Re: [PATCH 3/4] S390 -march=native related fixes

[Dominik Vogt <vogt at linux dot vnet dot ibm dot com>]

On Tue, Jul 21, 2015 at 07:05:27PM +0200, Ulrich Weigand wrote:
> Dominik Vogt wrote:
> > 	* config/s390/driver-native.c (s390_host_detect_local_cpu): Handle
> > 	processor capabilities with -march=native.
> > 	* config/s390/s390.h (MARCH_MTUNE_NATIVE_SPECS): Likewise.
> > 	(DRIVER_SELF_SPECS): Likewise.  Join specs for 31 and 64 bit.
> > 	* (S390_TARGET_BITS_STRING): Macro to simplify specs.
> (That last "*" is superfluous.)
> 
> This looks correct to me now, just a cosmetic comment:
> 
> > +/* Defaulting rules.  */
> > +#define DRIVER_SELF_SPECS					\
> > +  "%{!m31:%{!m64:-m" S390_TARGET_BITS_STRING "}} ",		\
> > +  MARCH_MTUNE_NATIVE_SPECS,					\
> > +  "%{!mesa:%{!mzarch:%{m31:-mesa}%{m64:-mzarch}}} ",		\
> > +  "%{!march=*:%{mesa:-march=g5}%{mzarch:-march=z900}} "
> 
> There's no need to add those spaces at the end -- the self specs
> are all independent string, they don't need to end in a space.
> 
> Also, I had thought to put MARCH_MTUNE_NATIVE_SPECS right at the
> top of list, like so:
> 
> #define DRIVER_SELF_SPECS					\
>   MARCH_MTUNE_NATIVE_SPECS,					\
>   "%{!m31:%{!m64:-m" S390_TARGET_BITS_STRING "}}",		\
>   "%{!mesa:%{!mzarch:%{m31:-mesa}%{m64:-mzarch}}}",		\
>   "%{!march=*:%{mesa:-march=g5}%{mzarch:-march=z900}}"
> 
> But there should not be any functional difference between the two,
> it just looks a bit nicer maybe.

The order was important in an earlier version of the patch, so
That's why I missed that.  Version 5 of the patch cleans up all
the things you've mentioned and also removes a superfluous newline.

Ciao

Dominik ^_^  ^_^

-- 

Dominik Vogt
IBM Germany

gcc/ChangeLog
 
	* config/s390/driver-native.c (s390_host_detect_local_cpu): Handle
	processor capabilities with -march=native.
	* config/s390/s390.h (MARCH_MTUNE_NATIVE_SPECS): Likewise.
	(DRIVER_SELF_SPECS): Likewise.  Join specs for 31 and 64 bit.
	(S390_TARGET_BITS_STRING): Macro to simplify specs.

>From 34a28f0cee71af2ec46cdc6f37485746750b2874 Mon Sep 17 00:00:00 2001
From: Dominik Vogt <vogt@linux.vnet.ibm.com>
Date: Mon, 6 Jul 2015 16:28:32 +0100
Subject: [PATCH 3/4] S390: Handle processor capabilities with -march=native.

---
 gcc/config/s390/driver-native.c | 143 ++++++++++++++++++++++++++++++++--------
 gcc/config/s390/s390.h          |  25 ++++---
 2 files changed, 127 insertions(+), 41 deletions(-)

diff --git a/gcc/config/s390/driver-native.c b/gcc/config/s390/driver-native.c
index 88c76bd..5f7fe0a 100644
--- a/gcc/config/s390/driver-native.c
+++ b/gcc/config/s390/driver-native.c
@@ -42,6 +42,16 @@ s390_host_detect_local_cpu (int argc, const char **argv)
   char buf[256];
   FILE *f;
   bool arch;
+  const char *options = "";
+  unsigned int has_features;
+  unsigned int has_processor;
+  unsigned int is_cpu_z9_109 = 0;
+  unsigned int has_highgprs = 0;
+  unsigned int has_dfp = 0;
+  unsigned int has_te = 0;
+  unsigned int has_vx = 0;
+  unsigned int has_opt_esa_zarch = 0;
+  int i;
 
   if (argc < 1)
     return NULL;
@@ -49,43 +59,120 @@ s390_host_detect_local_cpu (int argc, const char **argv)
   arch = strcmp (argv[0], "arch") == 0;
   if (!arch && strcmp (argv[0], "tune"))
     return NULL;
+  for (i = 1; i < argc; i++)
+    if (strcmp (argv[i], "mesa_mzarch") == 0)
+      has_opt_esa_zarch = 1;
 
   f = fopen ("/proc/cpuinfo", "r");
   if (f == NULL)
     return NULL;
 
-  while (fgets (buf, sizeof (buf), f) != NULL)
-    if (strncmp (buf, "processor", sizeof ("processor") - 1) == 0)
-      {
-	if (strstr (buf, "machine = 9672") != NULL)
-	  cpu = "g5";
-	else if (strstr (buf, "machine = 2064") != NULL
-		 || strstr (buf, "machine = 2066") != NULL)
-	  cpu = "z900";
-	else if (strstr (buf, "machine = 2084") != NULL
-		 || strstr (buf, "machine = 2086") != NULL)
-	  cpu = "z990";
-	else if (strstr (buf, "machine = 2094") != NULL
-		 || strstr (buf, "machine = 2096") != NULL)
-	  cpu = "z9-109";
-	else if (strstr (buf, "machine = 2097") != NULL
-		 || strstr (buf, "machine = 2098") != NULL)
-	  cpu = "z10";
-	else if (strstr (buf, "machine = 2817") != NULL
-		 || strstr (buf, "machine = 2818") != NULL)
-	  cpu = "z196";
-	else if (strstr (buf, "machine = 2827") != NULL
-		 || strstr (buf, "machine = 2828") != NULL)
-	  cpu = "zEC12";
-	else if (strstr (buf, "machine = 2964") != NULL)
-	  cpu = "z13";
-	break;
-      }
+  for (has_features = 0, has_processor = 0;
+       (has_features == 0 || has_processor == 0)
+	 && fgets (buf, sizeof (buf), f) != NULL; )
+    {
+      if (has_processor == 0 && strncmp (buf, "processor", 9) == 0)
+	{
+	  const char *p;
+	  long machine_id;
+
+	  p = strstr (buf, "machine = ");
+	  if (p == NULL)
+	    continue;
+	  p += 10;
+	  has_processor = 1;
+	  machine_id = strtol (p, NULL, 16);
+	  switch (machine_id)
+	    {
+	    case 0x9672:
+	      cpu = "g5";
+	      break;
+	    case 0x2064:
+	    case 0x2066:
+	      cpu = "z900";
+	      break;
+	    case 0x2084:
+	    case 0x2086:
+	      cpu = "z990";
+	      break;
+	    case 0x2094:
+	    case 0x2096:
+	      cpu = "z9-109";
+	      is_cpu_z9_109 = 1;
+	      break;
+	    case 0x2097:
+	    case 0x2098:
+	      cpu = "z10";
+	      break;
+	    case 0x2817:
+	    case 0x2818:
+	      cpu = "z196";
+	      break;
+	    case 0x2827:
+	    case 0x2828:
+	      cpu = "zEC12";
+	      break;
+	    case 0x2964:
+	      cpu = "z13";
+	      break;
+	    }
+	}
+      if (has_features == 0 && strncmp (buf, "features", 8) == 0)
+	{
+	  const char *p;
+
+	  p = strchr (buf, ':');
+	  if (p == NULL)
+	    continue;
+	  p++;
+	  while (*p != 0)
+	    {
+	      int i;
+
+	      while (ISSPACE (*p))
+		p++;
+	      for (i = 0; !ISSPACE (p[i]) && p[i] != 0; i++)
+		;
+	      if (i == 3 && strncmp (p, "dfp", 3) == 0)
+		has_dfp = 1;
+	      else if (i == 2 && strncmp (p, "te", 2) == 0)
+		has_te = 1;
+	      else if (i == 2 && strncmp (p, "vx", 2) == 0)
+		has_vx = 1;
+	      else if (i == 8 && strncmp (p, "highgprs", 8) == 0)
+		has_highgprs = 1;
+	      p += i;
+	    }
+	  has_features = 1;
+	}
+    }
 
   fclose (f);
 
   if (cpu == NULL)
     return NULL;
 
-  return concat ("-m", argv[0], "=", cpu, NULL);
+  if (arch)
+    {
+      const char *opt_htm = "";
+      const char *opt_vx = "";
+      const char *opt_esa_zarch = "";
+
+      /* We may switch off these cpu features but never switch the on
+	 explicitly.  This overrides options specified on the command line.  */
+      if (!has_te)
+	opt_htm = " -mno-htm";
+      if (!has_vx)
+	opt_vx = " -mno-vx";
+      /* However, we set -mzarch only if neither -mzarch nor -mesa are used on
+	 the command line.  This allows the user to switch to -mesa manually.
+      */
+      if (!has_opt_esa_zarch && has_highgprs)
+	opt_esa_zarch = " -mzarch";
+      options = concat (options, opt_htm, opt_vx, opt_esa_zarch, NULL);
+    }
+  if (has_dfp && is_cpu_z9_109)
+    cpu = "z9-ec";
+
+  return concat ("-m", argv[0], "=", cpu, options, NULL);
 }
diff --git a/gcc/config/s390/s390.h b/gcc/config/s390/s390.h
index f18b973..a0faf13 100644
--- a/gcc/config/s390/s390.h
+++ b/gcc/config/s390/s390.h
@@ -131,27 +131,26 @@ extern const char *s390_host_detect_local_cpu (int argc, const char **argv);
 # define EXTRA_SPEC_FUNCTIONS \
   { "local_cpu_detect", s390_host_detect_local_cpu },
 
-# define MARCH_MTUNE_NATIVE_SPECS				\
-  " %{march=native:%<march=native %:local_cpu_detect(arch)}"	\
-  " %{mtune=native:%<mtune=native %:local_cpu_detect(tune)}"
+#define MARCH_MTUNE_NATIVE_SPECS				\
+  "%{mtune=native:%<mtune=native %:local_cpu_detect(tune)} "	\
+  "%{march=native:%<march=native"				\
+  " %:local_cpu_detect(arch %{mesa|mzarch:mesa_mzarch})}"
 #else
 # define MARCH_MTUNE_NATIVE_SPECS ""
 #endif
 
-/* Defaulting rules.  */
 #ifdef DEFAULT_TARGET_64BIT
-#define DRIVER_SELF_SPECS					\
-  "%{!m31:%{!m64:-m64}}",					\
-  "%{!mesa:%{!mzarch:%{m31:-mesa}%{m64:-mzarch}}}",		\
-  "%{!march=*:%{mesa:-march=g5}%{mzarch:-march=z900}}",		\
-  MARCH_MTUNE_NATIVE_SPECS
+#define S390_TARGET_BITS_STRING "64"
 #else
+#define S390_TARGET_BITS_STRING "31"
+#endif
+
+/* Defaulting rules.  */
 #define DRIVER_SELF_SPECS					\
-  "%{!m31:%{!m64:-m31}}",					\
+  MARCH_MTUNE_NATIVE_SPECS,					\
+  "%{!m31:%{!m64:-m" S390_TARGET_BITS_STRING "}}",		\
   "%{!mesa:%{!mzarch:%{m31:-mesa}%{m64:-mzarch}}}",		\
-  "%{!march=*:%{mesa:-march=g5}%{mzarch:-march=z900}}",		\
-  MARCH_MTUNE_NATIVE_SPECS
-#endif
+  "%{!march=*:%{mesa:-march=g5}%{mzarch:-march=z900}}"
 
 /* Constants needed to control the TEST DATA CLASS (TDC) instruction.  */
 #define S390_TDC_POSITIVE_ZERO                     (1 << 11)
-- 
2.3.0