From a1d50f1d77fcda2c1a299477d44b12760e9c5398 Mon Sep 17 00:00:00 2001
From: rsandifo <rsandifo@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 5 Feb 2007 10:41:26 +0000
Subject: [PATCH] gcc/ * dwarf2out.c (dwarf2out_frame_debug_expr): Record the
register saves in a PARALLEL before the register assignments.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@121594 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/ChangeLog | 5 +++++
gcc/dwarf2out.c | 28 +++++++++++++++++++++++-----
2 files changed, 28 insertions(+), 5 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ad824be9af5c..198dee3817b0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2007-02-05 Richard Sandiford <richard@codesourcery.com>
+
+ * dwarf2out.c (dwarf2out_frame_debug_expr): Record the register
+ saves in a PARALLEL before the register assignments.
+
2007-02-05 Richard Sandiford <richard@codesourcery.com>
* doc/tm.texi (DWARF_ALT_FRAME_RETURN_COLUMN): Do not require
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 6cbf9d3874d4..186c979abb55 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -1524,13 +1524,31 @@ dwarf2out_frame_debug_expr (rtx expr, const char *label)
{
int par_index;
int limit = XVECLEN (expr, 0);
+ rtx elem;
+
+ /* PARALLELs have strict read-modify-write semantics, so we
+ ought to evaluate every rvalue before changing any lvalue.
+ It's cumbersome to do that in general, but there's an
+ easy approximation that is enough for all current users:
+ handle register saves before register assignments. */
+ if (GET_CODE (expr) == PARALLEL)
+ for (par_index = 0; par_index < limit; par_index++)
+ {
+ elem = XVECEXP (expr, 0, par_index);
+ if (GET_CODE (elem) == SET
+ && MEM_P (SET_DEST (elem))
+ && (RTX_FRAME_RELATED_P (elem) || par_index == 0))
+ dwarf2out_frame_debug_expr (elem, label);
+ }
for (par_index = 0; par_index < limit; par_index++)
- if (GET_CODE (XVECEXP (expr, 0, par_index)) == SET
- && (RTX_FRAME_RELATED_P (XVECEXP (expr, 0, par_index))
- || par_index == 0))
- dwarf2out_frame_debug_expr (XVECEXP (expr, 0, par_index), label);
-
+ {
+ elem = XVECEXP (expr, 0, par_index);
+ if (GET_CODE (elem) == SET
+ && (!MEM_P (SET_DEST (elem)) || GET_CODE (expr) == SEQUENCE)
+ && (RTX_FRAME_RELATED_P (elem) || par_index == 0))
+ dwarf2out_frame_debug_expr (elem, label);
+ }
return;
}
--
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