The following patch fixes
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64110
The patch was successfully tested and bootstrapped on x86/x86-64.
Committed as rev. 218688.
2014-12-12 Vladimir Makarov <vmaka...@redhat.com>
PR target/64110
* lra-constraints.c (process_alt_operands): Refuse alternative
when reload pseudo of given class can not hold value of given
mode.
2014-12-12 Vladimir Makarov <vmaka...@redhat.com>
PR target/64110
* gcc.target/i386/pr64110.c: New.
Index: lra-constraints.c
===================================================================
--- lra-constraints.c (revision 218685)
+++ lra-constraints.c (working copy)
@@ -2267,6 +2267,29 @@ process_alt_operands (int only_alternati
goto fail;
}
+ /* Alternative loses if it required class pseudo can not
+ hold value of required mode. Such insns can be
+ described by insn definitions with mode iterators.
+ Don't use ira_prohibited_class_mode_regs here as it
+ is common practice for constraints to use a class
+ which does not have actually enough regs to hold the
+ value (e.g. x86 AREG for mode requiring more one
+ general reg). */
+ if (GET_MODE (*curr_id->operand_loc[nop]) != VOIDmode
+ && ! hard_reg_set_empty_p (this_alternative_set)
+ && ! HARD_REGNO_MODE_OK (ira_class_hard_regs
+ [this_alternative][0],
+ GET_MODE
(*curr_id->operand_loc[nop])))
+ {
+ if (lra_dump_file != NULL)
+ fprintf
+ (lra_dump_file,
+ " alt=%d: reload pseudo for op %d "
+ " can not hold the mode value -- refuse\n",
+ nalt, nop);
+ goto fail;
+ }
+
/* Check strong discouragement of reload of non-constant
into class THIS_ALTERNATIVE. */
if (! CONSTANT_P (op) && ! no_regs_p
Index: testsuite/gcc.target/i386/pr64110.c
===================================================================
--- testsuite/gcc.target/i386/pr64110.c (revision 0)
+++ testsuite/gcc.target/i386/pr64110.c (working copy)
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=core-avx2" } */
+
+int foo (void);
+int a;
+short *b;
+
+void
+bar (short x)
+{
+ while (a--)
+ {
+ int i, j = foo ();
+ for (i = 0; i < j; ++i)
+ *b++ = x;
+ }
+}
