Hi!
In PR65321 I've added lower_subreg call on the last argument of ASHIFT, but
as the following testcase shows, use_narrower_mode_test has not been updated
correspondingly to verify lower_subreg will actually work.
On the testcase validate_subreg actually is happy about it, but because op1
is already a (subreg:SI (reg:V32HI ) 48) and simplify_subreg fails, it fails
anyway.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?
2018-06-20 Jakub Jelinek <ja...@redhat.com>
PR debug/86194
* var-tracking.c (use_narrower_mode_test): Check if shift amount can
be narrowed.
* gcc.target/i386/pr86194.c: New test.
--- gcc/var-tracking.c.jj 2018-06-13 10:05:53.146127176 +0200
+++ gcc/var-tracking.c 2018-06-20 11:06:29.045456044 +0200
@@ -964,6 +964,24 @@ use_narrower_mode_test (rtx x, const_rtx
case MULT:
break;
case ASHIFT:
+ if (GET_MODE (XEXP (x, 1)) != VOIDmode)
+ {
+ enum machine_mode mode = GET_MODE (subreg);
+ rtx op1 = XEXP (x, 1);
+ enum machine_mode op1_mode = GET_MODE (op1);
+ if (GET_MODE_PRECISION (as_a <scalar_int_mode> (mode))
+ < GET_MODE_PRECISION (as_a <scalar_int_mode> (op1_mode)))
+ {
+ poly_uint64 byte = subreg_lowpart_offset (mode, op1_mode);
+ if (GET_CODE (op1) == SUBREG || GET_CODE (op1) == CONCAT)
+ {
+ if (!simplify_subreg (mode, op1, op1_mode, byte))
+ return false;
+ }
+ else if (!validate_subreg (mode, op1_mode, op1, byte))
+ return false;
+ }
+ }
iter.substitute (XEXP (x, 0));
break;
default:
--- gcc/testsuite/gcc.target/i386/pr86194.c.jj 2018-06-20 11:12:46.801031294
+0200
+++ gcc/testsuite/gcc.target/i386/pr86194.c 2018-06-20 11:08:56.508680601
+0200
@@ -0,0 +1,24 @@
+/* PR debug/86194 */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O -g -mavx512bw" } */
+
+typedef unsigned U __attribute__ ((vector_size (64)));
+typedef unsigned long V __attribute__ ((vector_size (64)));
+typedef unsigned __int128 W __attribute__ ((vector_size (64)));
+
+U u;
+
+W
+bar (W w)
+{
+ U k = u;
+ w <<= (W)(U) { 5, 3, 3, 0, 7, 3, 1, 3, k[7] };
+ k += (U) { -(char)w[3] } != k;
+ return (W)k + w;
+}
+
+void
+foo (void)
+{
+ u = (U){ bar ((W)(V) { 0, ~0, 0, 0, 0, 0, ~0 })[0] };
+}
Jakub
