aarch64: Add +sme

This patch adds the +sme ISA feature and requires it to be present
when compiling arm_streaming code.  (arm_streaming_compatible code
does not necessarily assume the presence of SME.  It just has to
work when SME is present and streaming mode is enabled.)

gcc/
	* doc/invoke.texi: Document SME.
	* doc/sourcebuild.texi: Document aarch64_sve.
	* config/aarch64/aarch64-option-extensions.def (sme): Define.
	* config/aarch64/aarch64.h (AARCH64_ISA_SME): New macro.
	(TARGET_SME): Likewise.
	* config/aarch64/aarch64.cc (aarch64_override_options_internal):
	Ensure that SME is present when compiling streaming code.

gcc/testsuite/
	* lib/target-supports.exp (check_effective_target_aarch64_sme): New
	target test.
	* gcc.target/aarch64/sme/aarch64-sme.exp: Force SME to be enabled
	if it isn't by default.
	* g++.target/aarch64/sme/aarch64-sme.exp: Likewise.
	* gcc.target/aarch64/sme/streaming_mode_3.c: New test.

10 files changed, 157 insertions, 4 deletions

diff --git a/gcc/config/aarch64/aarch64-option-extensions.def b/gcc/config/aarch64/aarch64-option-extensions.def
index 825f3bf..fb9ff1b 100644
--- a/gcc/config/aarch64/aarch64-option-extensions.def
+++ b/gcc/config/aarch64/aarch64-option-extensions.def
@@ -151,4 +151,6 @@ AARCH64_OPT_EXTENSION("mops", MOPS, (), (), (), "")
 
 AARCH64_OPT_EXTENSION("cssc", CSSC, (), (), (), "cssc")
 
+AARCH64_OPT_EXTENSION("sme", SME, (BF16, SVE2), (), (), "sme")
+
 #undef AARCH64_OPT_EXTENSION
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index b60728b..3792f1e 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -9328,6 +9328,23 @@ aarch64_fixed_condition_code_regs (unsigned int *p1, unsigned int *p2)
   return true;
 }
 
+/* Implement TARGET_START_CALL_ARGS.  */
+
+static void
+aarch64_start_call_args (cumulative_args_t ca_v)
+{
+  CUMULATIVE_ARGS *ca = get_cumulative_args (ca_v);
+
+  if (!TARGET_SME && (ca->isa_mode & AARCH64_FL_SM_ON))
+    {
+      error ("calling a streaming function requires the ISA extension %qs",
+	     "sme");
+      inform (input_location, "you can enable %qs using the command-line"
+	      " option %<-march%>, or by using the %<target%>"
+	      " attribute or pragma", "sme");
+    }
+}
+
 /* This function is used by the call expanders of the machine description.
    RESULT is the register in which the result is returned.  It's NULL for
    "call" and "sibcall".
@@ -16147,6 +16164,19 @@ aarch64_override_options_internal (struct gcc_options *opts)
       && !fixed_regs[R18_REGNUM])
     error ("%<-fsanitize=shadow-call-stack%> requires %<-ffixed-x18%>");
 
+  if ((opts->x_aarch64_isa_flags & AARCH64_FL_SM_ON)
+      && !(opts->x_aarch64_isa_flags & AARCH64_FL_SME))
+    {
+      error ("streaming functions require the ISA extension %qs", "sme");
+      inform (input_location, "you can enable %qs using the command-line"
+	      " option %<-march%>, or by using the %<target%>"
+	      " attribute or pragma", "sme");
+      opts->x_target_flags &= ~MASK_GENERAL_REGS_ONLY;
+      auto new_flags = (opts->x_aarch64_asm_isa_flags
+			| feature_deps::SME ().enable);
+      aarch64_set_asm_isa_flags (opts, new_flags);
+    }
+
   initialize_aarch64_code_model (opts);
   initialize_aarch64_tls_size (opts);
   aarch64_tpidr_register = opts->x_aarch64_tpidr_reg;
@@ -26248,6 +26278,9 @@ aarch64_run_selftests (void)
 #undef TARGET_FUNCTION_VALUE_REGNO_P
 #define TARGET_FUNCTION_VALUE_REGNO_P aarch64_function_value_regno_p
 
+#undef TARGET_START_CALL_ARGS
+#define TARGET_START_CALL_ARGS aarch64_start_call_args
+
 #undef TARGET_GIMPLE_FOLD_BUILTIN
 #define TARGET_GIMPLE_FOLD_BUILTIN aarch64_gimple_fold_builtin
 
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 08d135d..aa908ce 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -214,6 +214,7 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE = AARCH64_FL_SM_OFF;
 #define AARCH64_ISA_SVE2_BITPERM  (aarch64_isa_flags & AARCH64_FL_SVE2_BITPERM)
 #define AARCH64_ISA_SVE2_SHA3	   (aarch64_isa_flags & AARCH64_FL_SVE2_SHA3)
 #define AARCH64_ISA_SVE2_SM4	   (aarch64_isa_flags & AARCH64_FL_SVE2_SM4)
+#define AARCH64_ISA_SME		   (aarch64_isa_flags & AARCH64_FL_SME)
 #define AARCH64_ISA_V8_3A	   (aarch64_isa_flags & AARCH64_FL_V8_3A)
 #define AARCH64_ISA_DOTPROD	   (aarch64_isa_flags & AARCH64_FL_DOTPROD)
 #define AARCH64_ISA_AES	           (aarch64_isa_flags & AARCH64_FL_AES)
@@ -293,6 +294,10 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE = AARCH64_FL_SM_OFF;
 /* SVE2 SM4 instructions, enabled through +sve2-sm4.  */
 #define TARGET_SVE2_SM4 (AARCH64_ISA_SVE2_SM4)
 
+/* SME instructions, enabled through +sme.  Note that this does not
+   imply anything about the state of PSTATE.SM.  */
+#define TARGET_SME (AARCH64_ISA_SME)
+
 /* ARMv8.3-A features.  */
 #define TARGET_ARMV8_3	(AARCH64_ISA_V8_3A)
 
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 681e3f3..b138a74 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -21273,6 +21273,8 @@ Enable the Flag Manipulation instructions Extension.
 Enable the Pointer Authentication Extension.
 @item cssc
 Enable the Common Short Sequence Compression instructions.
+@item sme
+Enable the Scalable Matrix Extension.
 
 @end table
 
diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index d3f68f3..123e735 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -2316,6 +2316,8 @@ AArch64 target which generates instruction sequences for big endian.
 @item aarch64_small_fpic
 Binutils installed on test system supports relocation types required by -fpic
 for AArch64 small memory model.
+@item aarch64_sme
+AArch64 target that generates instructions for SME.
 @item aarch64_sve_hw
 AArch64 target that is able to generate and execute SVE code (regardless of
 whether it does so by default).
diff --git a/gcc/testsuite/g++.target/aarch64/sme/aarch64-sme.exp b/gcc/testsuite/g++.target/aarch64/sme/aarch64-sme.exp
index 72fcd0b..1c3e69c 100644
--- a/gcc/testsuite/g++.target/aarch64/sme/aarch64-sme.exp
+++ b/gcc/testsuite/g++.target/aarch64/sme/aarch64-sme.exp
@@ -30,10 +30,16 @@ load_lib g++-dg.exp
 # Initialize `dg'.
 dg-init
 
-aarch64-with-arch-dg-options "" {
+if { [check_effective_target_aarch64_sme] } {
+    set sme_flags ""
+} else {
+    set sme_flags "-march=armv9-a+sme"
+}
+
+aarch64-with-arch-dg-options $sme_flags {
     # Main loop.
     dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cCS\]]] \
-	"" ""
+	"" $sme_flags
 }
 
 # All done.
diff --git a/gcc/testsuite/gcc.target/aarch64/sme/aarch64-sme.exp b/gcc/testsuite/gcc.target/aarch64/sme/aarch64-sme.exp
index c990e59..011310e 100644
--- a/gcc/testsuite/gcc.target/aarch64/sme/aarch64-sme.exp
+++ b/gcc/testsuite/gcc.target/aarch64/sme/aarch64-sme.exp
@@ -30,10 +30,16 @@ load_lib gcc-dg.exp
 # Initialize `dg'.
 dg-init
 
-aarch64-with-arch-dg-options "" {
+if { [check_effective_target_aarch64_sme] } {
+    set sme_flags ""
+} else {
+    set sme_flags "-march=armv9-a+sme"
+}
+
+aarch64-with-arch-dg-options $sme_flags {
     # Main loop.
     dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cCS\]]] \
-	"" ""
+	"" $sme_flags
 }
 
 # All done.
diff --git a/gcc/testsuite/gcc.target/aarch64/sme/streaming_mode_3.c b/gcc/testsuite/gcc.target/aarch64/sme/streaming_mode_3.c
new file mode 100644
index 0000000..45ec923
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sme/streaming_mode_3.c
@@ -0,0 +1,63 @@
+// { dg-options "" }
+
+#pragma GCC target "+nosme"
+
+void sc_a () [[arm::streaming_compatible]] {}
+void s_a () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+void ns_a () {}
+
+void sc_b () [[arm::streaming_compatible]] {}
+void ns_b () {}
+void s_b () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+
+void sc_c () [[arm::streaming_compatible]] {}
+void sc_d () [[arm::streaming_compatible]] {}
+
+void s_c () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+void s_d () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+
+void ns_c () {}
+void ns_d () {}
+
+void sc_e () [[arm::streaming_compatible]];
+void s_e () [[arm::streaming]];
+void ns_e ();
+
+#pragma GCC target "+sme"
+
+void sc_f () [[arm::streaming_compatible]] {}
+void s_f () [[arm::streaming]] {}
+void ns_f () {}
+
+void sc_g () [[arm::streaming_compatible]] {}
+void ns_g () {}
+void s_g () [[arm::streaming]] {}
+
+void sc_h () [[arm::streaming_compatible]] {}
+void sc_i () [[arm::streaming_compatible]] {}
+
+void s_h () [[arm::streaming]] {}
+void s_i () [[arm::streaming]] {}
+
+void ns_h () {}
+void ns_i () {}
+
+void sc_j () [[arm::streaming_compatible]];
+void s_j () [[arm::streaming]];
+void ns_j ();
+
+#pragma GCC target "+sme"
+
+void sc_k () [[arm::streaming_compatible]] {}
+
+#pragma GCC target "+nosme"
+#pragma GCC target "+sme"
+
+void s_k () [[arm::streaming]] {}
+
+#pragma GCC target "+nosme"
+#pragma GCC target "+sme"
+
+void ns_k () {}
+
+#pragma GCC target "+nosme"
diff --git a/gcc/testsuite/gcc.target/aarch64/sme/streaming_mode_4.c b/gcc/testsuite/gcc.target/aarch64/sme/streaming_mode_4.c
new file mode 100644
index 0000000..50e92f2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sme/streaming_mode_4.c
@@ -0,0 +1,22 @@
+// { dg-options "-mgeneral-regs-only" }
+
+void sc_a () [[arm::streaming_compatible]] {}
+void s_a () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+void ns_a () {}
+
+void sc_b () [[arm::streaming_compatible]] {}
+void ns_b () {}
+void s_b () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+
+void sc_c () [[arm::streaming_compatible]] {}
+void sc_d () [[arm::streaming_compatible]] {}
+
+void s_c () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+void s_d () [[arm::streaming]] {} // { dg-error "streaming functions require the ISA extension 'sme'" }
+
+void ns_c () {}
+void ns_d () {}
+
+void sc_e () [[arm::streaming_compatible]];
+void s_e () [[arm::streaming]];
+void ns_e ();
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 83eb08b..c9bbab9 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -4386,6 +4386,18 @@ proc aarch64_sve_bits { } {
     }]
 }
 
+# Return 1 if this is an AArch64 target that generates instructions for SME.
+proc check_effective_target_aarch64_sme { } {
+    if { ![istarget aarch64*-*-*] } {
+	return 0
+    }
+    return [check_no_compiler_messages aarch64_sme assembly {
+	#if !defined (__ARM_FEATURE_SME)
+	#error FOO
+	#endif
+    }]
+}
+
 # Return 1 if this is a compiler supporting ARC atomic operations
 proc check_effective_target_arc_atomic { } {
     return [check_no_compiler_messages arc_atomic assembly {