===================================================================
@@ -417,6 +417,16 @@ operand_to_remat (rtx_insn *insn)
return -1;
found_reg = reg;
}
+ /* IRA calculates conflicts separately for subregs of two words
+ pseudo. Even if the pseudo lives, e.g. one its subreg can be
+ used lately, another subreg hard register can be already used
+ for something else. In such case, it is not safe to
+ rematerialize the insn. */
+ else if (reg->type == OP_IN && reg->subreg_p
+ && reg->regno >= FIRST_PSEUDO_REGISTER
+ && (GET_MODE_SIZE (PSEUDO_REGNO_MODE (reg->regno))
+ == 2 * UNITS_PER_WORD))
+ return -1;
if (found_reg == NULL)
return -1;
if (found_reg->regno < FIRST_PSEUDO_REGISTER)
===================================================================
@@ -0,0 +1,51 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-require-effective-target ia32 } */
+int a, b, c, d, e[2], f, l, m, n, o;
+long long g = 1, j;
+static unsigned int h;
+static int i, k;
+
+void
+fn1 (long long p)
+{
+ int q = p;
+ f = 1 ^ e[f ^ (q & 1)];
+}
+
+static void
+fn2 (long long p)
+{
+ f = 1 ^ e[(f ^ 1) & 1];
+ fn1 (p >> 1 & 1);
+ fn1 (p >> 32 & 1);
+}
+
+void
+fn3 (int p)
+{
+ g |= j = p;
+}
+
+int
+main ()
+{
+ e[0] = 1;
+ char p = l;
+ h = --g;
+ i = o = c;
+ m = d ? 1 / d : 0;
+ fn3 (l || 0);
+ b = a;
+ n = j++;
+ k--;
+ fn2 (g);
+ fn2 (h);
+ fn2 (i);
+
+ if (k + f)
+ __builtin_abort ();
+
+ return 0;
+}
+
The following patch fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66424 The patch was tested and bootstrapped on x86/x86-64. Committed as rev. 226053. 2015-07-21 Vladimir Makarov <vmakarov@redhat.com> PR ipa/66424. * lra-remat.c (operand_to_remat): Prevent using insns with input subregs processed separately by IRA. 2015-07-21 Vladimir Makarov <vmakarov@redhat.com> PR ipa/66424. * gcc.target/i386/pr66424.c: New.