toolchain/gcc/patches/9.2.0/100-Fix_uninitialised_use_in_mips_split_move.patch

   1 From d57faea9337ad595d005687247c3322252f70ba1 Mon Sep 17 00:00:00 2001
   2 From: rsandifo <rsandifo@138bc75d-0d04-0410-961f-82ee72b054a4>
   3 Date: Sun, 7 Jul 2019 09:49:14 +0000
   4 Subject: [PATCH] Fix uninitialised use in mips_split_move
   5
   6 While testing the fix for PR91068, I hit an rtl checking failure
   7 while building newlib.  mips_split_move was decomposing an address that
   8 happened to be symbolic and then tried to access the REGNO of the base
   9 register field, which wasn't initialised but which by chance pointed to
  10 valid memory.
  11
  12 2019-07-07  Richard Sandiford  <richard.sandiford@arm.com>
  13
  14 gcc/
  15         * config/mips/mips.c (mips_split_move): Zero-initialize addr
  16         and check whether addr.reg is nonnull before using it.
  17
  18
  19 git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@273174 138bc75d-0d04-0410-961f-82ee72b054a4
  20 ---
  21  gcc/ChangeLog          | 5 +++++
  22  gcc/config/mips/mips.c | 4 ++--
  23  2 files changed, 7 insertions(+), 2 deletions(-)
  24
  25 --- a/gcc/ChangeLog
  26 +++ b/gcc/ChangeLog
  27 @@ -1,3 +1,8 @@
  28 +2019-07-07  Richard Sandiford  <richard.sandiford@arm.com>
  29 +
  30 +       * config/mips/mips.c (mips_split_move): Zero-initialize addr
  31 +       and check whether addr.reg is nonnull before using it.
  32 +
  33  2019-08-12  Release Manager
  34
  35         * GCC 9.2.0 released.
  36 --- a/gcc/config/mips/mips.c
  37 +++ b/gcc/config/mips/mips.c
  38 @@ -4849,7 +4849,7 @@ mips_split_move (rtx dest, rtx src, enum
  39       can forward SRC for DEST.  This is most useful if the next insn is a
  40       simple store.   */
  41    rtx_insn *insn = (rtx_insn *)insn_;
  42 -  struct mips_address_info addr;
  43 +  struct mips_address_info addr = {};
  44    if (insn)
  45      {
  46        rtx_insn *next = next_nonnote_nondebug_insn_bb (insn);
  47 @@ -4862,7 +4862,7 @@ mips_split_move (rtx dest, rtx src, enum
  48                 {
  49                   rtx tmp = XEXP (src, 0);
  50                   mips_classify_address (&addr, tmp, GET_MODE (tmp), true);
  51 -                 if (REGNO (addr.reg) != REGNO (dest))
  52 +                 if (addr.reg && REGNO (addr.reg) != REGNO (dest))
  53                     validate_change (next, &SET_SRC (set), src, false);
  54                 }
  55               else