[openwrt/openwrt] gcc: merge upstream fix for PR 83496 (fixes FS#814)
LEDE Commits
lede-commits at lists.infradead.org
Mon Feb 26 10:15:00 PST 2018
nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/25aaff9100065dba881be71b9dcab1e9cc8a7b5f
commit 25aaff9100065dba881be71b9dcab1e9cc8a7b5f
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Sun Feb 25 20:25:20 2018 +0100
gcc: merge upstream fix for PR 83496 (fixes FS#814)
This bug was causing miscompiled code related to branch delay slots
Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
.../7.3.0/100-PR-rtl-optimization-83496.patch | 136 +++++++++++++++++++++
1 file changed, 136 insertions(+)
diff --git a/toolchain/gcc/patches/7.3.0/100-PR-rtl-optimization-83496.patch b/toolchain/gcc/patches/7.3.0/100-PR-rtl-optimization-83496.patch
new file mode 100644
index 0000000..466a731
--- /dev/null
+++ b/toolchain/gcc/patches/7.3.0/100-PR-rtl-optimization-83496.patch
@@ -0,0 +1,136 @@
+From: ebotcazou <ebotcazou at 138bc75d-0d04-0410-961f-82ee72b054a4>
+Date: Mon, 26 Feb 2018 16:29:30 +0000
+Subject: [PATCH] PR rtl-optimization/83496 * reorg.c
+ (steal_delay_list_from_target): Change REDUNDANT array from booleans to
+ RTXes. Call fix_reg_dead_note on every non-null element.
+ (steal_delay_list_from_fallthrough): Call fix_reg_dead_note on a
+ redundant insn, if any. (relax_delay_slots): Likewise.
+ (update_reg_unused_notes): Rename REDUNDANT_INSN to OTHER_INSN.
+
+git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@257996 138bc75d-0d04-0410-961f-82ee72b054a4
+---
+ create mode 120000 gcc/testsuite/gcc.c-torture/execute/20180226-1.c
+
+--- a/gcc/reorg.c
++++ b/gcc/reorg.c
+@@ -1035,7 +1035,8 @@ check_annul_list_true_false (int annul_t
+
+ static void
+ steal_delay_list_from_target (rtx_insn *insn, rtx condition, rtx_sequence *seq,
+- vec<rtx_insn *> *delay_list, resources *sets,
++ vec<rtx_insn *> *delay_list,
++ struct resources *sets,
+ struct resources *needed,
+ struct resources *other_needed,
+ int slots_to_fill, int *pslots_filled,
+@@ -1048,7 +1049,7 @@ steal_delay_list_from_target (rtx_insn *
+ int used_annul = 0;
+ int i;
+ struct resources cc_set;
+- bool *redundant;
++ rtx_insn **redundant;
+
+ /* We can't do anything if there are more delay slots in SEQ than we
+ can handle, or if we don't know that it will be a taken branch.
+@@ -1087,7 +1088,7 @@ steal_delay_list_from_target (rtx_insn *
+ if (! targetm.can_follow_jump (insn, seq->insn (0)))
+ return;
+
+- redundant = XALLOCAVEC (bool, XVECLEN (seq, 0));
++ redundant = XALLOCAVEC (rtx_insn *, XVECLEN (seq, 0));
+ for (i = 1; i < seq->len (); i++)
+ {
+ rtx_insn *trial = seq->insn (i);
+@@ -1151,7 +1152,10 @@ steal_delay_list_from_target (rtx_insn *
+ we therefore decided not to copy. */
+ for (i = 1; i < seq->len (); i++)
+ if (redundant[i])
+- update_block (seq->insn (i), insn);
++ {
++ fix_reg_dead_note (redundant[i], insn);
++ update_block (seq->insn (i), insn);
++ }
+
+ /* Show the place to which we will be branching. */
+ *pnew_thread = first_active_target_insn (JUMP_LABEL (seq->insn (0)));
+@@ -1198,6 +1202,7 @@ steal_delay_list_from_fallthrough (rtx_i
+ for (i = 1; i < seq->len (); i++)
+ {
+ rtx_insn *trial = seq->insn (i);
++ rtx_insn *prior_insn;
+
+ /* If TRIAL sets CC0, stealing it will move it too far from the use
+ of CC0. */
+@@ -1209,8 +1214,9 @@ steal_delay_list_from_fallthrough (rtx_i
+ break;
+
+ /* If this insn was already done, we don't need it. */
+- if (redundant_insn (trial, insn, *delay_list))
++ if ((prior_insn = redundant_insn (trial, insn, *delay_list)))
+ {
++ fix_reg_dead_note (prior_insn, insn);
+ update_block (trial, insn);
+ delete_from_delay_slot (trial);
+ continue;
+@@ -1790,15 +1796,14 @@ fix_reg_dead_note (rtx_insn *start_insn,
+ }
+ }
+
+-/* Delete any REG_UNUSED notes that exist on INSN but not on REDUNDANT_INSN.
++/* Delete any REG_UNUSED notes that exist on INSN but not on OTHER_INSN.
+
+ This handles the case of udivmodXi4 instructions which optimize their
+- output depending on whether any REG_UNUSED notes are present.
+- we must make sure that INSN calculates as many results as REDUNDANT_INSN
+- does. */
++ output depending on whether any REG_UNUSED notes are present. We must
++ make sure that INSN calculates as many results as OTHER_INSN does. */
+
+ static void
+-update_reg_unused_notes (rtx_insn *insn, rtx redundant_insn)
++update_reg_unused_notes (rtx_insn *insn, rtx other_insn)
+ {
+ rtx link, next;
+
+@@ -1810,8 +1815,7 @@ update_reg_unused_notes (rtx_insn *insn,
+ || !REG_P (XEXP (link, 0)))
+ continue;
+
+- if (! find_regno_note (redundant_insn, REG_UNUSED,
+- REGNO (XEXP (link, 0))))
++ if (!find_regno_note (other_insn, REG_UNUSED, REGNO (XEXP (link, 0))))
+ remove_note (insn, link);
+ }
+ }
+@@ -2324,9 +2328,8 @@ follow_jumps (rtx label, rtx_insn *jump,
+ taken and THREAD_IF_TRUE is set. This is used for the branch at the
+ end of a loop back up to the top.
+
+- OWN_THREAD and OWN_OPPOSITE_THREAD are true if we are the only user of the
+- thread. I.e., it is the fallthrough code of our jump or the target of the
+- jump when we are the only jump going there.
++ OWN_THREAD is true if we are the only user of the thread, i.e. it is
++ the target of the jump when we are the only jump going there.
+
+ If OWN_THREAD is false, it must be the "true" thread of a jump. In that
+ case, we can only take insns from the head of the thread for our delay
+@@ -3117,7 +3120,7 @@ relax_delay_slots (rtx_insn *first)
+ /* Look at every JUMP_INSN and see if we can improve it. */
+ for (insn = first; insn; insn = next)
+ {
+- rtx_insn *other;
++ rtx_insn *other, *prior_insn;
+ bool crossing;
+
+ next = next_active_insn (insn);
+@@ -3223,8 +3226,9 @@ relax_delay_slots (rtx_insn *first)
+ /* See if the first insn in the delay slot is redundant with some
+ previous insn. Remove it from the delay slot if so; then set up
+ to reprocess this insn. */
+- if (redundant_insn (pat->insn (1), delay_insn, vNULL))
++ if ((prior_insn = redundant_insn (pat->insn (1), delay_insn, vNULL)))
+ {
++ fix_reg_dead_note (prior_insn, insn);
+ update_block (pat->insn (1), insn);
+ delete_from_delay_slot (pat->insn (1));
+ next = prev_active_insn (next);
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