re PR middle-end/53590 (compiler fails to generate SIMD instruction for FP division)

	PR middle-end/53590
	* common.opt (-fdelete-dead-exceptions): New switch.
	* doc/invoke.texi (Code Gen Options): Document it.
	* cse.c (count_reg_usage) <CALL_INSN>: Use !insn_nothrow_p in lieu of
	insn_could_throw_p predicate.  Do not skip an insn that could throw
	if dead exceptions can be deleted.
	(insn_live_p): Likewise, do not return true in that case.
	* dce.c (can_alter_cfg): New flag.
	(deletable_insn_p): Do not return false for an insn that can throw if
	the CFG can be altered and dead exceptions can be deleted.
	(init_dce): Set can_alter_cfg to false for fast DCE, true otherwise.
	* dse.c (scan_insn): Use !insn_nothrow_p in lieu of insn_could_throw_
	predicate. Do not preserve an insn that could throw if dead exceptions
	can be deleted.
	* function.h (struct function): Add can_delete_dead_exceptions flag.
	* function.c (allocate_struct_function): Set it.
	* lto-streamer-in.c (input_struct_function_base): Stream it.
	* lto-streamer-out.c (input_struct_function_base): Likewise.
	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Do not mark a
	statement that could throw as necessary if dead exceptions can be
	deleted.
ada/
	* gcc-interface/misc.c (gnat_init_options_struct): Set
	opts->x_flag_delete_dead_exceptions to 1.

From-SVN: r188651

1 files changed, 4 insertions, 4 deletions

diff --git a/gcc/cse.c b/gcc/cse.c
index 783c932..9d5e32e 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -599,7 +599,6 @@ static void invalidate_from_clobbers (rtx);
 static void invalidate_from_sets_and_clobbers (rtx);
 static rtx cse_process_notes (rtx, rtx, bool *);
 static void cse_extended_basic_block (struct cse_basic_block_data *);
-static void count_reg_usage (rtx, int *, rtx, int);
 static int check_for_label_ref (rtx *, void *);
 extern void dump_class (struct table_elt*);
 static void get_cse_reg_info_1 (unsigned int regno);
@@ -6692,10 +6691,11 @@ count_reg_usage (rtx x, int *counts, rtx dest, int incr)
     case CALL_INSN:
     case INSN:
     case JUMP_INSN:
-      /* We expect dest to be NULL_RTX here.  If the insn may trap,
+      /* We expect dest to be NULL_RTX here.  If the insn may throw,
 	 or if it cannot be deleted due to side-effects, mark this fact
 	 by setting DEST to pc_rtx.  */
-      if (insn_could_throw_p (x) || side_effects_p (PATTERN (x)))
+      if ((!cfun->can_delete_dead_exceptions && !insn_nothrow_p (x))
+	  || side_effects_p (PATTERN (x)))
 	dest = pc_rtx;
       if (code == CALL_INSN)
 	count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, dest, incr);
@@ -6800,7 +6800,7 @@ static bool
 insn_live_p (rtx insn, int *counts)
 {
   int i;
-  if (insn_could_throw_p (insn))
+  if (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn))
     return true;
   else if (GET_CODE (PATTERN (insn)) == SET)
     return set_live_p (PATTERN (insn), insn, counts);