[APX EGPR] Map reg/mem constraints in inline asm to non-EGPR constraint.

In inline asm, we do not know if the insn can use EGPR, so disable EGPR
usage by default via mapping the common reg/mem constraint to non-EGPR
constraints.

The full list of mapping goes like

  "g" -> "jrjmi"
  "r" -> "jr"
  "m" -> "jm"
  "<" -> "j<"
  ">" -> "j>"
  "o" -> "jo"
  "V" -> "jV"
  "p" -> "jp"
  "Bm" -> "ja

For memory constraints, we add an option -mapx-inline-asm-use-gpr32
to allow/disallow gpr32 usage in any memory related constraints, as
base_reg_class/index_reg_class cannot aware whether the asm insn
support gpr32 or not.

gcc/ChangeLog:

	* config/i386/i386.cc (map_egpr_constraints): New funciton to
	map common constraints to EGPR prohibited constraints.
	(ix86_md_asm_adjust): Calls map_egpr_constraints.
	* config/i386/i386.opt: Add option mapx-inline-asm-use-gpr32.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/apx-inline-gpr-norex2.c: New test.

Co-authored-by: Hongyu Wang <hongyu.wang@intel.com>
Co-authored-by: Hongtao Liu <hongtao.liu@intel.com>

3 files changed, 122 insertions, 0 deletions

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index ada9ac8..a983513 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -17,6 +17,7 @@ You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
+#define INCLUDE_STRING
 #define IN_TARGET_CODE 1
 
 #include "config.h"
@@ -23168,6 +23169,93 @@ ix86_c_mode_for_suffix (char suffix)
   return VOIDmode;
 }
 
+/* Helper function to map common constraints to non-EGPR ones.
+   All related constraints have h prefix, and h plus Upper letter
+   means the constraint is strictly EGPR enabled, while h plus
+   lower letter indicates the constraint is strictly gpr16 only.
+
+   Specially for "g" constraint, split it to rmi as there is
+   no corresponding general constraint define for backend.
+
+   Here is the full list to map constraints that may involve
+   gpr to h prefixed.
+
+   "g" -> "jrjmi"
+   "r" -> "jr"
+   "m" -> "jm"
+   "<" -> "j<"
+   ">" -> "j>"
+   "o" -> "jo"
+   "V" -> "jV"
+   "p" -> "jp"
+   "Bm" -> "ja"
+*/
+
+static void map_egpr_constraints (vec<const char *> &constraints)
+{
+  for (size_t i = 0; i < constraints.length(); i++)
+    {
+      const char *cur = constraints[i];
+
+      if (startswith (cur, "=@cc"))
+	continue;
+
+      int len = strlen (cur);
+      auto_vec<char> buf;
+
+      for (int j = 0; j < len; j++)
+	{
+	  switch (cur[j])
+	    {
+	    case 'g':
+	      buf.safe_push ('j');
+	      buf.safe_push ('r');
+	      buf.safe_push ('j');
+	      buf.safe_push ('m');
+	      buf.safe_push ('i');
+	      break;
+	    case 'r':
+	    case 'm':
+	    case '<':
+	    case '>':
+	    case 'o':
+	    case 'V':
+	    case 'p':
+	      buf.safe_push ('j');
+	      buf.safe_push (cur[j]);
+	      break;
+	    case 'B':
+	      if (cur[j + 1] == 'm')
+		{
+		  buf.safe_push ('j');
+		  buf.safe_push ('a');
+		  j++;
+		}
+	      else
+		{
+		  buf.safe_push (cur[j]);
+		  buf.safe_push (cur[j + 1]);
+		  j++;
+		}
+	      break;
+	    case 'T':
+	    case 'Y':
+	    case 'W':
+	    case 'j':
+	      buf.safe_push (cur[j]);
+	      buf.safe_push (cur[j + 1]);
+	      j++;
+	      break;
+	    default:
+	      buf.safe_push (cur[j]);
+	      break;
+	    }
+	}
+      buf.safe_push ('\0');
+      constraints[i] = xstrdup (buf.address ());
+    }
+}
+
 /* Worker function for TARGET_MD_ASM_ADJUST.
 
    We implement asm flag outputs, and maintain source compatibility
@@ -23182,6 +23270,10 @@ ix86_md_asm_adjust (vec<rtx> &outputs, vec<rtx> & /*inputs*/,
   bool saw_asm_flag = false;
 
   start_sequence ();
+
+  if (TARGET_APX_EGPR && !ix86_apx_inline_asm_use_gpr32)
+    map_egpr_constraints (constraints);
+
   for (unsigned i = 0, n = outputs.length (); i < n; ++i)
     {
       const char *con = constraints[i];
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index d89b5bb..d4a7b7e 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -1335,3 +1335,8 @@ Enum(apx_features) String(ndd) Value(apx_ndd) Set(4)
 
 EnumValue
 Enum(apx_features) String(all) Value(apx_all) Set(1)
+
+mapx-inline-asm-use-gpr32
+Target Var(ix86_apx_inline_asm_use_gpr32) Init(0)
+Enable GPR32 in inline asm when APX_EGPR enabled, do not
+hook reg or mem constraint in inline asm to GPR16.
diff --git a/gcc/testsuite/gcc.target/i386/apx-inline-gpr-norex2.c b/gcc/testsuite/gcc.target/i386/apx-inline-gpr-norex2.c
new file mode 100644
index 0000000..ffd8f95
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/apx-inline-gpr-norex2.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mapxf -m64" } */
+
+typedef unsigned int u32;
+typedef unsigned long long u64;
+
+void constraint_test ()
+{
+  register u64 *r16 __asm__("%r16");
+  register u64 r17 __asm__("%r17");
+  u64 *addr = r16;
+  
+  __asm__ __volatile__ ("test_mapping_g_m %0, %%rax" : : "g" (r16) : "rax");
+  __asm__ __volatile__ ("test_mapping_g_r %0, %%rax" : : "g" (r17) : "rax");
+  __asm__ __volatile__ ("test_mapping_m %0, %%rax" : : "m" (addr) : "rax");
+  __asm__ __volatile__ ("test_mapping_r %0, %%rax" : : "r" (r17) : "rax");
+  __asm__ __volatile__ ("test_mapping_rm %0, %%rax" : "=r,m" (r16) : : "rax");
+}
+
+/* { dg-final { scan-assembler-not "test_mapping_g_m %r16, %rax" } } */
+/* { dg-final { scan-assembler-not "test_mapping_g_r %r17, %rax" } } */
+/* { dg-final { scan-assembler-not "test_mapping_m %r16, %rax" } } */
+/* { dg-final { scan-assembler-not "test_mapping_r %r17, %rax" } } */
+/* { dg-final { scan-assembler-not "test_mapping_rm %r16, %rax" } } */
+