Make lra use per-alternative earlyclobber info

lra_insn_reg and lra_operand_data have both a bitmask of earlyclobber
alternatives and an overall boolean.  The danger is that we then test
the overall boolean when really we should be testing for a particular
alternative.  This patch gets rid of the boolean and tests the mask
against zero when we really do need to test "any alternative might
be earlyclobber".  (I think the only instance of that is the
LRA_UNKNOWN_ALT handling in lra-lives.c:reg_early_clobber_p.)

This is needed (and tested) by an upcoming SVE patch.

2019-07-31  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* lra-int.h (lra_operand_data): Remove early_clobber field.
	(lra_insn_reg): Likewise.
	* lra.c (debug_operand_data): Update accordingly.
	(setup_operand_alternative): Likewise.
	(new_insn_reg): Likewise.  Remove early_clobber parameter.
	(collect_non_operand_hard_regs): Update call accordingly.
	Don't assign to lra_insn_reg::early_clobber.
	(add_regs_to_insn_regno_info): Remove early_clobber parameter
	and update calls to new_insn_reg.
	(lra_update_insn_regno_info): Update calls accordingly.
	* lra-constraints.c (update_and_check_small_class_inputs): Take the
	alternative number as a parameter and test whether the operand
	is earlyclobbered in that particular alternative.
	(process_alt_operands): Update call accordingly.  Use per-alternative
	checks for earyclobber here too.
	* lra-lives.c (reg_early_clobber_p): Check early_clobber_alts
	against zero for IRA_UNKNOWN_ALT.

From-SVN: r273921

1 files changed, 12 insertions, 8 deletions

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index bd9f85d..f258407 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -1866,11 +1866,12 @@ prohibited_class_reg_set_mode_p (enum reg_class rclass,
    alternative.  */
 static unsigned int curr_small_class_check = 0;
 
-/* Update number of used inputs of class OP_CLASS for operand NOP.
-   Return true if we have more such class operands than the number of
-   available regs.  */
+/* Update number of used inputs of class OP_CLASS for operand NOP
+   of alternative NALT.  Return true if we have more such class operands
+   than the number of available regs.  */
 static bool
-update_and_check_small_class_inputs (int nop, enum reg_class op_class)
+update_and_check_small_class_inputs (int nop, int nalt,
+				     enum reg_class op_class)
 {
   static unsigned int small_class_check[LIM_REG_CLASSES];
   static int small_class_input_nums[LIM_REG_CLASSES];
@@ -1881,7 +1882,7 @@ update_and_check_small_class_inputs (int nop, enum reg_class op_class)
       && hard_reg_set_intersect_p (reg_class_contents[op_class],
 				   ira_no_alloc_regs)
       && (curr_static_id->operand[nop].type != OP_OUT
-	  || curr_static_id->operand[nop].early_clobber))
+	  || TEST_BIT (curr_static_id->operand[nop].early_clobber_alts, nalt)))
     {
       if (small_class_check[op_class] == curr_small_class_check)
 	small_class_input_nums[op_class]++;
@@ -2150,7 +2151,8 @@ process_alt_operands (int only_alternative)
 			/* We should reject matching of an early
 			   clobber operand if the matching operand is
 			   not dying in the insn.  */
-			if (! curr_static_id->operand[m].early_clobber
+			if (!TEST_BIT (curr_static_id->operand[m]
+				       .early_clobber_alts, nalt)
 			    || operand_reg[nop] == NULL_RTX
 			    || (find_regno_note (curr_insn, REG_DEAD,
 						 REGNO (op))
@@ -2234,7 +2236,8 @@ process_alt_operands (int only_alternative)
 			   it results in less hard regs required for
 			   the insn than a non-matching earlyclobber
 			   alternative.  */
-			if (curr_static_id->operand[m].early_clobber)
+			if (TEST_BIT (curr_static_id->operand[m]
+				      .early_clobber_alts, nalt))
 			  {
 			    if (lra_dump_file != NULL)
 			      fprintf
@@ -2875,7 +2878,8 @@ process_alt_operands (int only_alternative)
               goto fail;
             }
 
-	  if (update_and_check_small_class_inputs (nop, this_alternative))
+	  if (update_and_check_small_class_inputs (nop, nalt,
+						   this_alternative))
 	    {
 	      if (lra_dump_file != NULL)
 		fprintf (lra_dump_file,