From: Pengxuan Zheng <quic_pzheng@quicinc.com>
Date: Fri, 16 May 2025 00:52:29 +0000 (-0700)
Subject: aarch64: Fix an oversight in aarch64_evpc_reencode
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d77c3bc1c35e3032b91648dbef4e0ef1f6020017;p=thirdparty%2Fgcc.git

aarch64: Fix an oversight in aarch64_evpc_reencode

Some fields (e.g., zero_op0_p and zero_op1_p) of the struct "newd" may be left
uninitialized in aarch64_evpc_reencode. This can cause reading of uninitialized
data. I found this oversight when testing my patches on and/fmov
optimizations. This patch fixes the bug by zero initializing the struct.

Pushed as obvious after bootstrap/test on aarch64-linux-gnu.

gcc/ChangeLog:

	* config/aarch64/aarch64.cc (aarch64_evpc_reencode): Zero initialize
	newd.
---

diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 901aa6ea68a..f5552e4b86c 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -26277,7 +26277,7 @@ 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.  */