From: Segher Boessenkool <segher@kernel.crashing.org>
To: gcc-patches@gcc.gnu.org
Cc: law@redhat.com, dje.gcc@gmail.com,
Segher Boessenkool <segher@kernel.crashing.org>
Subject: [PATCH 3/5] regrename: Don't rename restores
Date: Fri, 23 Sep 2016 08:23:00 -0000 [thread overview]
Message-ID: <f92b642e30f141bd5a2910b4b422857384d4369d.1474616087.git.segher@kernel.crashing.org> (raw)
In-Reply-To: <cover.1474616087.git.segher@kernel.crashing.org>
In-Reply-To: <cover.1474616087.git.segher@kernel.crashing.org>
A restore is supposed to restore some certain register. Restoring it
into some other register will not work. Don't.
2016-09-23 Segher Boessenkool <segher@kernel.crashing.org>
* regrename.c (build_def_use): Invalidate chains that have a
REG_CFA_RESTORE on some instruction.
---
gcc/regrename.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/gcc/regrename.c b/gcc/regrename.c
index 54c7768..00a5d02 100644
--- a/gcc/regrename.c
+++ b/gcc/regrename.c
@@ -1867,6 +1867,12 @@ build_def_use (basic_block bb)
scan_rtx (insn, &XEXP (note, 0), NO_REGS, terminate_dead,
OP_IN);
}
+
+ /* Step 8: Kill the chains involving register restores. Those
+ should restore _that_ register. */
+ for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
+ if (REG_NOTE_KIND (note) == REG_CFA_RESTORE)
+ scan_rtx (insn, &XEXP (note, 0), NO_REGS, mark_all_read, OP_IN);
}
else if (DEBUG_INSN_P (insn)
&& !VAR_LOC_UNKNOWN_P (INSN_VAR_LOCATION_LOC (insn)))
--
1.9.3
next prev parent reply other threads:[~2016-09-23 8:22 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-23 8:22 [PATCH v3 0/5] Separate shrink-wrapping Segher Boessenkool
2016-09-23 8:22 ` [PATCH 1/5] separate shrink-wrap: New command-line flag, status flag, hooks, and doc Segher Boessenkool
2016-09-26 17:02 ` Jeff Law
2016-09-23 8:22 ` [PATCH 2/5] dce: Don't dead-code delete separately wrapped restores Segher Boessenkool
2016-09-26 16:55 ` Jeff Law
2016-09-23 8:23 ` Segher Boessenkool [this message]
2016-09-26 16:44 ` [PATCH 3/5] regrename: Don't rename restores Jeff Law
2016-09-23 8:33 ` [PATCH 4/5] shrink-wrap: Shrink-wrapping for separate components Segher Boessenkool
2016-09-27 21:25 ` Jeff Law
2016-09-28 9:26 ` Segher Boessenkool
2016-09-28 16:36 ` Jeff Law
2016-09-30 10:14 ` Segher Boessenkool
[not found] ` <20160930102908.GB14933@gate.crashing.org>
2016-09-30 10:52 ` Segher Boessenkool
2016-10-10 21:21 ` Jeff Law
2016-10-10 22:23 ` Segher Boessenkool
2016-09-23 8:44 ` [PATCH 5/5] rs6000: Separate shrink-wrapping Segher Boessenkool
2016-09-26 16:39 ` Jeff Law
2016-09-26 18:16 ` David Edelsohn
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