patch for PR71374

patch for PR71374

[Vladimir Makarov]

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The following patch solves

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71374

The patch was successfully bootstrapped and tested on x86-64.

Committed as rev. 244991.



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Index: ChangeLog
===================================================================
--- ChangeLog	(revision 244990)
+++ ChangeLog	(working copy)
@@ -1,5 +1,11 @@
 2017-01-27  Vladimir Makarov  <vmakarov@redhat.com>
 
+	PR tree-optimization/71374
+	* lra-constraints.c (check_conflict_input_operands): New.
+	(match_reload): Use it.
+
+2017-01-27  Vladimir Makarov  <vmakarov@redhat.com>
+
 	PR target/79131
 	* lra-assigns.c (find_hard_regno_for_1): Take endianess for into
 	account to calculate conflict_set.
Index: testsuite/ChangeLog
===================================================================
--- testsuite/ChangeLog	(revision 244990)
+++ testsuite/ChangeLog	(working copy)
@@ -1,3 +1,8 @@
+2017-01-27  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR tree-optimization/71374
+	* testsuite/gcc.target/i386/pr71374.c: New.
+
 2017-01-27  Martin Sebor  <msebor@redhat.com>
 
 	PR c++/71290
Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 244942)
+++ lra-constraints.c	(working copy)
@@ -878,6 +878,29 @@ regno_val_use_in (unsigned int regno, rt
   return NULL_RTX;
 }
 
+/* Return true if all current insn non-output operands except INS (it
+   has a negaitve end marker) do not use pseudos with the same value
+   as REGNO.  */
+static bool
+check_conflict_input_operands (int regno, signed char *ins)
+{
+  int in;
+  int n_operands = curr_static_id->n_operands;
+
+  for (int nop = 0; nop < n_operands; nop++)
+    if (! curr_static_id->operand[nop].is_operator
+	&& curr_static_id->operand[nop].type != OP_OUT)
+      {
+	for (int i = 0; (in = ins[i]) >= 0; i++)
+	  if (in == nop)
+	    break;
+	if (in < 0
+	    && regno_val_use_in (regno, *curr_id->operand_loc[nop]) != NULL_RTX)
+	  return false;
+      }
+  return true;
+}
+
 /* Generate reloads for matching OUT and INS (array of input operand
    numbers with end marker -1) with reg class GOAL_CLASS, considering
    output operands OUTS (similar array to INS) needing to be in different
@@ -917,7 +940,9 @@ match_reload (signed char out, signed ch
 	     pseudos as reload pseudos can die although original
 	     pseudos still live where reload pseudos dies.  */
 	  if (REG_P (in_rtx) && (int) REGNO (in_rtx) < lra_new_regno_start
-	      && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx)))
+	      && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx))
+	      && (!early_clobber_p
+		  || check_conflict_input_operands(REGNO (in_rtx), ins)))
 	    lra_assign_reg_val (REGNO (in_rtx), REGNO (reg));
 	}
       else
@@ -947,7 +972,10 @@ match_reload (signed char out, signed ch
 		  && (int) REGNO (subreg_reg) < lra_new_regno_start
 		  && GET_MODE (subreg_reg) == outmode
 		  && SUBREG_BYTE (in_rtx) == SUBREG_BYTE (new_in_reg)
-		  && find_regno_note (curr_insn, REG_DEAD, REGNO (subreg_reg)))
+		  && find_regno_note (curr_insn, REG_DEAD, REGNO (subreg_reg))
+		  && (! early_clobber_p
+		      || check_conflict_input_operands (REGNO (subreg_reg),
+							ins)))
 		lra_assign_reg_val (REGNO (subreg_reg), REGNO (reg));
 	    }
 	}
@@ -1002,6 +1030,8 @@ match_reload (signed char out, signed ch
 	= (! early_clobber_p && ins[1] < 0 && REG_P (in_rtx)
 	   && (int) REGNO (in_rtx) < lra_new_regno_start
 	   && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx))
+	   && (! early_clobber_p
+	       || check_conflict_input_operands (REGNO (in_rtx), ins))
 	   && (out < 0
 	       || regno_val_use_in (REGNO (in_rtx), out_rtx) == NULL_RTX)
 	   && !out_conflict
Index: testsuite/gcc.target/i386/pr71374.c
===================================================================
--- testsuite/gcc.target/i386/pr71374.c	(revision 0)
+++ testsuite/gcc.target/i386/pr71374.c	(working copy)
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+int a, b, c;
+void
+foo (void *x, void *y)
+{
+  __asm__ ("": "=&c" (a), "=&D" (b), "=&S" (c): "r" (y), "2" (y));
+}