Handle casesi dispatch tablejumps in create_trace_edges (as well)

* rtlanal.c (tablejump_casesi_pattern): New function, to
	determine if a tablejump insn is a casesi dispatcher. Extracted
	from patch_jump_insn.
	* rtl.h (tablejump_casesi_pattern): Declare.
	* cfgrtl.c (patch_jump_insn): Use it.
	* dwarf2cfi.c (create_trace_edges): Use it.

testsuite/

	* gnat.dg/casesi.ad[bs], test_casesi.adb: New test.

From-SVN: r274377

gcc/ChangeLog

@@ -1,3 +1,12 @@
+2019-08-13  Olivier Hainque  <hainque@adacore.com>
+
+	* rtlanal.c (tablejump_casesi_pattern): New function, to
+	determine if a tablejump insn is a casesi dispatcher. Extracted
+	from patch_jump_insn.
+	* rtl.h (tablejump_casesi_pattern): Declare.
+	* cfgrtl.c (patch_jump_insn): Use it.
+	* dwarf2cfi.c (create_trace_edges): Use it.
+
 2019-08-13  Wilco Dijkstra  <wdijkstr@arm.com>  
 
 	PR target/81800

gcc/cfgrtl.c

@@ -1214,10 +1214,7 @@ patch_jump_insn (rtx_insn *insn, rtx_insn *old_label, basic_block new_bb)
 	  }
 
       /* Handle casesi dispatch insns.  */
-      if ((tmp = single_set (insn)) != NULL
-	  && SET_DEST (tmp) == pc_rtx
-	  && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
-	  && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF
+      if ((tmp = tablejump_casesi_pattern (insn)) != NULL_RTX
 	  && label_ref_label (XEXP (SET_SRC (tmp), 2)) == old_label)
 	{
 	  XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode,

gcc/dwarf2cfi.c

@@ -2445,6 +2445,13 @@ create_trace_edges (rtx_insn *insn)
 	      rtx_insn *lab = as_a <rtx_insn *> (XEXP (RTVEC_ELT (vec, i), 0));
 	      maybe_record_trace_start (lab, insn);
 	    }
+
+	  /* Handle casesi dispatch insns.  */
+	  if ((tmp = tablejump_casesi_pattern (insn)) != NULL_RTX)
+	    {
+	      rtx_insn * lab = label_ref_label (XEXP (SET_SRC (tmp), 2));
+	      maybe_record_trace_start (lab, insn);
+	    }
 	}
       else if (computed_jump_p (insn))
 	{

gcc/rtl.h

@@ -2945,6 +2945,7 @@ extern rtvec shallow_copy_rtvec (rtvec);
 extern bool shared_const_p (const_rtx);
 extern rtx copy_rtx (rtx);
 extern enum rtx_code classify_insn (rtx);
+extern rtx tablejump_casesi_pattern (const rtx_insn *insn);
 extern void dump_rtx_statistics (void);
 
 /* In emit-rtl.c */

gcc/rtlanal.c

@@ -3272,6 +3272,23 @@ tablejump_p (const rtx_insn *insn, rtx_insn **labelp,
   return true;
 }
 
+/* For INSN known to satisfy tablejump_p, determine if it actually is a
+   CASESI.  Return the insn pattern if so, NULL_RTX otherwise.  */
+
+rtx
+tablejump_casesi_pattern (const rtx_insn *insn)
+{
+  rtx tmp;
+
+  if ((tmp = single_set (insn)) != NULL
+      && SET_DEST (tmp) == pc_rtx
+      && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
+      && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF)
+    return tmp;
+
+  return NULL_RTX;
+}
+
 /* A subroutine of computed_jump_p, return 1 if X contains a REG or MEM or
    constant that is not in the constant pool and not in the condition
    of an IF_THEN_ELSE.  */

gcc/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2019-08-13  Olivier Hainque  <hainque@adacore.com>
+
+	* gnat.dg/casesi.ad[bs], test_casesi.adb: New test.
+
 2019-08-13  Wilco Dijkstra  <wdijkstr@arm.com>  
 
 	PR target/81800

gcc/testsuite/gnat.dg/casesi.adb

@@ -0,0 +1,28 @@
+with Ada.Assertions;
+package body Casesi is
+
+  function Process (X : Natural) return String is
+  begin
+     case X is
+        when 0 => raise Ada.Assertions.Assertion_Error;
+        when 1 => raise Ada.Assertions.Assertion_Error;
+        when 2 => return (1 .. 4 => 'T');
+        when 3 => return (2 .. 8 => 'T');
+        when 4 => return "hello";
+        when others => return (1 .. 0 => <>);
+     end case;
+  end;
+
+  procedure Try (X : Natural) is
+  begin
+     declare
+        Code : String := Process (X);
+     begin
+        if X < 2 then
+           raise Program_Error;
+        end if;
+     end;
+  exception
+     when Ada.Assertions.Assertion_Error => null;
+  end;
+end;

gcc/testsuite/gnat.dg/casesi.ads

@@ -0,0 +1,4 @@
+
+package Casesi is
+  procedure Try (X : Natural);
+end;

gcc/testsuite/gnat.dg/test_casesi.adb

@@ -0,0 +1,12 @@
+-- { dg-do run }
+-- { dg-options "-O2" }
+
+with Casesi;
+procedure Test_Casesi is
+begin
+  Casesi.Try (1);
+  Casesi.Try (2);
+  Casesi.Try (3);
+end;
+
+