[PATCH] x86: Don't enable UINTR in 32-bit mode

[PATCH] x86: Don't enable UINTR in 32-bit mode

[H.J. Lu]

UINTR is available only in 64-bit mode.  Since the codegen target is
unknown when the the gcc driver is processing -march=native, to properly
handle UINTR for -march=native:

1. Add an undocumented option, -muintr-native.
2. Update the gcc driver to pass -muintr-native with -march=native if
UINTR is available.
3. Change ix86_option_override_internal to
   a. Turn on UINTR in 64-bit mode for -muintr-native.
   b. Enable UINTR only in 64-bit mode for -march=CPU when PTA_CPU
   includes PTA_UINTR.

gcc/

	PR target/101395
	* config/i386/driver-i386.c (host_detect_local_cpu): Add
	-muintr-native for FEATURE_UINTR.
	* config/i386/i386-options.c (ix86_option_override_internal):
	Move -muintr check after -march processing and turn on UINTR in
	64-bit mode for -muintr-native if it has not been disabled
	explicitly.
	(DEF_PTA): Skip PTA_UINTR if not in 64-bit mode.
	* config/i386/i386.opt (muintr-native): New.  Undocumented to
	enable -muintr only in 64-bit mode with -march=native.

gcc/testsuite/

	PR target/101395
	* gcc.target/i386/pr101395-1.c: New test.
	* gcc.target/i386/pr101395-2.c: Likewise.
	* gcc.target/i386/pr101395-3.c: Likewise.
---
 gcc/config/i386/driver-i386.c              | 10 ++++++++--
 gcc/config/i386/i386-options.c             | 14 +++++++++++---
 gcc/config/i386/i386.opt                   |  4 ++++
 gcc/testsuite/gcc.target/i386/pr101395-1.c | 12 ++++++++++++
 gcc/testsuite/gcc.target/i386/pr101395-2.c | 22 ++++++++++++++++++++++
 gcc/testsuite/gcc.target/i386/pr101395-3.c |  6 ++++++
 6 files changed, 63 insertions(+), 5 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr101395-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr101395-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr101395-3.c

diff --git a/gcc/config/i386/driver-i386.c b/gcc/config/i386/driver-i386.c
index dd9236616b4..7ade90a088d 100644
--- a/gcc/config/i386/driver-i386.c
+++ b/gcc/config/i386/driver-i386.c
@@ -804,8 +804,14 @@ const char *host_detect_local_cpu (int argc, const char **argv)
 	if (isa_names_table[i].option)
 	  {
 	    if (has_feature (isa_names_table[i].feature))
-	      options = concat (options, " ",
-				isa_names_table[i].option, NULL);
+	      {
+		const char *option;
+		if (isa_names_table[i].feature == FEATURE_UINTR)
+		  option = "-muintr-native";
+		else
+		  option = isa_names_table[i].option;
+		options = concat (options, " ", option, NULL);
+	      }
 	    else
 	      options = concat (options, neg_option,
 				isa_names_table[i].option + 2, NULL);
diff --git a/gcc/config/i386/i386-options.c b/gcc/config/i386/i386-options.c
index 7a35c468da3..6b12f030f0c 100644
--- a/gcc/config/i386/i386-options.c
+++ b/gcc/config/i386/i386-options.c
@@ -1920,9 +1920,6 @@ ix86_option_override_internal (bool main_args_p,
       opts->x_ix86_stringop_alg = no_stringop;
     }
 
-  if (TARGET_UINTR && !TARGET_64BIT)
-    error ("%<-muintr%> not supported for 32-bit code");
-
   if (!opts->x_ix86_arch_string)
     opts->x_ix86_arch_string
       = TARGET_64BIT_P (opts->x_ix86_isa_flags)
@@ -2109,6 +2106,7 @@ ix86_option_override_internal (bool main_args_p,
 #define DEF_PTA(NAME) \
 	if (((processor_alias_table[i].flags & PTA_ ## NAME) != 0) \
 	    && PTA_ ## NAME != PTA_64BIT \
+	    && (TARGET_64BIT || PTA_ ## NAME != PTA_UINTR) \
 	    && !TARGET_EXPLICIT_ ## NAME ## _P (opts)) \
 	  SET_TARGET_ ## NAME (opts);
 #include "i386-isa.def"
@@ -2184,6 +2182,16 @@ ix86_option_override_internal (bool main_args_p,
       XDELETEVEC (s);
     }
 
+  if (TARGET_64BIT)
+    {
+      /* Turn on UINTR in 64-bit mode for -muintr-native if it has not
+	 been set explicitly.  */
+      if (ix86_uintr_native && !TARGET_EXPLICIT_UINTR_P (opts))
+	SET_TARGET_UINTR (opts);
+    }
+  else if (TARGET_UINTR)
+    error ("%<-muintr%> not supported for 32-bit code");
+
   ix86_arch_mask = HOST_WIDE_INT_1U << ix86_arch;
   for (i = 0; i < X86_ARCH_LAST; ++i)
     ix86_arch_features[i] = !!(initial_ix86_arch_features[i] & ix86_arch_mask);
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 7b8547bb1c3..5923bbfb40e 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -802,6 +802,10 @@ muintr
 Target Mask(ISA2_UINTR) Var(ix86_isa_flags2) Save
 Support UINTR built-in functions and code generation.
 
+; Used to enable -muintr only in 64-bit mode with -march=native.
+muintr-native
+Target Undocumented RejectNegative Var(ix86_uintr_native)
+
 msgx
 Target Mask(ISA2_SGX) Var(ix86_isa_flags2) Save
 Support SGX built-in functions and code generation.
diff --git a/gcc/testsuite/gcc.target/i386/pr101395-1.c b/gcc/testsuite/gcc.target/i386/pr101395-1.c
new file mode 100644
index 00000000000..74c8bfe891a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr101395-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=sapphirerapids" } */
+
+#ifdef __x86_64__
+# ifndef __UINTR__
+#  error UINTR is not enabled for Sapphirerapids
+# endif
+#else
+# ifdef __UINTR__
+#  error UINTR is not usable in 32-bit mode
+# endif
+#endif
diff --git a/gcc/testsuite/gcc.target/i386/pr101395-2.c b/gcc/testsuite/gcc.target/i386/pr101395-2.c
new file mode 100644
index 00000000000..f2b677f8c80
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr101395-2.c
@@ -0,0 +1,22 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -march=native" } */
+
+int
+main ()
+{
+  if (__builtin_cpu_supports ("uintr"))
+    {
+#ifdef __x86_64__
+# ifndef __UINTR__
+      __builtin_abort ();
+# endif
+#else
+# ifdef __UINTR__
+      __builtin_abort ();
+# endif
+#endif
+      return 0;
+    }
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr101395-3.c b/gcc/testsuite/gcc.target/i386/pr101395-3.c
new file mode 100644
index 00000000000..bc6ab423c93
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr101395-3.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=native -mno-uintr" } */
+
+#ifdef __UINTR__
+# error UINTR should be disabled
+#endif
-- 
2.31.1