
+	# aliases
+	if (cpus[n] in cpu_aliases) {
+	    print "    cpu_aliastab_" cpu_cnames[cpus[n]] ","
+	} else print "    NULL,"
 	# arch
 	print "    TARGET_ARCH_" arch_cnames[feats[1]]
 	print "  },"
     }
 
-    print "  {{NULL, NULL, {isa_nobit}}, TARGET_ARCH_arm_none}"
+    print "  {{NULL, NULL, {isa_nobit}}, NULL, TARGET_ARCH_arm_none}"
     print "};"
 
     narchs = split (arch_list, archs)
@@ -486,13 +502,17 @@  function gen_opt () {
 function check_cpu (name) {
     exts = split (name, extensions, "+")
 
-    if (! (extensions[1] in cpu_cnames)) {
-	return "error"
+    cpu_name = extensions[1]
+    if (! (cpu_name in cpu_cnames)) {
+	if (! (cpu_name in cpu_all_aliases)) {
+	    return "error"
+	}
+	cpu_name = cpu_all_aliases[cpu_name]
     }
 
     for (n = 2; n <= exts; n++) {
-	if (!((extensions[1], extensions[n]) in cpu_opt_remove)	\
-	    && !((extensions[1], extensions[n]) in cpu_optaliases)) {
+	if (!((cpu_name, extensions[n]) in cpu_opt_remove)	\
+	    && !((cpu_name, extensions[n]) in cpu_optaliases)) {
 	    return "error"
 	}
     }
@@ -642,6 +662,12 @@  BEGIN {
     toplevel()
     cpu_name = $3
     parse_ok = 1
+    if (cpu_name in cpu_cnames) {
+	fatal(cpu_name " is already defined")
+    }
+    if (cpu_name in cpu_all_aliases) {
+	fatal(cpu_name " has already been defined as an alias")
+    }
 }
 
 /^[ 	]*cname / {
@@ -651,6 +677,33 @@  BEGIN {
     parse_ok = 1
 }
 
+/^[ 	]*alias / {
+    if (NF < 2) fatal("syntax: alias <name>+")
+    if (cpu_name == "") fatal("\"alias\" outside of cpu block")
+    alias_count = NF
+    for (n = 2; n <= alias_count; n++) {
+	visible = "true"
+	alias = $n
+	if (alias ~ /!.*/) {
+	    visible = "false"
+	    gsub(/^!/, "", alias)
+	}
+	if (alias in cpu_cnames) {
+	    fatal(alias " is already defined as a cpu name")
+	}
+	if (n == 2) {
+	    cpu_aliases[cpu_name] = alias
+	} else cpu_aliases[cpu_name] = cpu_aliases[cpu_name] " " alias
+	cpu_alias_visible[cpu_name,alias] = visible
+	if (alias in cpu_all_aliases) {
+	    fatal(alias " is already an alias for " cpu_all_aliases[alias])
+	}
+	cpu_all_aliases[alias] = cpu_name
+    }
+    cpu_has_alias[cpu_name] = 1
+    parse_ok = 1
+}
+
 /^[ 	]*tune for / {
     if (NF != 3) fatal("syntax: tune for <cpu-name>")
     if (cpu_name != "") {