From 043f950abeb8dd915729d367561e9ed706b56a94 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Thu, 10 Nov 2022 02:50:52 +0700
Subject: [PATCH] sim: ppc: change spreg switch table generation to
 compile-time

Simplify the generator by always outputting the switch tables, and
leave the choice of whether to use them to the compiler via a -D
flag.
---
 sim/ppc/Makefile.in  |  6 ++++--
 sim/ppc/configure    |  2 +-
 sim/ppc/configure.ac |  2 +-
 sim/ppc/dgen.c       | 21 ++++++++++-----------
 4 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/sim/ppc/Makefile.in b/sim/ppc/Makefile.in
index 54e755e5bfe..8fed7da83f5 100644
--- a/sim/ppc/Makefile.in
+++ b/sim/ppc/Makefile.in
@@ -70,6 +70,7 @@ FLOAT_CFLAGS = @sim_float@
 MONITOR_CFLAGS = @sim_monitor@
 MODEL_CFLAGS = @sim_model@ @sim_default_model@ @sim_model_issue@
 TERMIO_CFLAGS = @sim_termio@
+SWITCH_CFLAGS = @sim_switch@
 CONFIG_CFLAGS = \
   $(SMP_CFLAGS) \
   $(XOR_ENDIAN_CFLAGS) \
@@ -79,7 +80,8 @@ CONFIG_CFLAGS = \
   $(FLOAT_CFLAGS) \
   $(MONITOR_CFLAGS) \
   $(MODEL_CFLAGS) \
-  $(TERMIO_CFLAGS)
+  $(TERMIO_CFLAGS) \
+  $(SWITCH_CFLAGS)
 SIM_FPU_CFLAGS = -DHAVE_COMMON_FPU -I../common -I${srcdir}/../common
 
 STD_CFLAGS	= $(CFLAGS) $(WERROR_CFLAGS) $(INLINE_CFLAGS) $(CONFIG_CFLAGS) $(WARN_CFLAGS) $(INCLUDES) $(INCGNU) $(SIM_FPU_CFLAGS)
@@ -99,7 +101,7 @@ IGEN_FILTER = @sim_filter@
 IGEN_ICACHE = @sim_icache@
 IGEN_SMP = @sim_igen_smp@
 IGEN_LINE_NR = @sim_line_nr@
-DGEN_FLAGS = @sim_switch@
+DGEN_FLAGS =
 
 IGEN_FLAGS = \
 	$(IGEN_DECODE_MECHANISM) \
diff --git a/sim/ppc/configure b/sim/ppc/configure
index 39a7ac934ce..41dafffa5d2 100755
--- a/sim/ppc/configure
+++ b/sim/ppc/configure
@@ -3498,7 +3498,7 @@ fi
 # Check whether --enable-sim-switch was given.
 if test "${enable_sim_switch+set}" = set; then :
   enableval=$enable_sim_switch; case "${enableval}" in
-  yes)	sim_switch="-s";;
+  yes)	sim_switch="-DWITH_SPREG_SWITCH_TABLE";;
   no)	sim_switch="";;
   *)	as_fn_error $? "\"--enable-sim-switch does not take a value\"" "$LINENO" 5; sim_switch="";;
 esac
diff --git a/sim/ppc/configure.ac b/sim/ppc/configure.ac
index cd9edd0de4c..5260fa0ba7a 100644
--- a/sim/ppc/configure.ac
+++ b/sim/ppc/configure.ac
@@ -345,7 +345,7 @@ fi])dnl
 AC_ARG_ENABLE(sim-switch,
 [  --enable-sim-switch			Use a switch instead of a table for instruction call.],
 [case "${enableval}" in
-  yes)	sim_switch="-s";;
+  yes)	sim_switch="-DWITH_SPREG_SWITCH_TABLE";;
   no)	sim_switch="";;
   *)	AC_MSG_ERROR("--enable-sim-switch does not take a value"); sim_switch="";;
 esac
diff --git a/sim/ppc/dgen.c b/sim/ppc/dgen.c
index 8a17700820e..73f8d7d4582 100644
--- a/sim/ppc/dgen.c
+++ b/sim/ppc/dgen.c
@@ -39,7 +39,6 @@
 
 /****************************************************************/
 
-int spreg_lookup_table = 1;
 enum {
   nr_of_sprs = 1024,
 };
@@ -185,6 +184,7 @@ gen_spreg_c(spreg_table *table, lf *file)
   spreg_table_entry *entry;
   char **attribute;
   int spreg_nr;
+  int spreg_lookup_table;
 
   lf_print__gnu_copyleft(file);
   lf_printf(file, "\n");
@@ -229,13 +229,11 @@ gen_spreg_c(spreg_table *table, lf *file)
     }
     lf_printf(file, "spr_%s(sprs spr)\n", *attribute);
     lf_printf(file, "{\n");
-    if (spreg_lookup_table
-	|| strcmp(*attribute, "name") == 0
-	|| strcmp(*attribute, "index") == 0)
-      lf_printf(file, "  return spr_info[spr].%s;\n",
-		*attribute);
-    else {
+    spreg_lookup_table = !(strcmp(*attribute, "name") == 0
+			   || strcmp(*attribute, "index") == 0);
+    if (spreg_lookup_table) {
       spreg_table_entry *entry;
+      lf_printf(file, "#ifdef WITH_SPREG_SWITCH_TABLE\n");
       lf_printf(file, "  switch (spr) {\n");
       for (entry = table->sprs; entry != NULL; entry = entry->next) {
 	if (strcmp(*attribute, "is_valid") == 0) {
@@ -261,7 +259,12 @@ gen_spreg_c(spreg_table *table, lf *file)
 	lf_printf(file, "    return 1;\n");
       lf_printf(file, "  }\n");
       lf_printf(file, "  return 0;\n");
+      lf_printf(file, "#else\n");
     }
+    lf_printf(file, "  return spr_info[spr].%s;\n",
+	      *attribute);
+    if (spreg_lookup_table)
+      lf_printf(file, "#endif\n");
     lf_printf(file, "}\n");
   }
 
@@ -288,7 +291,6 @@ main(int argc,
 
   if (argc <= 1) {
     printf("Usage: dgen ...\n");
-    printf("-s  Use switch instead of table\n");
     printf("-n <file-name>  Use this as cpp line numbering name\n");
     printf("-h  Output header file\n");
     printf("-p <spreg-file>  Output spreg.h(P) or spreg.c(p)\n");
@@ -301,9 +303,6 @@ main(int argc,
     fprintf(stderr, "\t-%c %s\n", ch, ( optarg ? optarg : ""));
 #endif
     switch(ch) {
-    case 's':
-      spreg_lookup_table = 0;
-      break;
     case 'r':
       sprs = spreg_table_load(optarg);
       break;
-- 
2.30.2