MIPS16/GCC: Emit bounds checking as RTL in `casesi'

	gcc/
	* config/mips/mips.md (MIPS16_T_REGNUM): Remove constant.
	(casesi): Emit bounds checking as RTL.
	(casesi_internal_mips16_<mode>): Remove bounds checking.

	gcc/testsuite/
	* gcc.target/mips/data-sym-jump.c: Adjust for whitespace changes.
	* gcc.target/mips/pr51513-1.c: New test.
	* gcc.target/mips/pr51513-2.c: New test.

From-SVN: r249207

6 files changed, 141 insertions, 37 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 09435d0..2d5110c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-06-14  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* config/mips/mips.md (MIPS16_T_REGNUM): Remove constant.
+	(casesi): Emit bounds checking as RTL.
+	(casesi_internal_mips16_<mode>): Remove bounds checking.
+
 2017-06-14  Max Filippov  <jcmvbkbc@gmail.com>
 
 	* config/xtensa/xtensa.c (xtensa_option_override): Append
diff --git a/gcc/config/mips/mips.md b/gcc/config/mips/mips.md
index 28e0a44..971af6f 100644
--- a/gcc/config/mips/mips.md
+++ b/gcc/config/mips/mips.md
@@ -162,7 +162,6 @@
   [(TLS_GET_TP_REGNUM		3)
    (GET_FCSR_REGNUM		2)
    (SET_FCSR_REGNUM		4)
-   (MIPS16_T_REGNUM		24)
    (PIC_FUNCTION_ADDR_REGNUM	25)
    (RETURN_ADDR_REGNUM		31)
    (CPRESTORE_SLOT_REGNUM	76)
@@ -6389,68 +6388,57 @@
   if (!arith_operand (operands[0], SImode))
     operands[0] = force_reg (SImode, operands[0]);
 
-  operands[2] = GEN_INT (INTVAL (operands[2]) + 1);
-
+  emit_cmp_and_jump_insns (operands[0], operands[2], GTU,
+			   NULL_RTX, SImode, 1, operands[4]);
   emit_jump_insn (PMODE_INSN (gen_casesi_internal_mips16,
-			      (operands[0], operands[2],
-			       operands[3], operands[4])));
-
+			      (operands[0], operands[3])));
   DONE;
 })
 
 (define_insn "casesi_internal_mips16_<mode>"
   [(set (pc)
-     (if_then_else
-       (ltu (match_operand:SI 0 "register_operand" "d")
-	    (match_operand:SI 1 "arith_operand" "dI"))
-       (unspec:P
-        [(match_dup 0)
-	 (label_ref (match_operand 2 "" ""))]
-	UNSPEC_CASESI_DISPATCH)
-       (label_ref (match_operand 3 "" ""))))
-   (clobber (match_scratch:P 4 "=d"))
-   (clobber (match_scratch:P 5 "=d"))
-   (clobber (reg:SI MIPS16_T_REGNUM))]
+	(unspec:P [(match_operand:SI 0 "register_operand" "d")
+		   (label_ref (match_operand 1 "" ""))]
+	 UNSPEC_CASESI_DISPATCH))
+   (clobber (match_scratch:P 2 "=d"))
+   (clobber (match_scratch:P 3 "=d"))]
   "TARGET_MIPS16_SHORT_JUMP_TABLES"
 {
-  rtx diff_vec = PATTERN (NEXT_INSN (as_a <rtx_insn *> (operands[2])));
+  rtx diff_vec = PATTERN (NEXT_INSN (as_a <rtx_insn *> (operands[1])));
 
   gcc_assert (GET_CODE (diff_vec) == ADDR_DIFF_VEC);
-  
-  output_asm_insn ("sltu\t%0, %1", operands);
-  output_asm_insn ("bteqz\t%3", operands);
-  
+
   switch (GET_MODE (diff_vec))
     {
     case HImode:
-      output_asm_insn ("sll\t%5, %0, 1", operands);
-      output_asm_insn ("<d>la\t%4, %2", operands);
-      output_asm_insn ("<d>addu\t%5, %4, %5", operands);
-      output_asm_insn ("lh\t%5, 0(%5)", operands);
+      output_asm_insn ("sll\t%3,%0,1", operands);
+      output_asm_insn ("<d>la\t%2,%1", operands);
+      output_asm_insn ("<d>addu\t%3,%2,%3", operands);
+      output_asm_insn ("lh\t%3,0(%3)", operands);
       break;
 
     case SImode:
-      output_asm_insn ("sll\t%5, %0, 2", operands);
-      output_asm_insn ("<d>la\t%4, %2", operands);
-      output_asm_insn ("<d>addu\t%5, %4, %5", operands);
-      output_asm_insn ("lw\t%5, 0(%5)", operands);
+      output_asm_insn ("sll\t%3,%0,2", operands);
+      output_asm_insn ("<d>la\t%2,%1", operands);
+      output_asm_insn ("<d>addu\t%3,%2,%3", operands);
+      output_asm_insn ("lw\t%3,0(%3)", operands);
       break;
 
     default:
       gcc_unreachable ();
     }
 
-  output_asm_insn ("<d>addu\t%4, %4, %5", operands);
+  output_asm_insn ("<d>addu\t%2,%2,%3", operands);
 
   if (GENERATE_MIPS16E)
-    return "jrc\t%4";
+    return "jrc\t%2";
   else
-    return "jr\t%4";
+    return "jr\t%2";
 }
   [(set (attr "insn_count")
 	(if_then_else (match_test "GENERATE_MIPS16E")
-		      (const_string "10")
-		      (const_string "11")))])
+		      (const_string "6")
+		      (const_string "7")))])
 
 ;; For TARGET_USE_GOT, we save the gp in the jmp_buf as well.
 ;; While it is possible to either pull it off the stack (in the
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a0c522e..dc82af0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2017-06-14  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* gcc.target/mips/data-sym-jump.c: Adjust for whitespace changes.
+	* gcc.target/mips/pr51513-1.c: New test.
+	* gcc.target/mips/pr51513-2.c: New test.
+
 2017-06-14  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/81083
diff --git a/gcc/testsuite/gcc.target/mips/data-sym-jump.c b/gcc/testsuite/gcc.target/mips/data-sym-jump.c
index c3ba294..ae48c0b 100644
--- a/gcc/testsuite/gcc.target/mips/data-sym-jump.c
+++ b/gcc/testsuite/gcc.target/mips/data-sym-jump.c
@@ -25,7 +25,7 @@ frob (int i)
 
 /* Expect assembly like:
 
-	la	$2, $L4
+	la	$2,$L4
 						# Anything goes here.
 	.type	__jump_frob_4, @object		# Symbol # must match label.
 __jump_frob_4:					# The symbol must match.
@@ -47,4 +47,4 @@ __jend_frob_4:					# The symbol must match.
 
    that is `__jump_*'/`__jend_*' symbols inserted around a jump table.  */
 
-/* { dg-final { scan-assembler "\tla\t\\\$\[0-9\]+, (.L(\[0-9\]+))\n.*\t\\.type\t(__jump_frob_\\2), @object\n\\3:\n\\1:\n(?:\t\\.(?:half|word)\t.L\[0-9\]+-\\1\n)\{11\}\t\\.type\t(__jend_frob_\\2), @function\n\\4:\n\t\\.insn\n" } } */
+/* { dg-final { scan-assembler "\tla\t\\\$\[0-9\]+,(.L(\[0-9\]+))\n.*\t\\.type\t(__jump_frob_\\2), @object\n\\3:\n\\1:\n(?:\t\\.(?:half|word)\t.L\[0-9\]+-\\1\n)\{11\}\t\\.type\t(__jend_frob_\\2), @function\n\\4:\n\t\\.insn\n" } } */
diff --git a/gcc/testsuite/gcc.target/mips/pr51513-1.c b/gcc/testsuite/gcc.target/mips/pr51513-1.c
new file mode 100644
index 0000000..b5e0d69
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/pr51513-1.c
@@ -0,0 +1,48 @@
+/* { dg-do compile } */
+/* { dg-options "-mips16 -mcode-readable=yes" } */
+
+/* PR tree-optimization/51513 verification variant for MIPS16, #1.  */
+
+int __attribute__ ((weak))
+frob (int i)
+{
+  switch (i)
+    {
+    case -5:
+      return -2;
+    case -3:
+      return -1;
+    case 0:
+      return 0;
+    case 3:
+      return 1;
+    case 5:
+      break;
+    default:
+      __builtin_unreachable ();
+    }
+  return i;
+}
+
+/* Without the fix for PR tree-optimization/51513 truncated code
+   would be emitted for `frob', like:
+
+	.text
+	.align	2
+	.weak	frob
+	.set	mips16
+	.set	nomicromips
+	.ent	frob
+	.type	frob, @function
+frob:
+	.frame	$sp,0,$31		# vars= 0, regs= 0/0, args= 0, gp= 0
+	.mask	0x00000000,0
+	.fmask	0x00000000,0
+	addiu	$2,$4,5
+	.end	frob
+	.size	frob, .-frob
+
+  meaning `frob' will have no chance to return, let alone produce
+  the result expected.  */
+
+/* { dg-final { scan-assembler "\tjrc?\t\\\$31\n" } } */
diff --git a/gcc/testsuite/gcc.target/mips/pr51513-2.c b/gcc/testsuite/gcc.target/mips/pr51513-2.c
new file mode 100644
index 0000000..b921904
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/pr51513-2.c
@@ -0,0 +1,56 @@
+/* { dg-do run } */
+/* { dg-options "-mips16 -mcode-readable=yes" } */
+
+/* PR tree-optimization/51513 verification variant for MIPS16, #2.  */
+
+int __attribute__ ((weak))
+frob (int i)
+{
+  switch (i)
+    {
+    case -5:
+      return -2;
+    case -3:
+      return -1;
+    case 0:
+      return 0;
+    case 3:
+      return 1;
+    case 5:
+      break;
+    default:
+      __builtin_unreachable ();
+    }
+  return i;
+}
+
+int
+main (void)
+{
+  return !(frob (-5) == -2
+	   & frob (-3) == -1
+	   & frob (0) == 0
+	   & frob (3) == 1
+	   & frob (5) == 5);
+}
+
+/* Without the fix for PR tree-optimization/51513 truncated code
+   would be emitted for `frob', like:
+
+	.text
+	.align	2
+	.weak	frob
+	.set	mips16
+	.set	nomicromips
+	.ent	frob
+	.type	frob, @function
+frob:
+	.frame	$sp,0,$31		# vars= 0, regs= 0/0, args= 0, gp= 0
+	.mask	0x00000000,0
+	.fmask	0x00000000,0
+	addiu	$2,$4,5
+	.end	frob
+	.size	frob, .-frob
+
+  meaning `frob' will have no chance to return, let alone produce
+  the result expected.  */