aarch64: Carry over zeroness in aarch64_evpc_reencode

There was a bug in aarch64_evpc_reencode which could leave zero_op0_p and
zero_op1_p of the struct "newd" uninitialized.  r16-701-gd77c3bc1c35e303 fixed
the issue by zero initializing "newd."  This patch provides an alternative fix
as suggested by Richard Sandiford based on the fact that the zeroness is
preserved by aarch64_evpc_reencode.

gcc/ChangeLog:

	* config/aarch64/aarch64.cc (aarch64_evpc_reencode): Copy zero_op0_p and
	zero_op1_p from d to newd.

Signed-off-by: Pengxuan Zheng <quic_pzheng@quicinc.com>

diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 1da615c8955a4b7b4c5434f4ae67c517361a96aa..2b837ec8e6736e5c879f445da34f8ab5401c18aa 100644 (file)
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -26327,7 +26327,7 @@ aarch64_evpc_trn (struct expand_vec_perm_d *d)
 static bool
 aarch64_evpc_reencode (struct expand_vec_perm_d *d)
 {
-  expand_vec_perm_d newd = {};
+  expand_vec_perm_d newd;
 
   /* The subregs that we'd create are not supported for big-endian SVE;
      see aarch64_modes_compatible_p for details.  */
@@ -26353,6 +26353,8 @@ aarch64_evpc_reencode (struct expand_vec_perm_d *d)
   newd.op1 = d->op1 ? gen_lowpart (new_mode, d->op1) : NULL;
   newd.testing_p = d->testing_p;
   newd.one_vector_p = d->one_vector_p;
+  newd.zero_op0_p = d->zero_op0_p;
+  newd.zero_op1_p = d->zero_op1_p;
 
   newd.perm.new_vector (newpermindices.encoding (), newd.one_vector_p ? 1 : 2,
                        newpermindices.nelts_per_input ());