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.
Index: ChangeLog
===================================================================
--- ChangeLog (revision 244990)
+++ ChangeLog (working copy)
@@ -1,5 +1,11 @@
2017-01-27 Vladimir Makarov <vmaka...@redhat.com>
+ PR tree-optimization/71374
+ * lra-constraints.c (check_conflict_input_operands): New.
+ (match_reload): Use it.
+
+2017-01-27 Vladimir Makarov <vmaka...@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 <vmaka...@redhat.com>
+
+ PR tree-optimization/71374
+ * testsuite/gcc.target/i386/pr71374.c: New.
+
2017-01-27 Martin Sebor <mse...@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));
+}
