From f40ce450f3c4b1cfd0a7e9c68e0c2a60d04b2a03 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Sun, 7 Jul 2019 09:49:14 +0000 Subject: [PATCH] Fix uninitialised use in mips_split_move While testing the fix for PR91068, I hit an rtl checking failure while building newlib. mips_split_move was decomposing an address that happened to be symbolic and then tried to access the REGNO of the base register field, which wasn't initialised but which by chance pointed to valid memory. 2019-07-07 Richard Sandiford gcc/ * config/mips/mips.c (mips_split_move): Zero-initialize addr and check whether addr.reg is nonnull before using it. From-SVN: r273174 --- gcc/ChangeLog | 5 +++++ gcc/config/mips/mips.c | 4 ++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index edb8df5..13622c8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2019-07-07 Richard Sandiford + + * config/mips/mips.c (mips_split_move): Zero-initialize addr + and check whether addr.reg is nonnull before using it. + 2019-07-06 Jakub Jelinek * omp-low.c (lower_rec_input_clauses): For lastprivate clauses in diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c index cbebb45..e0535b1 100644 --- a/gcc/config/mips/mips.c +++ b/gcc/config/mips/mips.c @@ -4849,7 +4849,7 @@ mips_split_move (rtx dest, rtx src, enum mips_split_type split_type, rtx insn_) can forward SRC for DEST. This is most useful if the next insn is a simple store. */ rtx_insn *insn = (rtx_insn *)insn_; - struct mips_address_info addr; + struct mips_address_info addr = {}; if (insn) { rtx_insn *next = next_nonnote_nondebug_insn_bb (insn); @@ -4862,7 +4862,7 @@ mips_split_move (rtx dest, rtx src, enum mips_split_type split_type, rtx insn_) { rtx tmp = XEXP (src, 0); mips_classify_address (&addr, tmp, GET_MODE (tmp), true); - if (REGNO (addr.reg) != REGNO (dest)) + if (addr.reg && REGNO (addr.reg) != REGNO (dest)) validate_change (next, &SET_SRC (set), src, false); } else -- 2.7.4